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Archive for February, 2012

A Tiny, Weird World

Posted by Tom Benedict on 28/02/2012

I just ordered four lasers off of Ebay. One was a 5mwgreen laser pointer. The other three came as a matched set of laser pointers, one each in red, green, and blue. The sum total for this science fiction excursion? Less than thirty bucks.

I gotta shake my head…

Years ago I worked at a really cool place called the Center for Nonlinear Dynamics. For an undergraduate who was trying to scrape by and pay for his degree without having to take out a loan, it was heaven. I remember very clearly when one of the researchers brought in a paper to show us. I think it dealt with instabilities in laser cavities. But the real reason we were all geeking out on it was that the laser cavity had been created using photolithography. It was the first time any of us had seen something like that before: a laser diode.

The guy who was bringing this around was almost bug-eyed at the possibilities. “Do you realize what this means?” he asked with an edge in his voice. “Lasers are going to become affordable! Who KNOWS what we might do?”

I ran the computers at CNLD. One of my jobs was to do backups and perform OS upgrades on all the machines. The OS came on quarter inch tape. It took about six hours per machine to do the upgrade. Three years later when I left CNLD, I was doing upgrades using CDROM. Upgrades took less than an hour. It was a brave new world.

After lunch today, one of my co-workers came in with a problem: We have a cross-dispersed echelle spectrograph that images the entire visible spectrum in a single shot on a CCD. He’s working on some changes to the CCD code that could speed up our readout times. But there’s a risk of cross-talk between the outputs of the chip that would cause ghost images if any of the pixels saturate. Saturated pixels are almost a given with spectroscopy, so he needs to be able to see if this is a problem. One way to test it is to shine laser light into the spectrograph and see if we get one line and only one line, or one bright line and one dim line (the ghost). Easy enough to do, but what if the line doesn’t fall in the right place on the chip for testing?

As we knocked ideas around, we realized we could shine several colors of light into the spectrograph at the same time. Hey, cool! We have red HeNe lasers, and we’re pretty sure we have a green HeNe laser at our summit location. That’s two colors. But more would be better. What about a red laser pointer? Turns out they emit at a different wavelength than a red HeNe. So that’s three wavelengths. What else could we use?

I searched Ebay and found a green laser pointer that would compliment the red one we already have. Then I scrolled down and found the three color set. Five minutes later I had four lasers ordered. They should show up just in time for testing.

So the lasers came full circle, in a manner of speaking, from research lab to consumer product, and back to research lab. What could have been a fairly involved test using a monochromator and a good bit of optics was solved using some stuff picked up off Ebay for a couple of bucks. Can’t beat it.

– Tom

P.S. They even run on AAA batteries! Rechargeable lasers!

Posted in Engineering | Leave a Comment »

KAP Gone Wrong

Posted by Tom Benedict on 26/02/2012

Not every kite aerial photography session is a success. Some are less than satisfying. Some, outright failures. And others are disasters.

Today’s session was something between less than satisfying and a failure. After checking the Mauna Kea Soaring wind models I’d planned to fly just south of Mahukona at a historical site I’d flown at before. It’s a tough spot to fly because most of the time it’s downwind of Kohala Mountain. The rare days when the wind shows up, it’s because of a weather pattern that causes wind to follow the curve of the shoreline. Today was supposed to be one of those days.

It wasn’t. The wind was so flat, I didn’t even bother to stop. Sometimes the wind models are less than accurate. When that happens, I try to come up with an alternate flying location. The models said the wind at Kauhola Point would be in the 12-15kt range. Not my favorite, but not bad. I drove past Mahukona and kept going until the turn-off to Kauhola Point.

Things didn’t look right there, either. There was almost no motion in the large palm trees along the road. “Ok,” I thought, “The point is a good couple of miles from here, and can be in a different wind regime. Give it a chance!” I gave it a chance. But when I got there the wind was hardly blowing. I debated putting up the Dopero, but settled on a 7.5′ Rokkaku instead. The kite went up, the pull was just enough to lift the rig, and things looked pretty good.

Kauhola Point used to be the home to a pretty cool lighthouse that was built back in the mid 30’s. I photographed the old lighthouse during World Wide KAP Week 2009. At the time it was one of my favorite KAP images.

Kauhola Point Lighthouse

A year later the lighthouse was torn down because of the severe erosion of the coastline directly underneath the foundations.

Lighthouse from Up High

The Coast Guard removed every trace of the lighthouse as well as the old foundations for the generator and engine that used to power it. The lighthouse was replaced with a “monopole structure”, an increasingly common practice when older lighthouses are torn down. Prior to seeing the new lighthouse at Kauhola Point, the only experience I’d had with monopole structures was the lighthouse at Ka Lae at the south end of the Big Island.

South Point Lighthouse

The first time I went out to Kauhola Point after the new lighthouse went up was quite a shock! The new one was located farther inland to remove it from the eroding coastline. And it was tall! Far taller than the lighthouse at Ka Lae. But it was still a monopole. Deep down, I was disappointed. I think there’s value in old designs that more efficient stainless weldments just can’t match.

But a good kite flying spot is a good kite flying spot. I’ve returned to Kauhola Point several times since. The monopole is just as challenging to photograph as the old lighthouse, and I wanted to give it a try with the video down-link on my KAP rig. The light was wrong, but the wind appeared to be friendly.

Monopole Lighthouse II

The video down-link let me line up only two really good photos. This first one was nearly directly-down, and worked well straight off the camera. I could’ve wished for a little more room on the bottom, but all in all I’m pleased with how it turned out.

Monopole Structure I

The second was supposed to be half of a pair of photos for a diptych. I wanted one looking at the lighthouse facing toward shore, showing the vegetation at Kauhola Point, and a second looking at the lighthouse and facing offshore, showing the rough waters around the point. I only got the first half of the diptych done before things started to go bad.

As I walked the kite around for the second shot, I noticed it was flying to the left of downwind. Typically on a large kite like a Rokkaku, this means the kite is over-powering. Small asymmetries in the kite are being amplified because the frame and sail are distorting, and it simply can’t fly straight anymore. I was flying with the winder clipped off to a waist belt, so I hadn’t noticed how hard it was pulling until I saw it flying off the wind. A quick check of the tension on the line and I knew I couldn’t reel it in by hand.

Most kiters will tell you that the only way to wind kite line is to walk the kite to the ground and then reel the line up off the ground with no tension on it. If your flying locations are all big wide grassy fields, that approach works quite well and puts the least load on the kite, line, and flyer. But not every location offers this convenience, especially when the kite flyer is flying in order to do aerial photograph.

Self Portrait at Wailea Bay

Lucky for me, there’s enough room at Kauhola Point to tie off and walk down. But not so much that I could get all of the line down in one pass. I tied off to one of the many cement posts that dot the point and used one of my spare carabiners to bring the line down.

I wish I had photos to share of this part of the session. I don’t. I was too busy trying to bring my kite and camera down before my DSLR was dunked in the ocean, slammed into the ground, or wrapped around the lighthouse. I was also too busy swearing at myself as the wind steadily increased. What had started off as a nice five knot blow was well over fifteen by the time I had things ready to start walking the kite down. Even with gloves my hands were killing me by the time I brought it down far enough to get my camera off the line. With the camera secured, I thought the kite could be brought down a little more easily. I was wrong.

When I tell people that I do aerial photography using a kite, most people conjure a mental image of a small store-bought Gayla delta with a microscopically small camera taped to the kite or to the kite line. The reality is that I often fly over two pounds of camera gear using a kite that can lift it with ease.

T2i KAP Rig - Front

The kite I was using was never designed to fly in anything more than about ten knots of wind. I had almost doubled that, and the pull on the line was well over forty pounds. It’s hard to appreciate just how much pull a large kite can generate until you’re on the other end of the line.

I almost got it. Almost. Toward the end I found myself wishing the line would just break so it would all be over. I didn’t really want to lose the kite. It’s expensive, and I didn’t really want to have to replace it. But I would’ve offered it up to the sea if it meant I could be done.

Which is almost how it happened. With only fifty feet of line to go, the kite wrapped around the lighthouse and then tried to fly back. The line caught on one of the many bolts that hold the monopole together, and separated. The kite narrowly avoided flying into the ocean by hitting a tree. The line collapsed to the ground, and so did I. With what strength I had left, I cheered.

Getting a kite out of a tree is a matter of having the right tool for the job. I typically travel with some sort of pole in my kite bag. I was lucky enough to have a 24′ painter’s pole strapped to the top of my car, so I used that to fish the kite out of the tree. The wind continued to rise, and the kite was still giving me a good fight until I pulled its spine out and wrapped it up.

I still had a fair bit of work to do before I could pack up. My line was a shambles, my gear was spread all over the place, and I’d managed to lose my sunglasses. I put up a PFK Nighthawk to clear the line and wind it on cleanly. By the time I had all the line up in the air and the tangles free of the winder, the Nighthawk was pulling hard enough to lift my rig. It was well over twenty knots. I did hang the rig from the line and tried to make a few more pictures, but they were flops. Eventually I packed everything away and headed home.

It wasn’t until I was driving back toward the highway that I realized how lucky I was. Sure, the session was less than satisfying. I could classify it as bad. But aside from losing about a hundred feet of line, I had no real loss of gear. I recovered the kite, the rig was taken down safely, and the camera suffered no damage. Not a bad way to end the day. I even found my sunglasses!

– Tom

Posted in Hawaii, Kite, Kite Aerial Photography, Photography | 2 Comments »

Life’s a Beach

Posted by Tom Benedict on 22/02/2012

I didn’t get to pull out my 4×5 camera this past weekend. By Friday afternoon it was pretty clear I’d caught a cold. So I spent most of the weekend indoors wishing I could be outdoors. By Sunday afternoon, however, I was ready to risk anything to get out of the house. So we went to the beach. I came prepared!

Most of the time when I go to the beach I’ll either pack my KAP gear or I’ll pack a book and a beach chair. This time I brought my KAP gear, all my kites, a two-line kite (a Jon Trennepohl Widow), the full-spectrum Canon XT I have on loan, my shortwave radio, a long-wire antenna, and my book. But no beach chair. I figured if I needed to sit down, I could just flop on the sand.

The wind was perfect. So while everyone else was taking off their sandals to get in the water or setting up their chairs to read by the seaside, I was muttering under my breath about not wasting good wind and trying to get everything set up in the shortest amount of time possible. Up went the 6′ rokkaku, out came the rig and transmitter! I got my T2i airborne with the video down-link, and got down to business.

Blue Umbrellas

The wind was a little stiffer than I liked, but other than that conditions were perfect. The sky was a little hazy, but not so much that I didn’t get good shadows. The video link worked like a charm. I was able to compose a number of photographs that I knew I’d like when I got home. I exposed 39 frames — a far cry from the hundreds I typically do when not using a viewfinder. Of those only a couple were real tossers. It was a matter of choosing the best rather than choosing not-the-worst.

Sand Play

I brought my T2i down and switched to the full-spectrum Canon XT. I stuck my Hoya R72 filter on the end of the lens and did some IR KAP.

Hapuna Prince Resort in the IR with Kohala

I was really pleased to see how well the IR cut through the haze in the air. This is typical of IR photography, but it’s neat to see it when it happens. In the distant background you can see individual clumps of trees on Kohala Mountain showing up brightly in the near-IR.

The Canon XT doesn’t have live view, so I can’t use the video down-link with it. I was a little surprised to see one of my carefully composed T2i photos and one of the blind-aimed XT photos were almost identical in terms of composition! So I put them together as a visible/IR diptych:

Visible and IR

The card in the XT is fairly small (512MB?) and I had it set to make RAW files, so I knew I couldn’t take too many pictures before the card filled up. Eventually it was time to land the camera and pack the KAP gear away. Then out came the shortwave radio!

Two weeks ago I brought my kites to the local radio club meeting as a sort of show-and-tell. Mostly it was to get the gears turning to see what the club members came up with. A number of people were interested in doing some QRP DX using a longwire vertical. Someone else had the idea of sending up a pair of handhelds, set up as a cross-band repeater. The ideas bounced around faster than I could keep track of them! By the time we left, everyone was making “Hmmm!” noises. It was a fun meeting.

For my part, I wanted to see how a long wire antenna would work out. I don’t have my General license yet, so I can’t transmit on the HF bands. But I can listen! I’ve had battery powered shortwave for the last ten years or so that goes out to 120m. When I bought it I also picked up a 10m antenna. Not ideal for the longer wavelengths, but decent for the shorter ones and better than nothing. Just for grins I tied the antenna to my kite line and ran it up. I couldn’t develop enough height to be too worried about static buildup, so I just plugged it straight in.

And boy did it work! I picked up transmissions from Japan, China, and Australia. I got some others I couldn’t identify, but already that sounded pretty cool. I tried some of the longer bands, but the short antenna just couldn’t pull them in. Besides, I didn’t have a decent ground plane, so I knew I wasn’t getting everything out of it that I could. I packed everything away and started making plans for setting up a quarter wave ground plane antenna that would get me out to 120m. Only this time I’ll add a static discharge resistor!

As I was packing my radio away and landing the rokkaku, I realized the wind was picking up as the sun got lower rather than the other way around. The normal pattern is to have the wind drop off at sunset. Aaaah, but we weren’t having normal weather! (If it’s any indicator, Mauna Kea and Mauna Loa had a snowstorm Saturday night.) So I pulled out the two-line kite.

I fly our Widow, but really it’s my wife’s kite. I’m more of a single-line guy. She saw me throw it in my kite bag when we were packing for the beach, but didn’t say anything. As we were driving down I asked if she’d be interested in flying it. She looked a little pained, but shook her head. Ever since her brain surgery, she’s had a hard time adjusting to the loss of her stereo vision. She explained that she was worried she wouldn’t be able to fly it with one eye. I thought otherwise, but I held my tongue.

Once the Widow was airborne, though, I had to see her try. It was good clean wind, the sand was clear for most of the window, and I could see her watching out of the corner of her eye. So I waved to her and gestured for her to come over. She stepped in, took the handles, and flew it just as she always had.

Back In Command

Eventually she had a hard landing in the sand that busted a spar. I didn’t care. A busted spar can’t hold a candle to the look on her face. It was great to see her at the controls again.

As the evening drew to a close I put up the PFK Nighthawk that Pierre Lesage and Heidy Baumgartner gave me when they visited Hawaii about a  year ago. The wind was really too light for it to do any lifting, but you just can’t beat the wind range on that kite. Pierre has used one to fly a camera in 45 knot wind. I was flying mine in less than five knots. On a whim I decided to re-create a photograph I’d made during Worldwide KAP Week 2009.

PFK Fine Guidance System

I’ll get out with my 4×5 next weekend. For now life’s pretty good.

– Tom

Posted in Kite, Kite Aerial Photography, Photography, Radio | Leave a Comment »

Playing with a View Camera

Posted by Tom Benedict on 18/02/2012

Back in the mid 90’s, my wife bought me a Bender Photographic 4×5 monorail camera kit. These kits came as a set of precision routed pieces of wood with some really good instructions on how to assemble them into a working view camera. Shortly after she got me the kit I came down with bronchitis. Not the best conditions under which to work with wood, but by the time I was well I had a new camera.

Bender 4x5

When it was done I outfitted it with a Fujinon 150mm lens, loaded up some film holders, and began my foray into large format photography.

I believe that every photographer should try their hand at large format photography at least once. To be honest I think every photographer should keep a view camera around and use it from time to time. Not because of the movements, which are a real joy to use, or the large negative, which is a joy to look at. It’s the ground glass.

The image on a view camera’s ground glass is upside down and backward. To many people this sounds like an awful burden to have to work around. I believe that it is the view camera’s greatest strength. It forces the photographer to see in terms of color, shape, and arrangement rather than as discrete objects placed within a scene. The view becomes an abstraction: a collection of geometric shapes that can be arranged by moving the camera. Sky ceases to be sky and becomes a wedge of blue. Trees cease to be trees and become green or brown blobs. People cease to be people, and hint at motion or action. The everyday melts away and the view takes on the appearance of an impressionist painting.

Bender 4x5 in Waipio Valley

And that, really, is the point. Photography is no different from painting when it comes to composition. Yet few photographers are willing to step outside the boundaries of their lenses and their cameras to embrace another art form. The view camera encourages this.

I’ve been in a photographic funk for several months now. I stopped doing kite aerial photography and even found that ground photography didn’t come easily any more. My daughter helped get me back into ground photography, and only last week I finally got my camera back in the air. But maybe I need something different from each of these. I think it’s high time I pulled out my view camera again and spent a little time remembering how to see.

– Tom

Posted in Photography | 2 Comments »

Always Check Your Gear

Posted by Tom Benedict on 15/02/2012

I had two reminders recently that you should always check your gear:


The first ties back to when I was trying to get my monitor calibrated. I had my colorimeter, but couldn’t find the license key to my software. I finally got that resolved (yay!) but the first color calibration looked… odd… So I did what any self-respecting meddler would do: I started pulling things apart.

I’m still using the Spyder 2 Express I got when I did the Worldwide KAP Week 2009 book. It doesn’t have a number of features I’d really like, such as gamma correction. But it does a good job with color. It’s old enough that the base design works with CRTs. To make it work with an LCD you snap a little filter unit on the bottom of the colorimeter head before placing it on the monitor. The filter unit has a honeycomb mesh to constrain the input angle of the light, and it also has a light blue filter to bring the output of the LCD into the sensitivity range of the colorimeter. I only ever use this on LCD monitors, so I’ve never had cause to remove the filter unit. Out of curiosity, I removed it.

I was appalled to see mold growing in there! It was on the filter as well as the colorimeter. Living in the tropics makes this a pretty common theme, but it’s never fun to see stuff growing on camera or computer gear. A quick wipe with a damp towel cleaned the colorimeter. I managed to pop the blue filter out of the filter unit and cleaned it as well. Once everything was put back together, my monitor calibrated nicely. Whew!


The other reminder ties back to that full-spectrum converted camera I got to use for the KAP flight over CFHT headquarters. The camera is a Canon Rebel XT: an older model. When I compared the JPG files I got off of it against the ones from my T2i, all I could think was, “Thank goodness modern detectors are larger! These files are tiny!”

Yesterday I did some test shots at our summit facility to try out the field of view of several lenses. The idea is to mount one of these cameras at the telescope next door, pointed back at our dome. We can then use that camera to do dome assessments after a storm passes through, to make sure our dome isn’t covered by snow and ice. (A couple hundred pound sheet of ice falling on a telescope is a veryvery bad idea.) So we wanted to make sure that we got the resolution we needed to be able to do a fair assessment. I made the pictures using a 35mm, 50mm, and 100mm lens, and emailed the pictures to our head of IT, who is heading up the project.

He wrote back and asked why I had the camera set to half resolution. ??!  !!!!!! Since borrowing the camera, I had never even checked! Sure enough it was set to make the smallest possible JPG files. I changed it over to making large JPG+RAW files and repeated the earlier photographs. The resolution still wasn’t close to my T2i, but it was far far better than it had been before. Better still, the RAW files gave me some much better options for post-processing than the JPG files did.

So now I have this burning need to get this camera airborne again. But this time making full-resolution RAW files. I just wish I’d checked before that flight over CFHT. I really liked the angle I got on one of them, and have no guarantees of repeating it on a subsequent flight.


Every photograph represents a unique moment in time — a unique opportunity to see the world around you and share what you see with others. In the case of the full-spectrum camera, I may not be able to re-create the particular view I had, but chances are I will. In other cases those opportunities only happen once. I can never re-photograph the Kauhola Point lighthouse because it was torn down several years ago. I can never re-photograph my children as infants because now they are grown. I can never re-photograph Wall Arch in Arches National Park, because it collapsed some years back. Photographers have to make the most of every opportunity they have. Do-overs are rare.

Always always check your gear.

– Tom

Posted in Photography | Leave a Comment »

A Second and A First

Posted by Tom Benedict on 11/02/2012

I got out again at lunch today and flew my video assisted KAP rig for the second time. But before I did that I flew my first IR-converted camera.

The camera is a full-spectrum modified Canon Rebel XT. The conversion was done by a guy at work who did the conversion for the CFHT Cloudcams. (The camera I used is actually a backup cloudcam.) The conversion involved removing the camera’s IR blocking filter from the front of its detector, and replacing it with a piece of BK7 glass. This lets infrared light reach the camera’s detector, but still maintains the same optical depth so that the autofocus hardware in the camera still works.

The flight itself went great. It flew exactly like an unconverted camera, except I couldn’t use my video down-link with it. The camera predates live view on the Canon DSLRs. So it was back to aiming by eye. I came away with some keepers, so I’m pleased.

CFHT Headquarters in the Near IR

The flight took place near the headquarters of the Canada-France-Hawaii Telescope Corporation where I work, which is the subject of the photo. No, it’s not snowing here. That’s grass on the ground.

The camera focuses like a champ, but the exposures aren’t quite on. My guess is the exposure sensors have a different response to infrared light than the focal plane detector. For this flight I metered manually, but I think a better approach in the future would be to figure out what the exposure offset is and just dial it in with exposure compensation.

Once the IR camera was safely landed and put away, I stuck my T2i on the rig and plugged in all the video hardware. The wind was stronger than during my first flight, so no surprise landings. But it was also more turbulent. So getting the compositions I was after was harder. Still, it worked out well. Here’s the visible light version of the above photograph from a slightly different vantage point:

CFHT Headquarters

I wanted to get the whole building in the frame without the foreground building intruding, but the wind wasn’t cooperating. Still, this was a nice tight composition. Except for normal RAW processing, this is straight off the camera. No cropping, no rotating, no nothing. I am super super pleased with how well this video downlink setup is working out.

Several years ago when I first flew over CFHT HQ, I did some directly-down photos of the indoor garden and the lanai area. They were completely blind-aimed. For some of them I couldn’t see the building at all, and was going entirely by feel. I got lucky and got some good images. So I tried to do the same with this setup, where I could compose them at will.

The first, the indoor garden, worked out quite well:

Complex Rooflines

Except for a little horizontal perspective control tilt to get my horizontals horizontal, I didn’t do much of anything to this photo. It really was rotated that straight from the get-go. Ok, ok, to be fair the wind was really cooperating for this one. I had plenty of time to half-press and focus, do the final composition, and trip the shutter. Not so for the lanai:

CFHT Lanai

I really wanted this one to be as well-aligned as the previous photo, but the wind was not as cooperative. By the time I’d walked in to position to make this one, the kite was bucking around and the rig was swinging. I could get the focus and composition, but not rotation. Two out of three. If I rotated, the tilting of the rig meant I wouldn’t always get the full courtyard in the shot. I did the best I could and walked away with some good photos. As with the full building photo, this one is almost straight off the camera. Just normal RAW processing. No cropping, no rotation.

Right after tripping the shutter on this one, the wind dropped. Kite and camera started coming down a little too fast for comfort. When I set up I knew that might happen, so I used too much kite for the wind. After the wind dropped I was glad I’d made that call. It was a bit of a mad dash to bring in line and land the camera safely, but everything made it down without a scratch. Camera went back in the camera bag, KAP rig and radio went back in the KAP bag, and the kite went back in the kite bag. With ten minutes left in my lunch hour, time to go back to work.

All in all I’m liking this video down-link more and more. It’s a good direction for my KAP to go. But as I hinted at in my last post, there are some changes I’d like to make to my gear. I spent the last of my earnings from my last Getty sale picking up the hardware I need to get all this done, so it’s not a question of if. It’s a question of when:

  • I’m adding a new switch to my radio. Flipping the switch will power on all the ground-side video gear (receiver and monitor), and simultaneously trip one of the servo channels on the KAP rig. On the KAP rig I’m installing a relay switch that will power on the video transmitter power when the switch on the ground radio is flipped. So flipping this single switch off will power off all the video gear on the ground and in the air. And flipping it on will power everything up.
  • I also picked up a boost power supply. It pegs at 9.5V, but I might swap it out for a 12V unit at some point. The idea is I can feed it 6V (or anything else between 1.5V and 9.5V) and it’ll output a nicely regulated 9.5Vdc. Add a line filter to get rid of the harmonics from the switching power supply on the boost board, and I can power my video gear off of the rig’s battery.
  • Finally, I ordered some reverse polarity SMA plugs with coax tails on them. I’m planning to make a 5.8GHz cloverleaf antenna for my video transmitter and a 5.8GHz skew planar wheel antenna for the video receiver. These are circularly polarized antennas, so they should reject a lot of the linearly polarized interference from other 5.8GHz devices. They also offer some modest gain, which should make for a stronger signal overall.

Yup, I’ve caught the bug. Now I just need a weekend with good weather and clean wind to fly in. Here’s hoping it’s the one that starts tomorrow!

– Tom

Posted in Electronics, Kite Aerial Photography, Photography, Radio | 1 Comment »

Back In The Air

Posted by Tom Benedict on 07/02/2012

I’m back in the air!

A couple of weeks ago I got my statement from Getty Images. I’d sold another kite aerial photograph of Hawaii. I told my wife, and from there we got into a discussion of photography in general and the mental roadblock I’ve been trying to work through. It was a really good conversation. She did more than her fair share of verbally kicking me in the butt to get me off top-dead-center. Her closing argument was that KAP gave me a unique perspective on a unique place, and that obviously someone was willing to pay money for it. Her final statement: Get your KAP gear back together and get back in the air.

So I did. I really did get all my gear back into my KAP bag. But for the past two weeks the weather has been anything but cooperative. When there was wind, I couldn’t fly. And when I could fly, there was no wind. Or there was rain. Or gusts. Or something! It was driving me nuts. I tried again last Saturday. One location was like a sand blaster, and less than half a mile away it was dead calm. I griped. I groaned. But no way was I putting my camera up in that. Sunday I wrote a post about trying to get back into KAP, and how uncooperative the weather has been. But I didn’t post it. Somehow it just seemed too whiny and unproductive.

Yesterday I brought all my stuff in to work on the off-chance I’d have wind during lunch. It wasn’t great, but it was more than I’d had in over a month. I gave it a try.

Winds were blowing kona (the opposite of the normal trade-winds), and I’d made some changes in my gear, so I went to a favorite gear testing spot. It’s not the most photogenic place on the island. Not by a long-shot. But it’s open, it’s grassy, and when the wind blows from the right quarter the nearest power lines are a good distance away.

The big change in my gear is that I’m flying with a video down-link.

5.8GHz KAP Gear

This is a first for me, and a big departure from how I’ve done KAP in the past. I’ve always been a predominantly RC-KAP kind of guy, but I’ve always done blind aiming, where I look at the camera and guesstimate what it’s pointing at. I’ve become reasonably good at it, but it’s not an exact science. I’ve missed my fair share of good photos this way, simply because the compositions I got didn’t give me enough to work from. This lunchtime test session was the first time I’ve had a viewfinder to work with.

Before getting into how I liked doing video-assisted KAP, this is the entire 25-shot contact sheet from the flight:

VKAP Session 1

Already this bears almost no resemblance to any previous KAP flight. For starters, there are far fewer photos. Next, a higher percentage of them are workable. Next, only one is unacceptably blurry. All in all, the flight went well! Here are some specific photos I worked up:

Second VKAP Photo

This was the second photo of the session. Except for RAW processing, it’s exactly how it came off the camera. Normally I aim blind from the ground and make several photos as the camera wozzles around in the air. This gives me a pepper-shot style selection to choose from. After the flight when I’m processing the photos, I’ll pick the one with the closest composition to what I had in mind and work the photo from there. In this case the composition was right from the get-go. No rotation or cropping was done on this after the fact. The building behind me provided the rooftop I photographed as an abstract during WWKW 2011.

Kahilui Theater

A nearby landmark is the Kahilu Theater. I’ve photographed this on several occasions from my earliest days of KAP. I’ve probably exposed over a thousand frames of this building, but only a handful turned out to be useful. Often the cropping necessary to get a decent composition trimmed away too much of the frame for it to be usable. In this case the base composition was right off the camera. Unlike the previous photo I did some more work on this one. In addition to RAW processing I rotated the photograph to flatten the horizon, and applied vertical perspective control tilt to get my verticals vertical. The horizontals were left as-is since no effort was made to line up on the front of the building. Yes, you can do architectural photography from a kite.

That Damn Tree

That damn tree!

This tree has been another repeat subject during testing. I still haven’t photographed it in a way that I’m happy with, but this came awfully close. Except for RAW processing, this is straight off the camera. No cropping, no rotation, no nothing.

Fly This!

This was the last frame from the session, just to verify everything was working. (But I kind of like the whole Billy Idol fist-at-the-camera thing! Even if I’m not wearing gloves and have a winder dangling from my pinkie. I’m still channeling Billy here!)

So how did this all work? Surprisingly well!

I did have one scary moment when I was composing a photograph of the town and grass suddenly grew up from the bottom of the frame! I looked up and saw my camera had landed on the ground. Clearly this is better done as a tandem team the way Fanny and Anthony work, or in more solid wind where the camera will stay in the air where it belongs. But hey, that’s why I do my testing where the grass is soft and the rocks are scarce.

My method, in practice, was:

  • Set the camera to shutter priority, 1/2000 sec. (This was not always achievable because of lighting conditions, unfortunately.) Single shot, daylight white balance, ISO 100.
  • Install the camera in the KAP rig – plug in the Gent-FOCUS shutter release cable and the video down-link cable.
  • Power up the camera, rig, and video transmitter and turn on Live View on the camera.
  • Launch the rig.

One step I didn’t do during this flight was to set my focus/exposure point to the center of the frame. It was way off to one side because of some ground photography I’d done earlier in the morning. I didn’t even think to check until the camera was a hundred feet away! But I was still able to do decent KAP.

Once the camera was in the air and in a good location to photograph the subject, my practice was:

  • When the camera is in position, rough-compose the image.
  • Flip the shutter switch forward (equates to a half-press on the camera’s shutter button).
  • Wait for focus lock (focus rectangle goes green).
  • Final-compose the image and wait for the camera motion to settle.
  • Flip the shutter switch backward (equates to a full-press / release on the camera’s shutter button).
  • Repeat…

I’m still not smooth with the new gear, but I think I’m to the point where I can use it somewhere that’s a little more photogenic. One future change I’d like to make is to add a remote relay that’s tied to an unused channel on my radio to power the video transmitter on and off remotely. Along with this, I’d like a second switch to power the video receiver and monitor on my ground radio as well. I find I spend a lot of time positioning the camera in the air by eye before I ever look at the video monitor. If I could turn off all the video gear and only turn it on to compose the photograph, it would save on batteries and make for longer flights.

– Tom

P.S. There’s a second change I’d like to make: The video reception is noisy. I’d like to swap out the stock antennas for a pair of cloverleaf circular-polarized antennas. Project for another day.

Posted in Kite Aerial Photography, Photography | 3 Comments »

The Joy of Calibration!

Posted by Tom Benedict on 06/02/2012

Some months back I built out a new computer. Some people enjoy getting a new computer, but I hate it. I’m a creature of comfort, and once I move into a computer I like to stay there as long as possible. I also know that despite being a digital pack-rat, I tend to lose things that are actually important — like my software license keys.

I did better this time. I actually had licenses for almost everything I use, including my CAD and CAM packages. The only two I couldn’t find were Photomatix, which is no huge deal since I don’t do much HDR, and the license to my monitor calibration software. The folks at HDRSoft were great about getting me my license key for Photomatix, which I now keep with all my other licenses. But the monitor calibration software was a black hole.

If you’ve never used a calibrated monitor, you won’t appreciate what a real pain in the rear it is to use one that’s completely uncalibrated. When editing photography, it’s hard to know what something will look like when printed. Colors are off, tonality is off, it’s a mess! Almost three months later, I was still running uncalibrated. I knew my new photos had a strange color cast, but I had no way to figure out what it was.

Over the weekend I tried an experiment: I took the configuration file off of my old computer and stuck it in the right directory on my new one. Lo and behold, the software ran! I don’t know where the license key is in that file. Quite frankly I don’t care. It works! I’m calibrated again! And the config file now lives with the rest of my licenses.

Now I’m dealing with the aftermath of editing photographs on an uncalibrated monitor. Gaaaah! So many of my photos were messed up! Ah well. I have my work cut out for me. Meanwhile, I’m back in my comfy spot. Calibrated and good to go.

– Tom

Posted in Computer, Photography | 1 Comment »

CAD Under the Influence

Posted by Tom Benedict on 03/02/2012

Don’t do CAD work under the influence. Bad bad bad idea. Almost as bad as operating heavy equipment under the influence, except that the risk of life and limb is a lot less with CAD. But the combination can still be nasty.

I’ve had intermittent lower back problems since I was about nineteen. I remember my first real attack. I was camping with my parents and pinched a nerve that immobilized me below the waist. I holed up in the tent and didn’t move for 24 hours. What else was I supposed to do? I saw a doctor when I got back, but for some reason I’ve had very little understanding from the medical community when I describe my back problems. The first doctor’s advice: “You’re young. You’ll get over it.” Mmmm… no. I never did get over it. And they never did anything beyond palpating my lower back. No x-rays, no MRIs, no range of motion tests, none of it. I was a little disappointed. And of course I re-injured it not long after.

That became a pattern: Hurt my back, see a doctor, get blown off by the doctor, hurt my back. I finally convinced a doctor to let me get some physical therapy. The PT took it seriously. They did range of motion tests weekly, checked my progress, gave me exercises to strengthen my core, etc. All of which helped. It was years before I had another attack. But it still came back. Having intermittent back problems is like having a cousin who keeps dabbling in petty crime, but has no idea how not to get caught. “Dude, I’m in deep this time. Deep! I need help. I know you’re there for me, right?” Riiiight. Just as soon as you think you’re free, the cousin shows up again with another sob story.

Yesterday I was doing CAD work on a camera design we’re finalizing. Late in the game I realized we would need to be able to pick the camera up in order to install it, and there was no place we could safely grab it! The biggest grabbable surface is the cryo cooler, which is on a fairly delicate anti-vibration mount. It can support the weight of the cryo cooler, but not the weight of the rest of the camera. I had to design in handles!

I looked at rack mount handles, drawer pulls, and a bunch of other stuff. But then I realized I could change some of the parts slightly and essentially get handles for free. Yay! So I rooted around in the tool bag I keep under my desk to find some test “handles” (aka a screw driver, a flashlight, and a telescoping magnetic rod) to see what diameter I’d need in order to be comfortable. When I straightened up again, my back went out.

It’s not like any of these things were heavy. I’d just moved wrong and put myself in a position where I had no leverage to support my spine. It happens a lot with lower back injuries. It’s not picking up the two ton weight that typically gets you. It’s picking up the pencil you dropped on the floor.

I quickly did some relaxation exercises and took an anti-inflammatory pain killer. It hit quickly, and did a good job of relaxing my back so I wouldn’t pinch other nerves and do further damage. But it meant that for the rest of the day I was doing CAD under the influence.

ANYONE who thinks that over the counter pain killers don’t count as drugs is fooling themselves. Coffee is a strong stimulant. Ibuprofen and acetaminophen can make you seriously loopy. By mid-afternoon I’d taken a second pain killer, and my CAD model was starting to show the effects. By the time five o’clock rolled around, I was more than ready to stop before I did any more harm.

When I got in this morning I was appalled. I’ve been really pleased with the design of the camera thus far. It’s functional, it’ll be straightforward to make, and for the most part it’s still pretty. But OHMIGOD! What the @#$% happened yesterday?! I couldn’t believe some of the changes I’d made while I was on those pain killers. It was hideous! It was worse than having an over-sugared four year old with crayons making design changes. I have no idea what I was thinking yesterday, but I knew it couldn’t stay like that.

Thank goodness for backups. And for heating pads.

– Tom

Posted in Engineering | 1 Comment »