The View Up Here

Random scribblings about kites, photography, machining, and anything else

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Posts Tagged ‘WWWK’

Catching Up

Posted by Tom Benedict on 15/10/2010

I missed most of Worldwide KAP Week 2010.  A few weeks previous I’d come down sick with a cold, and just never quite shook off the cough.  It didn’t help that my job took me to the cold dry air at 14,000′ elevation over and over (and over!) during and after the cold.  In the end I came down with walking pneumonia.  This left me with no energy and a wracking cough through most of WWKW 2010.  I did get out, I did send pictures in to the book, but it wasn’t the happy time I’d planned.  C’est la vie.  Until next year.

In the end I was sick for well over two months.  I finally got my clean bill of health today, and should return to duty at the summit tomorrow morning.  Meanwhile I’ve been working on a cryostat at headquarters, and finally started flying kites again about a week ago.  Unfortunately all this came together in a not so comfy way today.  It all ended well, but getting to the end of the day was a trial.

At lunch I broke a spar on my Premier Kites Widow.  Plain and simple.  Dumb crash, dumber re-launch, and now I have to cut a new P-200 spar once I get home.  Thank goodness for spares!

The real fun has been this cryovessel.  I was testing the idea that you could boost the performance of a closed-cycle cooler by using thermoelectric coolers, or Peltier junctions, between the closed-cycle cold head and the cold surface.  It worked, after a fashion, and I think it bears re-examining with a properly sized cascaded Peltier junction.  But for our application I just couldn’t get enough cooling power out of the thing to get the delta-temperature I was after.

During this testing I wound up putting something like 30W of power through a two-stage cascaded cooler, but the cold head simply couldn’t remove the heat fast enough.  Within a few minutes I had a cold head at -150C, a cold surface at -100C, and a Peltier junction at a soaring 38C.  I killed power, brought everything back down, and let things hit steady-state before killing the power to the cooler.

What that told me, though, was that the biggest delta-temperature in the system was across the link between the cold head and the cold surface.  I also realized if I minimized the dT, I could switch the gas in my cooler and possibly hit my target temperature that way.  Time to make new parts!

So I replaced that link with a new one.  The old one consisted of ten strips of 6.5″ x 1.0″ x 0.010″ copper in a nice neat stack, or 6.5″ of 0.100″ sq in copper.  I replaced it with 2.8″ of 1.5″ diameter copper.  At 60W of load the first one got me about 52C dT.  With this new one I should be able to keep that under 2C of dT.  If the cold head reaches its ultimate temperature of -158C, this should give me a cold surface temp of -156C.  If that happens, I can change gases and potentially hit the 77K, or -196C temperature I’m after.  Time will tell.

For the record, I hate machining copper.  Oxygen free high conductivity copper is even worse.  It’s like machining stale bubblegum.  Tools dig instead of cutting, the copper oozes out of the way instead of making nice chips, and it takes all manner of tricks to pull off clean cuts.  I got the parts made, but the final steps of tapping the M3 holes in the thing gave me the willies.  After a thorough cleaning, I opened up the cryostat, installed the new parts, and closed it back up.  It’s on the pump now, and I should have a chance to start cooling it over the weekend so I can work with it on Monday.

But what I’m really looking forward to right now is a new spar for the Widow, a weekend of good weather, and a chance to get out and make up for what I missed during Worldwide KAP Week 2010.

– Tom

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Worldwide KAP Week 2010 Begins!

Posted by Tom Benedict on 10/09/2010

If you’re active in the world of kite aerial photography, chances are you already know Worldwide KAP Week 2010 starts tomorrow.  It runs from Saturday, September 11th, through Sunday, September 19th.  (Yes, that’s also “Talk Like a Pirate Day”.)  If you already have KAP gear, get out.  Wherever you are, get out over the next nine days and fly a camera.  Take pictures.  Have a good time.

As for me, I’m taking the entire week off from work.  Some people think that’s silly, but it’s one of my only opportunities during the year to really get out and dedicate a big chunk of time to doing KAP.  Looking back at the pictures I made during Worldwide KAP Week last year, and everything that’s happened since, I have a pretty positive feeling about WWKW 2010.  These are the big changes in my gear and technique:

  • I picked up a Dopero early this year, so I can fly a heavier rig in lighter wind.  From 3.5kt to 25kt, I’ve got my kites covered.
  • I’ve worked a lot on my panorama technique, added a Ho/Ver axis to my rig, and hope to make a number of good, printable panoramas.
  • I’ve also worked on my sunrise/sunset/golden-hour photography, and hope to work in better light during WWKW 2010 than I did during WWKW 2009.
  • Finally, I’ve been experimenting with graduated ND filters in the air.  I think this is the last tool I use for landscape photography on the ground that hasn’t been available in the air.  Now it’s all there.

I’ve got spots picked out all over the island, and a list of subjects longer than I can handle.  So no matter what, I doubt I’ll come away from WWKW 2010 disappointed.  It should be good.  I checked the weather and wind for tomorrow morning (my first sunrise outing ever!) and it looks like there should be nice wind on Mana Road.  Some years back I did an early morning session on Mana Road, and came away with some nice pictures.  But the foreground was too dark, and the clouds over Mauna Kea were blown out.  This time I have tools for dealing with challenging lighting, so I hope the pictures will be better.

I can’t wait!

– Tom

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KAP in the Golden Hour

Posted by Tom Benedict on 30/08/2010

One of the things to look for in a photo club is honesty.  There are clubs where it’s all about the kudos and patting each other on the back.  In my mind these really don’t do a a photographer much good.  But then there are the ones where you get honest critique, whether it hurts or not.  If you’re really looking to improve, it shouldn’t hurt at all.  Honest critique, after all, is one of the best helping hands an artist can have extended to them.

At a recent photo club meeting, one of the members I respect highly, both for his artistry and for his honesty, gave me a critique on a set of images I showed.  It boiled down to this:  Great vantage point, rotten light.  Ouch?  Not really.  He’s right.

Until recently most of my KAP work has been done under the bright midday sun.  In the back of my mind I knew this.  Heck, all the work I put into finding the best way to make a panorama revolved around the notion of working in sunny-16 conditions.  And despite having most of John Shaw’s and Galen Rowell’s books on my shelves, I just didn’t manage to put two and two together and see that this was the wrong time to do photography of any sort, KAP or no KAP.  So the critique I got was a much-needed kick in the seat of the pants.  Want to improve my kite aerial photography?  Work in better light.

That “better light” happens during the half hour before and after sunrise or sunset.  It’s known as the “golden hour”, not just because of the color of the light but because of the quality that light brings to a photograph.  They simply look better.

Of course the “hour” part of the golden “hour” is subjective, and depends a great deal on location.  In far northern or southern latitudes, that “hour” can stretch on for hours and hours as the sun slowly sinks toward the horizon.  Here close to the equator it’s about fifteen minutes on either side of sunrise or sunset.  But the “golden half-hour” just doesn’t have that magical ring to it.  So “golden hour” it is.

On the ground, doing photography in the golden hour is only slightly different from doing it at any other time of the day.  Exposures are a little longer, or a lot longer, depending on how late you’re out.  But a tripod fixes that.  If the wind is blowing and you need a faster shutter speed, you can open up your aperture or bump up your ISO.  In the days of film, you loaded a faster film and had done with it.

In the air things are a little more difficult.  The kite is your tripod, and even the most stable kite will still move around.  I fought camera motion during the day by using a 1/1000 or faster exposure speed.  With my camera, that’s simply not available in the golden hour.  With a DSLR, it’s possible to bump the ISO to 200 or 400 without suffering much of a penalty with noise.  With my compact camera, ISO 100 is as fast as I can go and still get acceptable noise.  And unfortunately, during sunrise and sunset is when the wind is at its squirreliest.  On the West Side of Hawaii, the wind is largely thermal in origin.  Thermals collapse as the sun sets, so everything is in flux during the golden hour.

One other significant difference is that on the ground the photographer can make rational choices about metering in order to render a subject the way they intend.  In the air you have to set and forget.  In broad daylight, I came to the conclusion that using the sunny-16 rule was the right way to go: manual exposure mode, fixed aperture, and a fixed shutter speed based on a 1/ISO f/16 starting point.  Toward sunset the light is changing constantly, so a manual meter setting simply isn’t the right approach.  I had to come up with something else.

All of this makes life hard.  Hard, but not impossible.  I started off re-learning how to photograph during the golden hour from the ground.  I skipped the tripod, not wanting to lure myself into a false sense of security.  Several evenings of exposure tests toward sunset at Hapuna State Park got me going in the right direction.

The first thing I found was that metering toward the sun gave shutter speeds close to what I was using for sunny-16 conditions.  This meant doing foreground silhouette panoramas with a setting sun in the background could be done almost the same way I make broad-daylight panoramas.  Great no-brainer:

KAP Sunset

Next, I found that when photographing 180 degrees from the sun, I got the best results from metering 50/50 sky and horizon, and then re-composing the photograph:

180 Degrees from Sunset

The shutter times were longer, unfortunately, so my tried and true way of doing panoramas was out.  During the day, I’ll typically make a panorama by tripping the shutter and rotating the rig slowly around the pan axis as the camera continues to take pictures.  At 1/1250 second per exposure, this works fine.  At 1/100 second, this results in a bunch of blurred pictures.  So I used a different approach:  Set the camera to horizontal, meter, and compose each camera location individually while holding down the shutter.  The images that are made as the camera is moving will be blurred, but the ones where the camera is settled in a given orientation will mostly be sharp.

One problem I ran into was the balance between sky and foreground as the sun set.  As the light is falling, the sky actually stays quite bright.  It’s the ground that loses light first.  So the difference between illumination in the sky and on the ground eventually becomes so great the camera can’t capture both.  There are a number of fixes for this, including bracketing and HDR.  But from a strict photographic standpoint the best fix would be a graduated neutral density filter.  I grabbed my graduated ND filter set out of my DSLR bag and headed back out to the beach.

Graduated ND Test 1

The image on the left was done without the graduated ND filter, and the one on the right was with the filter.  The filter I used was an ND 0.6 (two-stop) hard-transition graduated filter from Hitec.  These are large, fragile, and expensive.  But I opted to test it in the air anyway, when I felt I was ready for it.

With all the results from metering, learning to fly in the shifty sunset wind, and the results of the ND filter test, I finally charged all my batteries, packed up all my gear, and put this to the test.

Hapuna + Graduated ND Filter

Compositionally this is quite weak, but it served to demonstrate the metering and filtering I came up with for doing golden hour kite aerial photography.  This panorama consists of nine images made with the camera held vertically.  It’s not without flaws: the rightmost pair of images is too bright, and needs to be brought into line.  But the sky isn’t blown and the shadows aren’t muddied.  All in all it’s a very workable image.

The only catch with all this is that I don’t want to fly my Hitec graduated ND filter again.  As I said, the filter is large, fragile, and expensive.  The filter holder is also quite heavy.  This serves to make my rig heavier, raise the minimum wind speed in which I can fly, and utterly unbalances the rig.  My tilt servo was working overtime to hold the camera in position, which increased battery draw.  No matter what I did, the filter got sand on it, and since it is made of acrylic, there is no easy way to clean the sand back off without scratching the filter.

But the results are compelling enough that I’m motivated to buy a screw-on graduated ND filter strictly for KAP.  I’m pleased with the results I’ve had so far.

The next step is to try all of this with a more photogenic subject with a little more altitude.  Worldwide KAP Week happens in less than two weeks, and is the perfect opportunity to really take all this out for a spin and see how it works out.

– Tom

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A KAP Outing that Wasn’t

Posted by Tom Benedict on 22/11/2009

Since finishing the Worldwide KAP Week 2009 Book, I’ve had more time to do photography, and to at least attempt to do KAP.  Last weekend I got out of the house for a few hours to do some KAP up on Mana Road, a dirt track that runs from Waimea to Mauna Kea’s Summit Road on the south side of the mountain.  The weather in Waimea was rainy, and my plan was to keep driving up Mana Road until I came out above the clouds.  This worked out better than I thought, and I eventually got to do some KAP at a large water shed.

The Water Shed

The photo received some positive comments when I posted it on Flickr, including one from someone who said how much they enjoyed seeing pictures of Hawaii that don’t appear in the tourist literature.  In looking through the photography I’ve done, I realized a good percentage of it has been done at beaches, or in places that are stereotypically tropical Hawaii.  I hate getting stuck in a rut, so the comment on the water shed photo was timely.  Exactly the kind of direction I need!

Yesterday my wife took my daughters to dance, so my son and I threw our stuff in my Jeep and headed out.  My plan was to hike out to some remote kipukas on the slopes of Mauna Loa and try my hand at KAP there.  The wind was favorable, but as it turns out the weather wasn’t.

A kipuka is a forested cinder cone that has been surrounded by fresh lava.  This cuts off the kipuka from the surrounding area, making it a pocket ecology.  Kipukas are common wherever there are cinder cones out on a relatively flat area near an active volcano.  The saddle between Mauna Loa and Mauna Kea has dozens of kipukas that host native Hawaiian flora, and numerous endemic Hawaiian birds.  My son packed binoculars to do some bird watching, and I packed my KAP gear.

By the time we got to the turn off to Mauna Kea Summit Road, it was obvious our plans had to change.  A line of clouds was blowing through the saddle between Mauna Kea and Mauna Loa, and already the area we were planning to hike was covered by clouds.  Rather than turn around and call it a loss, we pulled in at Puu Huluhulu, a large kipuka situated at the turn off to Summit Road.  My son and I have hiked this area frequently, and it’s a favorite of ours.  I had some level of hope that we could reach the top before the clouds rolled through, and that I could get a kite and camera airborne before things socked in.  But the clouds moved faster than we did.  By the time we got to the top everything was an opaque mass of white.  My kites stayed in my bag, but my camera didn’t.  A day that’s bad for kite aerial photography is often a good day for ground photography.  The most obvious subject to work with was the twisted trees that grow on Puu Huluhulu.  It’s trees like this that originally inspired the art of bonsai.

Misty Trees

But there were a number of other subjects that also drew my eye.  Completely overcast skies often make for poor landscapes, but they make for great macro photography.  This plant is about as big as my palm, though the adult plants grow much larger.

Fuzzy Plant

When the clouds and the wet and the cold finally got to be too much, my son and I hiked back to my Jeep.  The misty photography and macro photography felt good, but I was still disappointed that we were packing it in and turning around.  But then I remembered just how close the far end of Mana Road was.  Even better, Mana Road does lead back to Waimea.  It’s not the smoothest ride home, but it was a chance to keep the day from ending before it had really started.  I asked, my son said yes, so we headed out Mana Road.

Stream Bed Panorama

Not too far in we ran across a really picturesque stream bed.  The water wasn’t running, which was a little surprising given the amount of rain the area had received recently, but we were fairly high up so things had probably drained well before we got there.  The clouds that had made KAP at Puu Huluhulu impossible had cleared the air between Mauna Kea and Puu Oo, one of the two active vents on Kilauea.  The two steam plumes from Puu Oo and from the lava flow entering the sea near Kalapana were both clearly visible.  I set up my tripod and lined things up to make a panorama.  When I metered the sky and the ground, however, I found I couldn’t get both the foreground and the steam plumes in the same shot.  The sky was just too bright, and the overcast sky made the foreground too dark.  So I wound up shooting it as an HDR panorama.  It wasn’t quite the look I was after, but it served to balance the two strongest elements in the frame.

Pools

By the time I’d finished the panorama, my son had hiked up slope to a really pretty tree.  Rather than follow, I hiked down the stream bed until I reached the pools I’d spotted while photographing the panorama.  The overcast sky made for nice reflections, so I arranged things for a low angle shot that would pick that up.

Lichen

The same soft light that made for good close-up photography on Puu Huluhulu also made for nice macro photography here.  Some recent experiments at work using CombineZP made me want to try the technique in the field.  The idea is to take pictures at a range of focuses, and use CombineZP to take the sharpest part of each shot and combine them into a single image with infinite apparent depth of field.  I don’t know how enamored I would be of this if I didn’t have CHDK running on my A650.  One of my favorite scripts is a bracketing script that will bracket whatever your last control setting was.  I use it to do HDR photography, but it can also be used for CombineZP.  The A650 can be set to do manual focus, so once MF is selected, the bracketing script can be set up to rack focus through a nice wide range, taking pictures along the way.  I set this to do 37 focus positions, shifting by 3 clicks in focus each time.  (The A650 has well over a hundred focus positions, so techniques like this are quite straightforward.)  When I got home I put the files into CombineZP, and got this in return.

Nene

A few miles down the road my son spotted nene off to one side.  I stopped and got out, with some faint hope of photographing them.  Unfortunately the A650 doesn’t have much in the way of long focal length in its zoom range.  I’ve tried several times to photograph nene with my 20D, but light, weather, or the patience of the birds has always thwarted my attempts.  I was overjoyed to find these geese to be very patient with me.  They let me get quite close without reacting much at all.  I was happy to walk away with a couple of good photographs of them.

Nene

Mana Road is miles and miles of beautiful scenery that changes every time you go around a bend.  I’ve been out on it several times, and each time there is something different to photograph.  I still haven’t figured out quite how I’d like to photograph the koa forest the road winds through, so that’s still one I have to return to once I have a clear idea in mind.  Just past the koa forest, though, the road became quite muddy.  At one point the road dropped away entirely, and I was looking out past my Jeep’s hood into space.

I’m sure there are those who would give a loud “WHOOP!” and hit the gas, but I’m not one of those.  I hit my brakes, turned off the engine, and got out to look.  I saw a muddy slope with about a 25% grade, maybe 40′ high, and covered in skid marks.  I wasn’t keen on the idea of driving it, but of course I had to photograph it!

Whoops!

The wind was too gusty to get a stable kite shot, so I opted for my 20′ carbon fiber pole.  This is a converted breem pole I picked up for $20 and stuck a ball head on for photographic work.  Setting up the shot took about as much time as setting up a tripod, and the CHDK intervalometer script meant I didn’t need to remotely trigger the camera.  All that was required was a little patience waiting for the “click!” sounds coming from the camera, and lining things up between shots.

The Watershed

After photographing my Jeep and the slippery slope, I wound up backing out and going down the lower road.  This avoided the inevitable skid, and got us back on track.  A little further down the road we came across a water shed.  This is smaller than the water shed I’d photographed the previous week, but being closer to the road it offered more opportunities for close photography.  These water sheds are essentially large catchment systems used to collect rainwater for the cattle that graze in the surrounding fields.  The roof of the shed has gutters that are piped into the tanks.  When it rains (which it does quite frequently) the rainwater runs off the roof, through the pipes, and into the tanks.  The water in the tanks is then diverted to troughs for the cattle to use.

The Watershed

I’ve driven past this water shed several times, and have made numerous attempts to photograph it.  But I’ve been disappointed with the results.  I know the picture I’m after, but I just never managed to get it.  This time I got close.

Ideally I’d have liked to be about five to six feet to the right, and aimed the camera more to the left.  Unfortunately there’s a barbed wire fence in the way that makes that angle painful, if not impossible.  I’m still working out how to get the shot I’m after, but this one worked out better than the others I’ve tried.

I did finally get a kite airborne once.  I was on the leeward side of a stand of trees, so the air was minimal and tossy at the ground, and blowing like a freight train higher up.  Kite handling was rough, heavy, and not fun at all.  I clipped on my KAP rig and tried to do some photography of a water tank that’s managed by the water department.  With the wind through the trees and the altitude of the rig, I couldn’t hear the shutter whenever I told it to take a picture.  So it was no surprise when I got home and saw that the only picture I had from the one KAP session of the day was a picture of my feet when I tested the shutter on the ground.

Ah well…

So it was the KAP outing that wasn’t, but I still had a good time.

– Tom

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Why Take Pictures From A Kite?

Posted by Tom Benedict on 28/05/2009

“Why take pictures from a kite?”

It’s a question I hear fairly often when I try to describe kite aerial photography to someone who’s never seen me at work.  Oddly enough I never get this question when I’m out in the field.  The reason for this, I’m pretty sure, is that once you see it being done the answer is fairly obvious.

Lighthouse from Up High

In short, because I can.  And because it works so very very well.

The related questions, “Why not do it from an airplane?” or “… a helicopter?” or “… a UFO?” also have a pretty short answer:  Because I can’t.  Or at least I choose not to.  For starters, I don’t have access to a UFO (though as it turns out I do.)  By the same token, I don’t have access to an airplane or a helicopter, either.  Sure, I could rent one, but I’m not a pilot.  I could rent a pilot, too, but they cost a lot.  In Hawaii where I live, an hour in a Robinson helicopter that’s had its doors removed, but not its pilot, costs roughly $350.  Not too expensive on the face of it, but it comes with some restrictions.  First, it’s only for one hour.  I regularly leave my KAP rig in the air for hours at a stretch, waiting for just the right light or just the right action.  Next, helicopters and airplanes all have to stay over 1000′ above ground level.  A KAP rig stays less than 500′ above ground level.  The views really are different.  And finally, three hours in a Robinson would pay off all of my KAP gear with change left over for making prints.

Top of the Lighthouse II

The second point in the previous paragraph, the one about viewpoint, is often lost on people.  If some altitude is good, wouldn’t more altitude be better?  If your goal is to look for camouflaged rocket batteries or some other secret military facility, sure.  This is why a great deal of the military’s reconnaisance is done from satellites.  But if the goal is to produce an intriguing photograph, more altitude often spoils the view.  If greater subject distance was always preferable, landscape photographers wouldn’t need wide angle lenses, would they?

Top of the Lighthouse I

Besides, the camera equipment necessary to render fine details from even a thousand feet away is not the most affordable, or even the most portable thing in the world.  I would argue that the previous photograph could not have been produced with a long lens and a longer subject distance.  But even if it could, without a stabilized camera platform and a truly remarkable camera and lens, the level of detail avaialble from such a photograph would not be all that impressive.

Too Close for Comfort!

It’s one thing to stand at the base of a lighthouse and wonder what it looks like on top, and only be able to satisfy your curiosity by driving to an airport, renting a helicopter, convincing the pilot to fly to the lighthouse, and only then find out the answer.  It’s quite another to reach into your backpack, pull out a kite, line, and rig, and by golly find out right then, right there.

Why take pictures from a kite?  Because I can.

Green Sand I

— Tom

The photos used in this post were all taken from a camera suspended from a kite line during World Wide KAP Week 2009.

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