Rainy Day - No Kites to Fly

I've been on vacation for the past week, but the weather has been rainy and I've had a cold most of the time. So I've been out a total of two times with my kite gear, and I have very little to show for it. I could be depressed, or...

I could start a shop project!

Ok, to be fair I finished a shop project. This one has been hanging around for almost a year now: the new kite line winder. I started CAD drawings last year, beginning with a design that's sold commercially under the name "Windbreaker". One of the people on the KAP forum described it as "Knucklebreaker" because of the handles, bits, and pieces that hang out when it's rotating, so I moved away from it. Erick, one of the KAPers from Germany, posted pictures of his winder, and I liked it. So that's the direction my CAD drawings went.

A few weeks ago I picked up the 1/2" baltic birch plywood I needed for the project, and I finally got around to cutting out parts. Over the last week I've sanded, tung-oiled, and finished building the thing.

(Yes, that photograph was taken outside my house... in the rain... It really hasn't let up much.)

It's heavier than my old winder, but a lot more solid and way easier to hold. I haven't had the chance to field test it yet, but if the weather clears any time in the next few days that's my top priority.

The center grip is a wheel off of a scooter that was run over by a car. The bearings are still good, so I stuck with the originals. If they start to go, I've got a tube of ABEC7 bearings I picked up to replace the ones in my Foredom handpieces. That was years ago. Dang Foredom makes a good product.

The winder handle is a piece of 1" diameter Delrin, bored out to ride on a stainless sleeve that's pinned in place by a 1/4" bolt. The design for this part started out using bearings as well, but there's really no point since Delrin is a bearing material, and it rides great on the stainless. So the design was simplified. I tried to make it comfortable to hold, but if it needs adjustment it's a simple lathe job.

The row of holes out toward the edge of the winder is so the line can be clipped off with a carabiner to fix it to a particular length. This lets me put out, say, 200' of line, clip off, anchor, and attach my rig.

So far I'm pleased with the winder, but it does mean changing some of my procedures in the field. My previous winder had a hole clear through it, so it was pretty easy to clip off the line, shove the winder up onto my arm, and use both hands to hang the rig or use the transmitter. This winder won't allow for that, so I'll have to work out new procedures.

I do like the larger moment arm on the winding handle, and the free-spinning bearings on the grip. I think it'll be a lot easier to bring line in. That might offset any inconvenience the lack of a through-hole will present. Time will tell.

I'll write more once I have a chance to field test it.

Tom

Toys from the Shop

Having a home shop isn't all about making tools or making parts. Some of the most rewarding projects I've done have been toys, or repairs for toys. With the holidays drawing on, it's fun to make toys in the shop to share as presents, or simply to share as soon as they come off the lathe or mill.

A little while ago I got back into making tops. Nothing advanced, just something fun to make on the lathe and share. It's the kind of thing anyone with a few shop tools could do. I did this one on a Taig lathe, which is a small benchtop lathe originally designed for making contact lens molds. I've never used mine for work as fine as that, but for things like this little top it's ideal. The same kind of thing could be done on a drill press with some files and a little more time, though.

The big trick with tops is that everything has to be coaxial. If you have any part of the top off the centerline, the top will wobble. Wobbles rob the top of kinetic energy and make it spin for a shorter time. The more concentric and coaxial you can make it, the better.

For this one I chopped off some 1/8" diameter brass rod, chucked it in a collet chuck, and cleaned up both ends. I then drilled some 1" diameter Delrin undersize and pressed the rod in place. The assembly then went back in the collet chuck. I also chucked up a bearing with a 1/8" ID hole in the tailstock, and brought that in as a live center to support the outboard end. The body of the top was then cut using an 0.060" parting tool. Not the best way to go about it, but it got the job done. I wasn't all that careful about the actual depth of cut, but I made each pass in 0.050" steps.

This top will easily spin for over a minute. It's not that hard to do, and the kids have a blast with them. Larger tops will have longer spin times, and certainly better thought out ones will spin longer.

For the ultimate in spinning top design, look no further than the mathematics for calculating steam engine flywheels. Ever wonder why the flywheels on steam engines are spoked? If you look at the math for the kinetic energy of a rotating annulus, you find that for a given outside diameter, there's a break even point on the inside diameter where you stop benefiting from additional material. Inside that ideal ID, steam engine designers would spoke out the wheel to cut weight and save iron.

The fine-tuning of spinning top design reached something of a pinnacle in the Quark, a top designed by Jim Lewis, who incidentally also started up the eMachine Shop company. What sets the Quark apart, aside from being a very efficient flywheel design, and having a shaft that is designed to get the most speed as possible out of the human fingers, is that it can be dynamically balanced to remove almost all residual wobble. The tops come with a laser pointer and a set of counter weights that can be installed in pockets underneath the outer rim of the top. By reflecting the laser light off the top surface, it's possible to visualize the wobble in the top and balance accordingly. Spinning times of fifteen minutes or more are common.

But they also take considerably longer to make, and are made to much tighter tolerances than my little Delrin and brass top. For the purpose of cranking something out in the shop you can hand off to a kid and watch them have fun, sometimes the simpler approach is more effective.

Tom

Back to the Shop

For a while there photography took over my blog. No problem there, I enjoy photography and I will continue doing so. But it took over my blog at the expense of the shop, and that will never do.

There are some projects on the horizon that will require the Tiny Machine Shop be active again. On the short list are some woodworking projects, at least one electronics project, and two machining projects. It's good to get back out in the shop!

Rather than water down the posts between machining and photography, I've moved the photography posts over to a new blog strictly for them:

The View Up Here

Since it is a new blog, I'm going to start over at the beginning and describe kite aerial photography in a way that should help someone who's interested to get going with it. I hope you'll give it a look.

In the meanwhile I plan to get my shop cleaned out, get the new projects lined up, and start posting about them as well. Stay tuned!

Tom

At Long Last - Waipi`o Valley

After a year of trying, on and off, I finally flew a camera in Waipi`o Valley.

The history of Waipi`o, like the history of Hawai`i itself, is long, varied, and way too easy to simplify at the expense of the really interesting bits. (If that doesn't get you Googling "waipio valley" then I didn't do my job right.)

Since human occupation of the Big Island, it has been used for agriculture with few interruptions. In pre-European-Contact days, at various times it supplied the Islands with food during times of drought. In post-Contact days, it continued in the role of being one of the major agricultural concentrations in the Islands. In the early 1940's it was heavily populated and cultivated. But the tsunami of 1946 wiped out almost everything in the valley, and few of the residents who had spent their lives there felt inclined to return.

Nonetheless people did come back, and to this day it is still being farmed by people who choose to risk the tsunamis, the floods, and the other conditions that can happen there. It's not hard to see why.





The biggest problem with doing KAP in Waipi`o is that the prevailing winds come up the coast and around the cliffs to the south. This windward view pretty much tells it all. Cliffs almost a thousand feet high make for interesting wind inside the valley. I found three distinct strata, all within 500' of the valley floor. "Turbulence" is putting it mildly. Nonetheless, the wind was steady enough for me to take several panoramic sequences.





So what was the trick? Using the right kite, of course. On previous attempts I'd flown a Flowform 16, which needs a fair bit of wind in order to fly a camera. I started with the Flowform, but switched to my 6' Rokkaku that my friend made for me. It can fly the camera with less wind, at a higher line angle, and because it's framed in fiberglass it can deal with the gusts better than a carbon fiber framed kite would be able to.

Even so, toward the end it was catching more wind than it could handle. After landing the camera I had a bit of a fight on my hands to get the kite down safely. Luckily the Rokkaku takes its origins from a Japanese figher kite, and as such its moves are actually pretty predictable and very well documented. In a power-dive you let out line quickly, and the kite rights itself and heads for the sky. I had two power-dives, both of which turned around quickly with careful line handling. In the end all my gear made it down in one piece.

It's been a long time since I've done any KAP worth posting. I couldn't be happier with how the day turned out.

Tom

Pumpkin Carving

Since I was home sick most of last week, pumpkins didn't get carved in a timely fashion. To put this another way, we were gutting them less than an hour from when the kids suited up to go tricking and treating.

Time was not my friend...

In the past I developed a pretty reasonable set of tools for working on pumpkins. My favorite is a jigsaw blade I stuck on a plywood handle. I've found no better tool for opening holes in pumpkins. It makes the commercially available tools look pitiful. At some point I need to mount it in a proper handle and make it permanent. For now, it's working great.

The big addition this year was the Foredom flex shaft tool. I'd heard in the past that Dremel tools really didn't work on pumpkins. But I'm beginning to suspect that is incorrect, and that it was the burr that was at fault. I did try a stock Dremel burr in my Foredom, but it had a rotten time cutting.

The two burrs that really worked well were carbide burrs used for machining PC boards and the Tornado structured tungsten carbide bits that Woodcraft sells for doing woodworking with Foredom tools. At 14k RPM, these essentially liquefy the pumpkin. There's very little side-force on the handpiece as you pull it through the pumpkin, and the Tornado bits like to cut at a single depth, so you're not constantly fighting dig-ins.

In the end I was able to do two pumpkins, beginning to end, in less than an hour. One was a ghost design with two cut depths. The other, a cat designed by my daughter, was completely silhouetted. Both worked out great.

I learned something else during all this: The tradewinds were howling last night, and in previous years that would've blown out our candles. This year neither pumpkin had through-holes, except for the chimney hole at the top and two vent holes at the bottom so we could get an updraft through the pumpkin. Using pumpkins without through-holes meant the candles never had direct wind blowing on them, and consequently neither one blew out.

The kids were pleased as punch, and now I have a new tool to bring to bear on pumpkin carving next year. But first, I'd like to get some more Tornado bits!

Tom

Life is Strange

So one of my pictures hit a first page Google search.

A while back I was looking over old picture stats, trying to figure out which archive shots I should go back and print for a gallery showing in town. Lo and behold, my honu-from-above picture was no longer the most viewed picture in my Flickr stream. It was... an infrared grab shot I took over the fence to test out a filter stack.

??!

Some searching through stats showed that the bulk of the traffic to that image came from image searches on Google. (Thank you, Flickr, for storing the originating URL for incoming links!) A little more clicking indicated the search terms were "Canon A650". Yep, anyone looking for information on the A650 would run across this one oddball image.

So I tried it. I did a Google search on "Canon A650", clicked "Images", and lo and behold there it was. My neighbor's fence, Kohala in the background, and my ficus trees glowing in wonderfully infrared-lit chlorophyll heaven.

Great...

So despite all the large format photography I've done, the macro shots, the kite aerials, the big panos, the HDR, despite all that, it was a quickie test shot that finally made the big time. Life is strange. And to think I almost didn't post it. I was just excited about the IR response of the unmodified A650, and wanted to share.

Tom

Preparing for the Heiau Flight

In an earlier post I made reference to an upcoming trip to Ahu A'Umi Heiau on the Big Island of Hawai`i. We'll be at the Heiau on the 15th and 16th, and during that time the plan is to collect at least 4000 images from aerial cameras so that a 3D model of the site can be built using photogrammetry. I'm not a GIS specialist. I'm not an archaeologist. And I've never used photogrammetry software in my life. I get to go because I'm going to be operating one of the two aerial cameras. Life is good.

The big gotcha with the site is that there's very little wind. In the mornings, 0-2 kts is typical. By mid-afternoon, if the site sees 8-10 kts, it's a blustery day. By way of comparison, Kua Bay typically sees 12-14 kts, and Waimea can see 20+. I have a good range of kites for the winds I expect to fly in, but my lower limit is right around 10 kts with the 6' rokkaku. For the trip to work, I needed a lighter camera, and a lighter wind kite.

Since the photogrammetry software mostly needs down-looking shots, I built out a lightweight rig with a fixed orientation. This cut the rig weight in half. Running a CHDK intervalometer script meant no radio or AuRiCo, batteries, etc. on board. For my birthday my wife got me a Fled from Brooks Leffler. It's a lighter wind kite than the rokkaku, but it's not really intended to haul around an 800g + rig. But for the lightweight rig it's well-matched.

Sunday a friend invited me out to Kite Day in North Kohala. I'd never been, and really didn't know what to expect. But I grabbed my gear and went. I had a blast.

Among other things, Chris, the co-owner of Hawi Headquarters, brought a Premier Kites 19' Delta from his shop. That thing is huge! At one point the wind lulled, and the big delta started circling down. I pulled in line to get it to catch again, and WHOMPH! It filled and started pulling like a horse. It's a beast. Chris and I spoke about the upcoming trip, and in the end he wound up showing me how to set up and take down the big delta, and loaned it to me. Considering the sticker price for the thing is almost $450, that's a heckuva loan.

From what he said it'll fly in two knots of wind, so even if the afternoon wind at the Heiau is good, this kite will potentially extend our shooting into the early morning hours. And if the wind never picks up enough to fly some of the other kites, it may be our only way to get data. No matter what, it makes for more time int he sky. More time in the sky = more data for the photogrammetry suite to work with = better model. Can't beat it. (Thanks, Chris!!)

So with new tires on my Jeep and a day planned on the lift to change out all of its bodily fluids, I'm ready and rarin' to head up Hualalai and fly cameras at the Heiau. A new kite of my own, and a loaner kite that's got more lift than I know what to do with, I can hardly wait.

Tom

Photo Competition and Exhibition

For better or worse, I entered a black and white photography competition. Rather, I should say I entered it three times. They didn't place any restrictions on the number of entries you can submit, but each one carries with it a $15 entry fee. Three seemed like a good number.

Whether it was a conscious choice or not, the three pictures I entered do a good job of demonstrating the kinds of photography I do. One was a large format macro shot, the second was a digital ground shot, and the third was a KAP shot. The large format shot started life as a black and white negative, but the other two had to be converted from color images. It was easy for the digital ground shot, but easier said than done for the KAP shot. In the process I learned that most of my KAP images really do need to be color in order to work. A handful can be used either way, and some, by the nature of the subject, already are black and white pictures. But for the theme of the competition, my choice took some work.

And in the end, I wound up shooting myself in the foot.

To be fair, this is my first photo competition. So I don't have a lot of experience to compare with. Still, the rules were unclear on several points, and I wound up hurting my chances as a result.

The way the rules read, photographers submit non-returnable prints or slides. Submissions are then reviewed by a panel of judges. The judges select which photos should be hung in the gallery, and inform the artists. The artists then make their final prints and mat and frame them for hanging. Once the photos are hung in the gallery, the photographers and general public are invited to view them.

A photograph may win the judges' award, the people's choice, the photographer's choice, and/or the grand prize. So they're judged at least three separate times. The rules don't explicitly say how the grand prize is decided, but my guess is it is a compilation of the points from the three rounds of judging, with the highest tally taking the prize.

Here's where it gets fuzzy, though. In reading and re-reading the rules, I get the feeling the judges' award is based on the submissions, not the hanging work. I chose to print my submissions on 8.5x11 matte photo paper rather than slides since that is the medium I intend to use for my finished pieces. But the finished pieces are intended to be printed 18"x24", with the matte and frame bringing that up to roughly 24"x32". So potentially two of the rounds of judging will be done on the 18"x24" size, and the third on a much smaller size.

Kinda wish I'd submitted slides, which are projected for the judges to view. Say what you will, the size of a photograph determines, to a large extent, the emotional impact it has with the viewer. Take your favorite Ansel Adams print and print it 5"x7". Hang it on the wall next to one of his more typical prints in the 36"x48" size. Which one grabs your eye? Which one takes your breath away? Ok, I really wish I'd submitted slides.

But such is life. I honestly don't think any of my pictures stand a strong chance of winning. I've reviewed winning photos from previous years, and it's a style of photography I really don't do. I also don't think I carry the clout, as a photographer, to wow the judges and public strongly enough to make them choose a photograph outside of their comfort zone.

My intention was not to compete so much as to get my work shown. Even if one of my pictures makes it to the gallery, I'm happy. It will mean someone is getting to see it. I do a so-so job of marketing my photos online, but I do a downright terrible job of marketing them locally. This is the first in several efforts to address that.

As a side benefit, all the photos hung in the gallery are up for sale. That's in the rules, too. In previous years, almost all the artwork in the gallery sells. So it's not only a nice marketing venue, it's also an opportunity to make a sale. Can't beat it. My goof-up isn't looking so bad now.

Still, I learn from my mistakes. Next year? I'm getting slides made.

Tom

A Change in Direction

The past few weeks have been rough, both at work and as far as my hobbies are concerned. We had a failed mirror coating, and a thin coating on our second attempt shook our confidence in our process and our equipment. We've spent the past few weeks thinking through all the what-ifs, and ordering new supplies to replace what we used. Because of all this our secondary mirror's coating schedule had to be bumped, but not by enough to actually test our equipment in the mean time. We're going into it blind, not knowing if we'll get a good coating. Stressful? You bet.

In conjunction with this, the weather has been utterly uncooperative for photography. Every weekend, the wind dies and the volcanic gasses start piling up. At one point visibility dropped to less than a quarter mile. The view from my house, normally good incentive for me to get my camera and head out the door, was a uniform gray. On those rare days when the weather was clear, invariably something had already been planned, and photography wasn't part of it. Frustrating? You bet!

When the weather is bad, the only thing you can do is live with it. Read a book, surf the web, or look at other people's pictures to get new ideas of where to fly. I did a little of each. It didn't help.

I've known for some time there was a sameness to my pictures. But after surfing thousands of pictures of Hawai`i, I found there's a sameness to a lot of pictures taken here. It's because even with the variations from island to island, even with all the climates the Big Island has to offer, there are limits. You can only drive the same road so many times before it stops being something new. There are only so many times you can see the sun setting over the ocean before even a photographer says to himself, "Yep, seen that."

I need a change.

In a small way, at least, I do have a change coming up. Most of my KAP shots have been coastal, but there's a trip to map a heiau between Hualalai and Mauna Loa, and I've been invited to participate. Two of us will be flying KAP rigs over the heiau in order to gather the shots necessary for the photogrammetry software to do its thing and create the 3D model of the site. The altitude is of the site is almost a mile above sea level. Not enough to cause real problems, but enough to make wind requirements an issue.

I know I can fly my full RC KAP rig in ten knots of wind using my rokkaku. At 5000', that requirement goes up because of the thinner air. But the wind at the site rarely goes over 8 knots, so flying that rig is iffy at best. Since the shots required are all straight down, and since I need a lighter rig to fly, I made one specifically for the purpose.

It uses the same camera as my RC rig, a Canon A650 IS running CHDK. I've got an intervalometer script loaded on the camera, so it's a straightforward matter of dialing in the number of seconds between exposures, and sending the camera aloft. At just over 400g of mass in its ready-to-fly configuration, it's about half what my full RC rig weighs. And it packs small enough it will fit into a pocket of my KAP bag.

Planning the trip, building the rig, thinking through all the technical issues I'm likely to run into, it's all helped. But it's not really enough. I really need a more substantial change than that.

One thought I've been toying around with for the past six months is the idea of becoming a semi-professional photographer. I can't see myself making a living at it full-time, and I have no intention of quitting my day job, despite the heartache it's caused recently. But at the suggestion of a friend and fellow KAPer, I picked up a copy of Dan Heller's Profitable Photography in the Digital Age. It's a good book, and well worth the money. It also spelled out a lot of reasons why going semi-pro is probably not the right answer to the problems that have been dogging me. If anything, it would up my frustration level worse than it is now.

Today I was re-reading John Shaw's Business of Nature Photography, and came across one of his points about how to break into the nature photography business: publish articles that use your photography. I literally smacked my forehead! I know I'd read those same words years ago when I first bought his book, but for some reason I'd forgotten them.

A few years ago, I wrote some articles for Digital Machinist, one of the trade publications I take. I enjoy writing, and the articles were fun to do. I even published some pictures with them, though they weren't the greatest example of studio photography I've seen. I have some other articles lined up, but there's a big difference between doing machining and documenting machining as you do it. Photographing a machining process makes it take about ten times longer, and because you're constantly fiddling with the camera setup and the machining setup, it can be a frustrating way to get a job done. At some point I'll get back to those articles, but I'm not in a huge hurry.

Even after Digital Machinist had published my articles, it didn't occur to me that I'd done exactly what Shaw had recommended. Not until I re-read his book. The thought of applying this to my photography had simply never entered my mind.

But even I can put two and two together when they're put in front of me with a big neon sign. I live in a unique place. I do a fairly unique form of photography. And I know I can write since a publisher saw fit to print my work on more than one occasion. Hey, I can do this!

The next step, of course, is to come up with ideas for articles and to do market research into the publications likely to carry them. Travel magazines, airline in-flight magazines, photography magazines, and possibly even machining magazines are likely ones to try the ideas on. Travel destination articles, articles describing rig fabrication or camera fabrication, even educational how-to articles for teacher publications are all fair game.

The weather is a little better today, but I think it's the new hope for three hobbies I truly enjoy that's made for the change in outlook. Life is getting interesting again.

Tom

More on the Feather

So far my results with the KAP Feather are mixed. I flew in two spots with wildly different wind on two different days.

Day one was at Upolu Point in 20+ knot wind (closer to 22+ knot wind). I flew my Flowform 16 despite the wind speed, and managed to get good altitude, regardless of the thing "pulling like a truck" as Brooks Leffler described it. It's a good description! At the tail end of the flight I finally had to clip off to a fence post and walk the kite down with a carabiner. Even hand-over-hand, I couldn't get the thing down any other way.

I flew with the long pan axle, with and without the KAP Feather. In high wind like that, the KAP Feather tended to cause the rig to make small amplitude, high frequency oscillations. I put a lot of this down to tuning. The KAP Feather offers a lot of range for tuning simply by sliding the feather forward and aft on its central spar. I ran at full length, which was probably too much leverage for my rig.

Removing the KAP Feather resulted in larger amplitude, lower frequency oscillations. Pointing was still tough to determine, but the overall angular rate was lower, which resulted in fewer blurred shots. This is how I flew for the remainder of the day.

The second day was in my neighborhood, with Kona winds. These are typically more stable than the Trades we get here because the Trades tend to be stirred up from blowing over Kohala Mountain. Still, it made for a lot of oscillations, and I eventually took it off and flew without.

By the end of the day I removed the long pan axle from my rig and put the Picavet back on top of the pan axis gear box. Dang...

I'm not ruling out the KAP Feather. Far from it. I don't think I've given it a fair shake yet. But I also don't know if my digital KAP habits and flying requirements really jive well with it. I've already come up with a combination of camera settings and flying conditions that work well for me. I'll need to come back to the KAP Feather another time.

The jury's still out on my 4x5 camera, though. I do think it needs something along these lines to stabilize it, along with higher flying mass to offset its large cross-sectional area. There's a lot of exploration to be done along these lines. Only time will tell.

The incident tally for the day included one kite marked in a cat battle (rinsed, drying in my room now), one rig rolled about four times on the ground (thank goodness I got an extra set of Broox leg brackets!), and no real shots to show for it. Ah well.

Tom

Feather in the KAP

My KAP Feather came in today. Sorry, no pictures and no wild wind reports yet, but they'll be along shortly.

Prior to my ordering the KAP Feather, a discussion came up on the KAP forum about suspension stability vs. pan axle length. Because the KAP Feather puts a fairly large obstruction at the downwind side of the rig, it includes an extra long pan axle so the camera is positioned underneath the obstruction. So I now have a chance to try three configurations at once: Original, Long-Axle, and Long-Axle with Feather.

The ideal way to test this would be to get a 6DOF IMU and a data logger, and fly each of the three configurations under the same wind conditions. Mmmm... Not gonna happen. I can't shell out the $300+ for the IMU, and the only person I know who owns one needs it for their own project (a quadracopter). But I do have the next best thing: a camera.

While developing the 4x5 box camera, Henry Jebe suggested mounting my digital camera somewhere on the rig so I could shoot video during a flight. The videos I've shot from a KAP rig have been pretty wobbly because of all the rig motion, but as Henry pointed out, what better way to measure the wobbliness! Give a nice ground-level pano of the scenery, you should be able to get angular measurements between landmarks, and not only get a good idea of the overall motion of the rig, but be able to turn it into angular rates. Fly each of the three configurations, and you have a good idea of what each one will do.

One encouraging point is that Mike Jones from Jones Airfoil, the designer and manufacturer of the KAP Feather, shoots HD video from his rig. Given my own experience with low-def video, if he's getting enough stability to shoot HD, the Feather will do an admirable job. I'm looking forward to trying it in the field this weekend.

The one question I still have to answer is transport. Right now everything packs down into a backpack, and is quick to set up in the field. The longer axle on the pan axis won't fit into my pack. So chances are I will have to come up with some sort of release system so I can remove the Picavet from the top of the rig, and remove the KAP Feather from the Picavet. Starting to get complicated.

But it really doesn't have to be. I just need to find the right way to work it, and it'll be fine.

So the next question is what to do with the 4x5 rig. I ran the idea of adding stabilization to it past Mike Jones, and it looks like he's got some ideas. Work's been too busy for me to do much with it, but I hope to talk to him in the next week or so and get some direction.

Lots to look forward to.

Tom

Filters in my Bag

My new Hoya CP filter came in yesterday. It was overcast, so I didn't have a good opportunity to try it out. It's has multi-layer AR coatings on each face, so it should have less ghosting than the Tiffen I've been using, and the filter is only 5mm thick, so I might not even get the vignetting I sometimes got with the Tiffen. Time will tell.

As I tucked it into my KAP bag and put the Tiffen back in the DSLR bag, it got me to thinking: The filters I keep in my bag have sure changed!

When I started off with 35mm, I kept UV filters on the ends of my lenses. I thought it a necessity, a way to protect my lenses against smudges and scratches, and at that stage it probably was. But over time I learned how to be paranoid about my lenses, and the UV filters did little more than filter out UV light. Eventually they came off, and spent more time in the filter bag than on the lenses.

Early on I got a circular polarizer. That Tiffen CP I used for KAP is the same one I got back in '95 for 35mm. It's probably time to change it out since the optical surfaces aren't what they once were, but it's still in use. Case in point, I keep one in each camera bag. The only bag that doesn't have a CP is my 4x5 bag, and I'd be interested in changing that.

I shot enough B&W film through 35mm cameras that I got a fairly good set of Wratten gel filters for B&W work. #25 red, #47A blue, a #90 viewing filter (for me, not the camera) were my main ones. I also got a #12 deep yellow, #8 yellow, and #58 green which didn't see as much use, but were good to have. When I started shooting more 4x5 B&W than 35mm, these moved to the 4x5 bag. It turns out the #58 green is good for shooting black lava rock beaches, so it will probably find its way into the 4x5 KAP bag.

In the days of film, you couldn't white-balance to correct for color shifts. I kept filters for fluorescent and tungsten lighting to shift their white point closer to outdoor conditions. I shot a lot of color slide film, balanced for outdoor shooting. So for the lab shots I did at the time this was a big boon. With digital cameras, they're really not necessary any more. And with my film work now being only B&W, they went in the filter bag with the UV filters, probably never to be seen again.

One set of filters I haven't removed is the split ND filters. These are rectangular pieces of acrylic that are clear at one end, and have a neutral density tint at the other, with a transition between the two in the middle. Slide film has about five stops of dynamic range. If you're shooting a scenic, and the sky is three stops lighter than the foreground, metering the foreground puts it in the middle of your dynamic range, and puts the sky at a blown-out white. Pop a two-stop split-ND filter on the end of the lens and slide it down until the transition puts the ND over the sky and the clear over the foreground, and the sky will come out one stop lighter than the ground. Neat stuff!

"But with digital, you don't really need to do that!" Well, yes you do. Or rather you should consider it. True, you can dodge and burn in programs like Photoshop and Gimp, but you only get so many bits per pixel. Even if you have any texture left in the sky at all (which at three stops you wouldn't), chances are it'll look posterized by the time you're done with it.

"But with HDR, you don't need to do that, either!" True, and the next time you try to do an HDR wildlife shot of a running deer, let me know how it turns out. I'm not pooh-poohing HDR. I think it's a great technique. But to say that one technique invalidates another one is the wrong way to look at it. Each has its place, and the split-ND filters still live in my DSLR bag. (Heck, I can't wait to try HDR with split-ND!)

Why use filters at all? That's actually a really good question. Everything you stick in front of a lens will affect the final image quality. Filters are planar-planar optics, which when stuck in a converging beam will introduce spherical aberration into the optical system. Unless you have a really good reason to use one, a filter only degrades your image. In one of John Shaw's books he posed a really simple test: Unless you can vocalize a particular photographic reason to use a filter, don't use one.

For example: "The reflection off the vegetation in this shot is washing out the color, and de-saturating the image. A circular polarizer will let me cut the reflections and bump the color in the leaves."

Another: "My digital camera has seven stops of dynamic range. The foreground in this shot is three stops darker than the sky. Metering off the foreground will blow out the sky. A 2-stop ND filter will bring it within the range of the camera's sensor, and bring out the texture in the clouds."

But here's the worst: "My friend always said to keep a polarizer on your lens." Errr...

Each time I use a filter, it's a conscious choice to address a particular photographic problem I'm facing. Daylight balanced film under fluorescent lighting used to be one I had to deal with. I don't now, so that filter has gone by the wayside. Flying my KAP rig over a reef and wanting to cut the surface reflection is one I deal with these days, so keeping a circular polarizer in the bag is entirely justified. B&W and the Wratten gels are as natural a choice as when Ansel Adams was using them decades ago. Be aware of what you're doing when you choose to use a filter, and make sure it does what you intend.

Tom

Digital Zone System

Ever since getting into large format photography, I've used the zone system to set up my exposures. This is a system of sensitometry used and taught by Ansel Adams, and was the culmination of years of testing and in-the-field experience by him and his colleagues. By being aware of the dynamic range of your film, and knowing what you could do in the darkroom to compress or expand that range, it let you meter a scene and very precisely predict how it would be rendered on film. I won't presume to go into a full description of the zone system because I can't do as good a job as Adams himself. For that, see his book, "The Negative".

I admit I'm lazy when it comes to digital photography, though. I don't use the zone system, and I slip into complacency when metering, trusting the camera's electronics to do a better job than I can. This is a terrible way to operate! The camera may have a very good idea of how to render a particular tone as an 18% gray, but it has no clue whatsoever what the photographer had in mind for a scene!

Here's a good example: You're shooting a sunset, and want to get a foreground palm tree to show up as a silhouette against the glowing sky. So you whip up your camera, half-press the shutter button to meter the scene, and expose. Trusting to fate, you go about your business, only to find out later that the tree is rendered as a muddy, dim, tree-colored mess, and the sunset sky is blown out. Grrr! Photoshop can fix this by fiddling around with levels and curves, but the resulting picture looks almost Technicolor because the dynamic range has been squeezed around so much.

Better to meter the scene, know how bright the tree is, and set your camera so you know the tree will come out black, and the sky will be rendered in all its glory. To get there, though, you first have to know the dynamic range of your camera.

Regardless of whether you're shooting film or digital, the way to test the dynamic range of your detector is to shoot a textured, uniform-toned subject at various exposure settings, and look at the shots. Below a certain exposure value, it should render as pure black. Above a certain exposure value, it should render as pure white. Between those values is the dynamic range of your detector. Film, CCD, CMOS, doesn't matter.

Most B&W films exposed and developed normally give you about ten stops of dynamic range. You can tweak the developing to change that, but that's the base point. Color films typically gave you about seven stops of range. Color slide, about five. But it's always best to test it yourself and not trust to fate! I always tested a new film before taking it out in the field. Why should digital be any different?

I set my camera, a Canon PowerShot A650 IS at ISO 100, and pointed it at my trusty textured white target, a block of styrofoam. (Hey, better for it to wind up in my studio than in a landfill!) With the camera set on manual and the aperture fixed at f/8, I ran exposures from 1/2000 to 2 seconds in 1 stop increments. The results were a little surprising.

• 1/2000 (+0) was black. Pixels ranged from 0,0,0 to 1,1,1 in value. Down in the noise.
• +1 stop had some value (up to 2,2,2) but nothing I'd call texture. Noise.
• +2 stops started to show real texture. Call this the beginning of the dynamic range.
• +3 - +10 showed texture.
• At 1 second and beyond (+11 stops), the image was maxed at 255,255,255. Beyond the range.

At ISO 100, this camera has a usable dynamic range of eight stops. So it behaves more or less (slightly more) like a color negative film camera. Nice!

Something else that can be had from a test like this is the response curve of the detector. So starting at 1/2000, I took the central 1000x1000 patch of image and looked at the mean value of intensity for the whole patch:

+0 0.41
+1 1.42
+2 3.68
+3 9.60
+4 20.38
+5 39.97
+6 72.46
+7 112.97
+8 154.53
+9 209.67
+10 248.84
+11 255.00

Keep in mind that each additional stop of exposure value should double the amount of light hitting the detector. Given that, you can see my camera is not the most linear thing in the world. So if you're using a digital camera as a quantitative photometric device, be forewarned! These things may not be linear! If in doubt, test your gear.

Armed with this information and a spot meter (which the A650 IS has, thank goodness) I can start making better decisions about metering and exposure. My A650 will never replace my monorail, but that doesn't mean I can't apply the same care and attention to detail when using it.

Tom

Further Adventures With Cameras

I finally did get out and do some shooting today, though it didn't work out nearly the way I'd intended. I left my rokkaku at home, and of course the wind was strong enough to fly the Flowform 16, but not strong enough for it to fly my camera. Which turned out to be just as well since all my rig "improvements" made it so the shutter wouldn't fire. Ah well, that's progress for you.

Instead, I spent some time messing with CHDK scripts, and got my camera set up to do five image bracketing, saving in RAW format. Yes, I'm trying to do HDR from the air. Of course without the ability to trip the shutter remotely, it was all moot.

So I did some HDR shots from the ground. Being near the ocean, of course I wound up with surf in the pictures. This didn't work out so well. The surf was different in each of the shots, so it didn't really work out well. So I did some inland shots, which came out better. Boring, but better. Then it hit me: Infrared!

I popped on my R72 filter and did a five shot sequence of the surf. The long exposure times blurred the surf into oblivion, so the stack worked. Also, I found out that algae, just like tree leaves, comes out white in the near-IR. I should've known this, but it really didn't occur to me until I saw it. Coolio!



None of the pictures I took are worth posting, being experiments rather than really carefully crafted shots. My "tripod" was three chunks of coral rock set in a pile with my camera balanced on them. Not the best thing in the world for framing a shot. But it shows I can shoot RAW with my camera, I can automate an HDR stack using CHDK, and the idea works well enough that I can do it in the infrared as well. More testing required!

Now all I need to do is un-fix my rig to the point where the shutter fires again. Sheesh!

Tom

Expert Amateurs

I haven't been doing photography lately because I've been heavily engaged at work. Which is typically not a bad thing for me. Even so, this last week has been rough. We've been coating a 4m class telescope mirror; a process that takes three days when things are really clicking, and longer if they aren't. This one took three very full days. I left the house at 5:30am each morning, and typically got home after 9pm each evening. Added to that, all the work happened at 14,000' above sea level. It takes a toll on a body. Trust me.

By the end of a schedule like that, everyone is tired, a little loopy, and ready for the whole thing to be over. The catch is this: not every coating comes off first-try. Any contamination, even the size of a fingerprint, can cost an entire coating. What's worse, you never know until the whole process is done and you take the mirror back out of the vacuum chamber. At that point you get to find out if you go home and wake up to a new day the next day, or whether you go home knowing you'll be waking up the next morning to strip the bad coating off, re-prep the equipment, order new chemicals, and start over. It takes a toll on a body. Trust me.

As the chamber was pumping down, an odd thought occurred to me: Here was a whole team of experts in our field, but mirror coatings happen so infrequently, in essence we were all amateurs. What's worse, practically every monolithic professional telescope mirror is coated by amateurs. There's really no escaping it.

Most professional telescope mirrors are coated with bare aluminum. Since telescopes are used outside by definition, they're exposed to the elements. Wind, dust, fog, and rain (yes, even rain...) slowly destroy the coating, so most mirror coatings only last three to five years. Then they must be stripped and replaced. For a telescope with a monolithic mirror this typically means the whole place is shut down once every three to five years so the telescope can be taken apart, and the mirror removed for re-coating. It doesn't make sense to have people on-staff solely to coat mirrors, so this usually means engineers and technicians who are otherwise occupied 99% of the time will be the ones doing the job. A job they have to re-learn every three to five years.

Yeah...

The place where I work is in a unique position. We're one of the older 4m class telescopes, so as newer ones were built in the same area, they had the option not to include coating equipment at their facility and to use ours instead. Several of them took this route, so we coordinate coatings for a number of telescopes. Running the numbers, we do about one major coating every year or so. This doesn't happen like clock-work, so some years we'll do two in a given year, and at other times we won't do any for years at a stretch. We've got more experience coating mirrors than most of the people in the area, but even so it's something we re-learn each time.

This past year we've spent weeks running experiment after experiment, trying to refine our technique: what chemicals we use, how we perform each step, which steps to include, etc. We're trying to make the process safer for the people involved and for the environment, and at the same time we're trying to build in as much assurance as we can that the process will produce a good coating every time. Leading up to this coating we had done dozens of small mirrors. If you needed to find someone with practice and experience, we were it.

Even so, there's a huge difference between coating a 12" mirror and coating a mirror more than ten feet across. The last one we'd done that size was our own, a year ago. Experts? Yes. But expert amateurs nonetheless.

We still don't know how this one turned out. The thickness was good, and the metal stuck to the glass quite well. But there's a blemish in the coating roughly half a meter square. We won't know how this affects the performance of the mirror until next week, when we can measure reflectivity and scatter in that area. At that point the people responsible for the mirror will make the call: Keep it as-is, or do it again and hope it comes out better next time and not worse.

Which brings up the reason we're all fine remaining amateur experts: Getting in more coatings per year typically means coating the same mirror twice. Coating the same mirror twice means things didn't work out right the first time. If that's the only way to become an expert, it's not worth it.

Tom

A Real Treat

I splurged.

I've been using a Tiffen circular polarizer since 1995, when my wife and I got our first 35mm camera. It's been great to have, and I've since claimed it for use with my KAP rig. But I knew it couldn't last. My wife has given me more than one subtle hint about the lack of a CP filter in the DSLR bag, and the thing is beginning to show signs of wear.

So I put in a bid on a new Hoya SuperHMC circular polarizer. It's $20 under list, so I hope I get it. I'd prefer a Heliopan, but the $130 price tag is half what I paid for my camera. It's too rich for my blood. But the Hoya has had good reviews, and it's going to be worlds better than the Tiffen I've been using so far.

But why stop when you're on a roll?

I also went to Jones Airfoil and ordered a KAP Feather, which is one of the more ingenious stabilization devices I've seen for KAP rigs. I plan to use mine on my digital rig, but I'd like to consider it for my 4x5 rig as well. They make a larger one for DSLR rigs that should be a good weight and cross-sectional match to the 4x5. I can't wait!

Sure, it's a splurge. But it's not without purpose. These two additions to my KAP bag should let me take better pictures. Less lens flare, less motion blur, it's a move in the right direction.

Tom

Lens Flare is Lame

It's funny how the mind can forget things. All the years I've done ground photography, lens flare has always been a consideration. With large format photography, especially, I've always been conscious of where the sun is, whether it can shine on my lens, and how I can keep that from happening.

So why I forgot all that when I hung my camera on my kite line yesterday, I'll never know. Granted, I was shooting outside my comfort zone. But photography is photography. The location of the camera doesn't change that.

Most of my KAP has been done near noon. This isn't a conscious choice of time or light, it's simply when I get to fly. It's not the best time of day to be doing photography, but it does simplify a number of decisions. Exposure is almost always sunny-16, and when I use a polarizer I always know where the sun is, so I can use a fixed rotation.

Yesterday I shot in late afternoon light over water with a partly-cloudy sky. I opted not to use the polarizer for fear of cutting out too much light. I also opted to put a UV blocking filter on the end of my camera's lens barrel to try to keep stray sea spray and sand from hitting my optics. The combination was disastrous. Every shot came out with lens flare, blown out skies, washed out mid-tones, and every other sin of the inexperienced photographer.

Gaaah!

Today, instead of rushing out to correct my mistake, I decided to spend a little time taking care of my long list of nagging complaints with my rig, and to try to think through ways to keep from repeating my experience of yesterday.

For starters I took the filter adapter barrel off my camera and spray painted the inside with flat black paint. Why anyone would make a piece of optical equipment with bright, shiny surfaces near an optical path, I have no idea. But that's what they did. Now my adapter barrel is fairly un-reflective on the inside.

Next, I took care of some issues that have been bugging me for a while. My 1/4-20 mounting screw is now tethered to my rig. No more dropping my mounting screw into loose a`a lava, only to see it disappear into the rock pile! Likewise I cleaned up my shutter servo mount, simultaneously making for better alignment with the shutter button and shaving off a little weight. Finally, I slotted the mounting hole for my camera, so I can get it a little more snug against the bracket. No more wobbly camera!

But back to the lens flare, what I really need is a way to get a large(ish) lens hood on my camera. The problem is everything that goes on my KAP rig can act like a sail and catch the wind. A lens hood is essentially a giant sail, mounted far out from the axis of rotation. It's going to cause instabilities in the rig!

So for now I don't really have a good solution on lens flare except to fly with no filter and hope. Meanwhile I've taken the UV filter out of my bag, leaving only the polarizer and the Hoya R72 IR filter I use for ground photography.

But the rig is looking a lot better. I hope I can get out this afternoon and give it another go.

Tom

My Dear Old Jeep

It may finally be time to trade in my dear old Jeep for something different. It's not just the oil crunch, though I'd be lying if I said that didn't have a bearing on this decision. It's also not the fact that I have an oil leak under the valve cover. That's about as fixable as an oil leak gets. It might have something to do with the smoke coming out of my valve cover that leads me to believe one of my valve seals is going. But the biggest bugaboo for me is that the cabin fills with exhaust gases if I drive for any appreciable distance.

Yeah...

I did about 100 miles today running errands, never got a camera out, never got a kite up, and wound up with all the classic signs of carbon monoxide poisoning. Exhaust leak? You bet! Do I want to do this again? HECK NO! So now I have the choice: Fix the exhaust leak, replace the valve cover gasket, potentially rebuild the head, and continue to deal with lousy gas mileage...

Or...

I need to start looking at the classifieds, Craig's List, and just checking out the side of the road. Most cars here sell by word of mouth. Once upon a time everyone parked their used cars at the city park. I think they started cracking down on that, though, because a few years ago people stopped. For a while the unofficial used lot was the lawn in front of the place where I work. But even that seems to be losing favor. The last time I saw used cars they were down by a horse pasture near the transfer station. Keeping my eyes peeled!

So what am I after? I'd LOVE to have the Professor's Delorian from the end of Back to the Future. Mr. Fusion, here we come! But since I'm a practical person, I acknowledge that the chances of that happening any time soon are slim to none. Sooo...

Four doors would be great, but not necessary. Off-road would be terrific, but considering that's where my Jeep loses most of its gas mileage, I'll part with this one. >30 MPG would be fantastic, but for used I'd take >25. I'd like an engine I don't have to mess with, a suspension that just plain works, and brakes that can take whatever I dish out without needing constant rebuilding. I'd like enough trunk space to fit a quarter sheet of plywood along with all my KAP gear.

And #1 on my wish list? Air conditioning.

Most of the time I don't need it and wouldn't use it. But driving to Kona really hammers home the utility of something that keeps you from boiling in your own juices.

Right now, though, I'm facing the certainty that I'll be driving my CO-filling Jeep for a few more months. Windows down!

Tom

Twice Bitten Once Shy

Or so the saying doesn't go. But it's how it happened, anyway.

Friday night my wife and I went to bed, read for a while, and turned off the lights. The only unusual difference was that instead of sleeping with a pillow over my eyes like I normally do, I put it down at my side. Insignificant at best, but it became important later on.

I was right on the edge of sleep when I realized I was uncomfortable. So I rolled over on my side. Our roadside-rescue kitten, Storm, was sleeping between us. Storm is still in the process of being de-fleaed, so I had reason to suspect I was getting flea-bit. Grrrr!

Shortly after rolling over, I felt like I was being bitten. Fleas... GRRRRR! I reached over my shoulder to flick off the "flea" and ran into something largeish. Funny how fast you can go from sleepy to wakey when something like that happens!

One of our cats, Nala, is in the habit of bringing play things into the house. Mice, grasshoppers, moths, mice, oh, and mice. @#$%???!!! What bit me?! Was it one of her presents?!

Apparently at this point I was still utterly incoherent. My wife later told me I said words to the effect of, "I just got bit by something, and it took a chunk out of me!" Not being incoherent, and being pretty sensible about such things, she sat stock still and said, "Turn on the lights. Now."

Lights on, nothing there. So I started pulling my pillows out of the bed. It came as no surprise to her, though it utterly shocked the bejiminies out of me, but an eight inch centipede dropped out from under one of my pillows and flopped onto the bed, only to scurry off and disappear somewhere.

Insignificant as it may have seemed, at this point I should've been really really glad I didn't sleep with my pillow over my eyes! That thought didn't occur to me until much later, though.

My wife checked me for bites. She found two. One was bad enough to draw blood, and the fang-to-fang separation was on the order of 8-10mm. It was a big 'un. The other bite didn't have clear fang marks, but it was already turning red. Pretty soon my whole shoulder/neck area was inflamed.

If you've never been bitten by a centipede, by all means keep it that way! Don't start now! But if you have, you probably have some idea of what I was going through. It feels like someone squirted lighter fluid all over you and lit it. And from what I've heard there's really not much you can do to cut the pain except ride it out. So I got busy with that while we tried to figure out where to sleep for the rest of the night. It was still in our room, for crying out loud!

At this point another worry started to nag at me: I'm allergic to bee and wasp stings. So far I haven't had respiratory failure because of it, but in high school I had skin reactions to a sting that convinced my mother to take me to an emergency room. This was way worse than any wasp sting I'd ever had! I told my wife to keep tabs on me in case I had trouble breathing or anything.
Luckily my wife knows her exoskeletal life forms better than I do. "It's not an insect. The toxins aren't related." What?! "Centipedes are arachnids, not insects. You get a histamine reaction to insect stings, but arachnid venom is a neurotoxin. I'll keep an eye on you, but I don't think you have anything to worry about."

A rational person would've believed a rational voice like that. But I still felt like I was being burned alive from the shoulders up, and it was starting to feel like things were moving around under my skin, from my neck all the way down to my left hand. I don't have anything to worry about?!

In the end, of course, she was right. We did finally drop off hours later, sleeping on our futon couch. In the morning I still felt awful, but it was better. It just felt like a really bad sun burn. By the end of the day things were back to normal, and I couldn't even tell where the bites were.

But I'm never forgetting what it felt like. Never again. Not if I can help it, anyway.

Tom

Coming Home Empty

I managed to get out both days this weekend. Saturday, my son and I went to Kua Bay, the place with the consistent wind. Only it wasn't consistent, and for the most part it wasn't there. I didn't even get a kite up until after 11am, and that was iffy at best. I posted some stuff to Flickr and Facebook, but nothing I'd frame and stick on the wall.

Nevertheless, it was fun. I hadn't flown my digital KAP rig in over a month, and it was nice to get everything out, get it all airborne, and take some pictures. But it did hammer home the need for some new places to fly. Cruising the KAP group on Flickr helped, but so many of the places other people are flying simply don't exist here. Scott Dunn did some fantastic urban KAP in NYC, Fanny and Anthony flew at an abbey in France (with permission!), and strange though this may sound, Craig Wilson did some really cool architectural abstracts at a sewage treatment plant. Outstanding photography of subjects that simply don't exist here, darn it!

Sunday I threw everything into the car, and we went for a hike at Pololu Valley. The wind didn't feel right, and I found I'd thrown everything but my rokkaku into the car. There's not enough beach in Pololu to fly the Flowform, so basically I'd shot my KAP efforts in the foot. But a quick rain shower convinced me that was no bad thing. I grabbed my 4x5 bag and tripod, and hit the trail with the rest of my family.

Here's why I don't like switching film on my 4x5. I'm used to shooting one B&W film and maybe one color film, if I felt rich enough to buy a box. Without a color lab on island that'll touch large format film, I've mostly stopped shooting color. I've grown complacent. I expect to have only one kind of film in my bag now.

OOPS!

My first two shots were done on what I thought was 400TMY, but I later found was 100TMX. My third and final shot was on 400TMY, and I'm not convinced it was worth tripping the shutter.

So now I've got a developing nightmare, with four 100TMX shots from several weeks ago, all shot at ISO 100, two 100TMX shots shot at ISO 400, and one 400TMY shot, shot at ISO 400. Three different development times, three times as much time in the darkroom.

ARGH!

But the best part was coming home all disappointed and discouraged, and seeing a new post in Scott Bulger's Blog about not being greedy, and not tripping the shutter unless you've really thought out your shot. It's well worth the read. And for me it was the difference between disappointment in a day's non-photography, and feeling like I did the right thing by not taking pictures.

So I came home empty. But looking back on it, I really did have a good time getting there.

Tom

More 4x5 KAP Updates

I think my 4x5 KAP camera is getting close to its final form. There are only a few tweaks left, and most of them are minor. Back in April I'd posted a tick-list of items to address. Here's how they stand:

• Test the lens against a USAF resolution target: Done. f/16-f/22 is the sweet spot.
• Chrono the shutter: Done. I'm a full stop off at every setting. Lens needs a CLA.
• Replace eyebolts in the Picavet with pulleys: Done. I need to modify the pulley blocks, but the new Picavet works GREAT.
• Replace the Picavet with a Gent-X geometry: Done. But the wide arm is still too wide. Cut down the 12" x 4" cross to a 10" x 4" cross.
• Positive locking on all pivot axes: Mostly done. I don't like the thumb screws on the tilt axis, but they work.
• Add new holes to allow for plan rotation: NOT DONE.
• Light trap for the exposed edge of the film holder: Done. Works like a champ.

So really the only thing left is the extra set of mounting holes to allow for plan rotation. This is a must, and has not even been started. Meanwhile, here's how things look now:

The light trap covers the exposed edge of the film holder, and keeps stray light from entering through the dark slide trap. Most of my film holders are ok, but at least one has a slight leak. No biggie on the ground, but in the air where the sun's shining on the back of the camera all day, it's an issue. No more!

The vertical sight guide makes placing the horizon in the shot very straightforward. There are lines for 1/3 points in the frame, as well as a line for the center and outer edges of the frame. In tests it looks like a well-balanced Picavet can hit the horizon to within a few degrees.

The horizontal sight guide works similarly, and lets you place the scene on the frame. There's a second one on the bottom of the camera, so with the kite line tethered you can walk out and double-check the camera is pointing the right way.

For the moment the success of this is a little hit-and-miss. The camera likes to weathervane in the wind, and in my test flights it would tick-tock between pointing where the line wanted to point it (line tension high) to where the wind wanted to blow the kite (line tension low). This is exacerbated by the wind here, which changes compass heading depending on altitude. The kite and the camera rarely want to point in the same direction. I need to fix this with some sort of vane system like a KAPFeather or something similar.


Unfortunately the biggest change of all really can't be seen in a photograph. I changed films. Up until now I've been using Kodak 100TMX, the ISO 100 TMax film. I switched to 400TMY-2, the reformulated ISO 400 TMax film. This bought two stops of light, and the film has almost the same sharpness and resolution as 100TMX. Since I use this camera under Sunny-16 conditions, this meant I got to shoot at 1/250, f/22, right in the lens's sweet spot. The results speak for themselves:

But the results also point out another change I need to make to the camera:

I need a filter holder! A fellow KAPer from France pointed out that I could get a lot more differentiation between the water and the land if I'd put a blue filter in front of the lens. I can't really do that since my B&W filters are all Wratten gels, and the wind would wreak havoc on them. But an internal filter holder for Wratten gels is entirely doable, and wouldn't present any more surface area for the wind.


All in all I'm still very very pleased. My list of things to do isn't empty, but it's a lot shorter. And the new things I'm coming up with are niceties, not show-stoppers. The camera itself is ready for regular use now. Next time I go out to do KAP, it's coming with me.

So what's next? Two new cameras are starting to take shape in the design department. The first is a 35mm spin panorama camera. The second? A medium format multi-shot film camera designed specifically for KAP.

Tom

A Really Nice Break

I took a vacation. Strange, but true! We threw our stuff in the car, rented a cabin at Volcanoes National Park, and moved in for six days. No cell phone, no email, no computer, no nuthin'.

It was GREAT!

I packed my KAP bag, but except for using my camera, the rest of the gear went almost entirely unused. Volcanoes National Park doesn't allow kite flying inside its borders, so I never got to do KAP while we were there. We drove down to Kapoho to swim in one of the hot pools there, but I didn't fly there, either. Because of space constraints I also couldn't bring my Bender 4x5 camera, either. Photographically it was an odd trip. I wound up using my A650 almost exclusively. A far cry from my normal monorail-toting, KAP-flying, gear-heavy self. At one point I even figured this out, and quit carrying the KAP gear with me. I stuffed a little camera in my jacket pocket, grabbed my tripod, and went a' walkin'.

The view of the eruption in Halema`uma`u was outstanding. The only other time I'd gone to the park to see it, the wind was iffy and the gases were collecting at the crater. It made for muddy pictures and burning eyes. Not this time! The weather was unbelievable.

Some of the trails were closed, like the trail across Kilauea Crater, which I've done with the kids numerous times. Still, Kilauea Iki was open and we spent several hours down there doing photography. My older daughter inherited my old KAP camera, a Nikon Coolpix 5600. She's developing a good eye, and in time is going to become a really good photographer. My son's camera really isn't made for this kind of thing, so my wife and I gave him our Coolpix 950, our first digital camera. It's dinky by modern standards, but it was built early on in the age of the digital camera when people thought they should be built like tanks. Perfect! We had a blast, and while they were busy doing their thing I was able to re-visit shots I'd attempted before. The fern shot is one I'd attempted, and failed at, a number of times. This time it worked.

We went on a new trail this time, Kipuka Puaulu. It was beautiful. Kipukas are forested cinder cones that get cut off by a subsequent lava flow. This isolates the flora on the cinder cone, making for a really neat natural biological laboratory. Kipuka forests tend to be interesting places to visit because they essentially become self-sufficient environments. Animals and insects can move in and out, but the plants tend to be stuck at that point. Kipuka Puaulu has a nice mix of koa, ohia, and other trees, along with tree ferns, flowers, and all sorts of other stuff. Great place to go if you're in the park.

It was my first time playing with IR in the park. The Canon A650 IS isn't the best camera for IR, but it's workable if the wind isn't blowing too hard and the vegetation is mostly sitting still. Because of the contrast between vegetation and fresh lava, it made for some interesting views. In the end it helped make the fern shot work because the vegetation tends to blend in with the rock when shot in visible light. In the IR it worked.

We came back bruised, cut, a little beat up, and utterly exhausted. Just the way a vacation should be! Can't wait for the next one.

Tom

Light at the End of the Tunnel

One more weekend without even pulling out a camera: a photographic dry well. I did get my kite up at Mahukona, but the offshore wind was so shifty, it wasn't worth risking total loss of my gear. So the kite came right back down, the KAP bag went right back in my Jeep, and we went right on our merry way.

Earlier that day I stopped at a place I've heard described as "Whistling Canyon". In reality it's a gulch, eroded out by water flowing off of Kohala. But the shape is closer to a box canyon, so the naming makes sense. The canyon faces 90 degrees to the Tradewinds, and it really does whistle. The disconcerting part was the edge, which is completely vertical. I've grown used to tall cliffs, but usually they have some sort of slope on them, often with trees. If you fall it'll hurt, and it'll hurt bad, but there's at least a 1% chance of survival. At Whistling Canyon, the cliff face is vertical rock. There's nothing to stop you for several hundred feet. I was more cautious than usual. It was a great view, but in the end I couldn't work out any good angles, but I plan to go back when the water's flowing to see if there's a way to get in front of the waterfall. That would be pretty.

Toward the end of the weekend I remembered I had four sheets of TMX from a previous shoot. DOH! I didn't get around to developing them, but I hope to get those done tonight. In the meanwhile I found some stuff in town to photograph, so I'm planning to spend my lunch hour walking around with my 4x5 and my last sheets of TMX. With any luck I'll have at least six sheets to develop tonight, and some empty film holders to load up.

Next week I'll be spending a fair bit of time on the other side of the island, doing photography among other things. Since the 4x5 KAP camera clearly needed something faster than TMX which is an ISO 100 film, I ordered a box of improved TMY. It's an ISO 400 film with better grain structure than the older TMY formula, and only slightly less sharpness than TMX. Perfect for aerial 4x5, and it can't hurt on the ground, either. Since I can't image the grain on my TMX negatives with the scanner I'm using, I'm not taking much of a hit in order to get two stops improvement in speed.

In order to make the aerial 4x5 work I also need to rebuild the shutter on my 150mm lens. I've got some good instructions on how to do this, but it'll be my first time. All the symptoms point toward a dirty clockwork mechanism. This makes sense considering that shutter had its flash sync socket ripped out at some point in the past, so dust and other contaminants can get inside. I'll be fixing the hole in the side of the shutter as part of the repair, so hopefully this won't happen again.

Lots to prepare before I can go, but I'm looking forward to the trip. There hasn't been this much photographic possibility in front of me in ages. It's the light at the end of the tunnel.

Tom

A Flickr Group Search

A few days ago I was chatting with someone online, and they kept going idle. I finally asked what they were up to. "I'm doing a Flickr group search," they said. Which of course begged the question, "What's the search?" But like any online search, the answer is always too nebulous to describe. One thing leads to another, leads to another, leads to... well... that's interesting!

For some reason today I got to thinking about Lowell Handler's book, Twitch and Shout. I read it ages ago, right after being diagnosed with TS, myself. I won't go into my feelings about Mr. Handler or his writing, but one thing that did strike me is that he was able to capture, in still photographs, the dynamic nature of TS through a series of self-portraits.

Hey! TS photography!

The next logical step, of course, was to do a Flickr group search of my own. I tried "Tourette", "TS", and a whole host of others. No dice. The closest I came were discussions where people used the term, typically not in a very representative way. (Typical.) So I broadened the search and found a number of groups with an OCD bent.

Two, in particular, caught my eye. The first, OCD, is for photographs that express OCD, or were taken as part of an OCD compulsion. Fascinating! A number of the pictures really resonated with me. Some I couldn't look at because they were too close to intrusive thoughts I've had in the past. Some were just downright disturbing. But I'm not one to judge. I'd hate to see some of my intrusive thoughts in photographic form, posted on the web for all to see. And I'm guessing that's what some of the images were: externalization of intrusive thoughts.

The second group illustrated a problem that one of the discussions in the first group touched on: Just as TS is often brutally mis-portrayed, so is OCD. The second group, Organized OCD Style, opens its description with:

"Are you OCD or a wanabe OCD? Are you super organized and super clean?"

Setting aside my feelings about the first sentence, the second sentence is just plain wrong. Being super organized and super clean is more of an indicator for obsessive personality disorder than it is for obsessive compulsive disorder. One could argue for colloquial use of the term, but in reality all it's doing is spreading misconception about what OCD actually is. I wish people would do a little reading before using a term like that in an off-hand, and consequently incorrect fashion.

But I digress...

In the end I wound up shelving my searches and asking myself this question instead: Does having TS or OCD really have any affect my photography? I have to think the answer is no.

I don't think I go through any compulsive rituals when I do photography. Oh, there are the usual suspects like level horizons and gear checks, but that's to be expected. I don't know many photographers who don't sweat horizon lines at one point or another, and it's only natural to check your gear before heading off on an all-day hike, much less putting a camera up in the air.

As far as embracing either as a source of inspiration for photography, I really haven't. Years ago I tried to do something similar to Lowell Handler's self-portraits, but I have far fewer facial tics and the results were pretty lackluster. And I have no interest whatsoever in externalizing the intrusive thoughts I have. They're disturbing enough when left inside!

No, for the most part I do landscapes. Aerials, infrareds, panoramas, black and white, color, film, digital, I really don't discriminate. I just like to do landscapes.

So what Flickr group should I search for that would be just right for me?

"We found 27,111 groups about 'landscape'."

Oh dear...

Maybe I should just stick with the groups I'm already in. Better yet, I should turn off my computer, grab my camera, and head out the door.

Tom

Repacking and New Gear

Since replacing my KAP backpack with a new one, and after a few long-distance hikes, I've decided it's time for a new winder that fits better in the pack and does a better job of what I want.





This winder design is based off of one that's apparently heavily used in Germany and most of Europe. I got my basic design from Erick, a fellow KAPer. This is my fourth or fifth revision of his design.

I want to be able to carry 500' of #200 and #100 Dacron line. Right now I carry two separate spools of 1000' of each. Since I never let out more than 500', I'm carrying unnecessary weight. Also, only one winder fits in my pack. I typically carry the other one in my hand (awkward, to say the least!) This lets me carry two weights of line in less space.

The center handle is an inline skate wheel. I took one from my scrap bin. With my fist wrapped around it, my entire hand-size is just over 5.5" in diameter. That's a 6.5" diameter ID on the side plates, so my hand should fit fine.

My earlier designs had winding handles on both sides, an idea Erick, among others, didn't much approve of. Since using an extension cord winder as my kite line winder for over a year now, I have to agree. As long as the center handle is placed pretty close to the mid-point of the winder's thickness so the forces all line up, you only really need a winding handle on one side.

In this drawing the winding handle is a second inline skate wheel (though it's hard to see, tucked on the bottom as it is.) In the final build I'm more likely to make a 1.5" diameter Delrin knob, and press the bearings in. It'll be more compact that way. The winding knob will be removable so the whole winder sits flat for packing into my backpack.

I already use the center of my current winder for storing my two 3m lengths of fuzzy tail. This cavity is actually larger, despite the handle in the middle, so it should still be able to fit the two lengths of tail, and might be able to hold my ground strap as well.

The side plates, as designed, are 1/4" and 1/2" plywood. If the outer 1/4" plywood is not sufficiently strong, I can swap it out for a 1/2" plate. Either that or reinforce it with fiberglass cloth. (I'd rather not go that route.) In any case the wood will be painted and sanded before assembly.

The spacing between the plates will be tuned by changing the lengths of the spacers on the twelve bolts. I only want 500' of each kind of line, so I can tune the length of the spacers to make things fit juuuust right. Right now my winders are 3.75" tall. I'm hoping to get this to be slightly flatter, but I won't know for sure until I wind on the line.

The holes around the periphery of the plates is so that the line can be clipped off at a given length using a carabiner. This is the technique I use on my current winder, and it works great. The holes also cut down on weight, though the amount is negligible, when you get right down to it.

The twelve bolts that hold the whole thing together are drawn as button head cap screws. I'll probably swap those out for flat head screws in the final build so the two side plates will be completely flat. I'm accident prone enough as it is. Anything that could be described as a "knuckle buster" will probably be closer to "finger remover" for me. Safety first!

I'm also going through my backpack to remove as much weight as I possibly can. One change I need to make, given that I'm doing more KAP hiking these days, is to get all my chargers and store them in a separate bag I can leave in the car. It really makes no sense to carry around a bunch of charging gear when the nearest source of power is back in my Jeep! There's a lot of room for improvements in this area. I can probably shave several pounds without much effort.

It'll be a good change. And cleaning out my pack will make hiking a lot easier.

Tom

Dry Spell

It's not for lack of trying, but I hit a bit of a dry spell.

Friday I went out with a bunch of friends, and we went down Mana Road, a dirt road that runs from Mauna Kea back into Waimea, across the Mana Plain. It's beautiful, it's photogenic, it even goes through a koa forest. Despite doing enough photography to get a sun burn, and having my Chicken Little antenna ball eaten off by horses, I came home with almost no shots to show for it. I even managed to drop my radio and bend my antenna. I have a new one on order.





(Though I do still have one I need to work on. It might be the one real keeper from the weekend...)

The next day my son and I set out to go through a big lava tube near Kona, but we got sidetracked by Kiholo Bay and Wainanali`i Pond. It was gorgeous, and I did get several pictures of my son, but the wind was dismal. Despite flying a kite all the way back to the car, I only hooked my camera up once and almost crash-landed it. By the time we got back to the car my son was dehydrated and overheating. We passed on the lava tube and ate lunch somewhere with air conditioning and cold drinks. And salty food. And comfortable seats. Egads we were both messed up. (We went back to the lava tube in the afternoon.)

The winds died down and the house is socked in with volcanic gases again. It's about as photogenic as an exhaust pipe. The winds tomorrow look about as dismal, with VOG blowing in to town through two separate pathways. Nowhere to run to, nowhere to hide and do photography.

During the Mana Road trip, I got to talking with one of my friends who's a fellow photographer. Getting a good weekend of shooting is like getting a fix, he said. Having material to play with for the rest of the week is wonderful. Coming up dry? Nothing worse.

I have one shot I need to work on, and no prospects of getting more tomorrow. I'm sunburned, frustrated, and stuck in a dry spell.

Tom

Digital Image Noise Reduction - Take Two

In an earlier post I talked about infrared imaging with the Canon A650 IS, and also discussed noise reduction in a digital image through image stacking. Unfortunately I wasn't all that careful with my technique, and as one reader rightly pointed out, the stacked image was blurrier than the original I used for the side-by-side.

In a word: DOH!

So I set up the test again. This time I skipped the whole infrared thing since to some extent it only confuses the issue. This technique should work on visible light images, too. I also skipped the whole black and white thing since this should work on color images as well as it works on B&W ones. I also skipped hand-holding the camera since I had my tripod with me this time!

So without further ado, here's the second attempt at image stacking to improve noise characteristics in an image...

I started with a pretty bland setup in my kitchen: Two cutting boards, one mug (I know... it's dirty), one magnet, one tea ball, and an index card. With my camera mounted firmly to a tripod, and with a self-timer and intervalometer all set up, I took ten "identical" images. Each was shot at something like f/4.6 for 2 seconds at ISO 80. By default the A650 IS also subtracts a dark image from any image longer than 1 second, so thermal noise should largely be removed. Readout noise is pretty minimal for this camera, so most of what's left is photon noise.

A quick note: All the photographs in this article are clickable, and all of them were uploaded to Flickr at full resolution. For the full image shots, that's 4000x3000, so you have to view them at original size in order to see the noise. For the side-by-side shots that's 2000x1000, so you still have to view them at original size to see the noise. Have fun!





That's the final image in the sequence of ten. Except for the utter blandness of the shot, it looks pretty good! Aaaaah, but if you look closely in the shadows, in the smooth areas of white, and around highlights on the metal bits, it's pretty clear there's a fair bit of noise.

So what happens if you stack ten separate images of the same scene? Turns out, something pretty neat:





Same scene, same lighting, same everything. But the noise is reduced by a lot. Still, there's nothing like a side-by-side to compare.

In this first one, take a look at the index card and at the white parts of the mug. The last image from the sequence is on the left, and the stacked image is on the right. The difference in noise level is pretty striking. Also take a look at the silk screen pattern on the mug handle. (Ignore the break in the printing... I didn't print it.) The pattern isn't muddied at all by this technique.





In this second one, take a look at the noise in the wood grain and in the reflections on the magnet. There is a fingerprint on the magnet, which is preserved in both shots. Again, the difference is pretty striking.





In this last one, again look at the white areas on the mug and the index card. There's still a fair bit of texture on the index card in the stacked image. But if you look closely you can see it's just the normal surface texture of an index card, pretty accurately rendered. Almost all the photographic noise is gone. Also, the silk screen pattern is clearly not muddied by this process.





So it really does work! And it works even better if the photographer doing it is a little more careful about technique, and doesn't use fuzzy images in the stack. (DOH!)

What's more, the resulting image will have a lot more information in it than any of the originals. A normal JPG image has 8-bits per pixel for a max value of 256 per color per pixel. I used ten images in this stack, so my max value is 2560 per color per pixel. That's roughly 11 bits of information. Lots of room for gamma correction and filtering without introducing artifacts!

One last note before I leave this topic: This is not HDR. The images were all taken using the same settings. Also, I used JPG images rather than RAW. No reason not to use RAW, but there's no need to, either. Any camera can do this. Any photographer can do this. I'm not sure every photographer would want to, but they could if noise was an issue for them.

Tom

Varying Tastes (or... The Oddness of Explore)

An important point for any photographer to remember is that you really can't predict what other people will like. The only thing you have any say in is what you like. I often lose sight of this as I post pictures on Flickr, Etsy, and Zazzle. I post what I like, then I get surprised, and yeah, sometimes hurt, when other people don't share my viewpoint.

I recently discovered a tool that's apparently been around for a long time: Big Huge Labs's Flickr DNA will give you a nice graphical look at what your pictures are doing on Flickr. Which ones are popular, which ones are new, how many, who looks at them, etc. It also tells you which of your pictures have been featured on Explore.

I don't use Explore, so I wasn't even aware that three of my pictures had been there. They don't send you email or give you notice. Your picture just starts getting these odd hits. One picture I wasn't really all that fond of was one of the pictures that had been on Explore. So I asked my wife what was up with that. "I like it!" she told me. Oh...





This recent hike I took is another good example. This morning I checked for comments, and found a whole slew of comments and favorites on Flying in a Blue Dream (the two swimming honu picutre from my previous post.) Sure 'nuff, it was featured on Explore.

The funny thing is, from that whole set my favorite is the Golden Pools vertical panorama. It was technically challenging, done on purpose, and had what I thought was a really neat set of colors as you move from bottom to top. The honu picture was serendipitous! Utterly unplanned! And cropping it was a bit of a nightmare because it wasn't even composed that way on purpose. (I didn't know the honu was there!)

And yet...

I've wondered this before, and wonder about it even more now: As photographers, I think we get our heads wrapped around an idea, and when we're culling the shots we took that day, we're doing it with that idea firmly in mind. If a picture doesn't fit the mental model, it gets chucked even if it's a perfectly good photograph! I know I do it. I'm guessing others do, too.

So what if a bunch of photographers went out on a shoot together, each with their own mental model of what they want from the day's work, and instead of editing their own photographs, they edit someone else's? Ideally, they'd rotate through everyone's shots, including their own, and put together their "take" on the day. At the end, all the photographers give slide shows to each other, pointing out what they did, why they did it, and whose work it was.

I'm wondering if they'd even use the same set of images!

Tom