July 16, 2003
KAPs of our Innocence
As I occasionally do, I spent this evening picking through cardboard boxes sloppily crammed with bundles of photo negatives. I would like to bring it to some order, but the photos arrive far faster than they get sorted. I did a very crude categorization of the photos I took between 1999 and 2002. One of the categories was Kite Aerial Photography.
Below is one of my favorite shots, scanned at 4000dpi, cropped and adjusted, and ultimately reduced in resolution and size. Still looks pretty sharp. Also, I post a zoom-in which demonstrates how much detail the scanner can actually pull up from this scratched negative. (Thank God for the Clone Tool and Healing Brush)
The funny thing about these photos is that they are among the best we took in our many flights, but actually, the rig was a version 1.0 model, with no aiming system and some really kludgy gearing.
The photos were taken along the Pacific Coast, south of Half Moon Bay. 31die always liked to take the backroads from Palo Alto, over the hills, to the coast.
April 15, 2003
KAP Rig todo for Outback2003
From 31die:
Here's an initial, overly ambitious, list of KAP revisions:
* Get a replacement spar for the heavy-lift kite
Spar is 77" long, 5/8" square hardwood. Might make sense on this
one to call "Into the Wind" and see if I can just buy a replacement.
Mike -- this kite is/was available from them, wasn't it?
* Move the camera TX unit back the pan-tilt assembly
Putting it on the picavet created a lot of grief, even if it did
help the range.
* Look at changing the pan servo to use a servo-city gearbox.
We'd have to check what the weight looks like (probably minimal) and
if it gives us the range of motion we want. I think the problem
with it is that it offers the same range of motions as before (120
degrees or whatever you nominally get from a servo) with more
torque, lower speed. The torque/speed change is useful, but we also
want to get to > 360 degree rotation. What I'm looking for here is
something that is an all-in-one solution, so we don't have to screw
with the external potentiometer again.
This change may be in the category of needless -- the current
solution does work, although it is mercurial. Camera TX improvements
are probably more important.
* Change camera TX patch antenna (mickey mouse ear?) to optimal
coaxial stub
I think this is a definite. The only thing I'm worried about is
that the web site made a lot of noise about this modification being
very sensitive to getting the dimensions spot-on. I don't know if
the people having trouble were off by some gross error, but I doubt
my ability to any better than they did. I can do experiments to
figure out of I've made things better/worse, but I wouldn't know how
to improve the result, short of just going back to the old antenna.
* Add amplifier to camera TX unit
I think makes a lot of sense. The risk here is that involves adding
something without damaging the TX circuit. Presumably if I'm
careful I can manage this task.
* Unify power supply with radio RX
This is already done on the current version. The camera TX battery
box is 6V, so I put a tap on that to run the servo RX
* add DC-to-DC power regulator
This would replace the probably very shitty DC-to-DC regulator
included in the camera TX box. Probably necessary if I add the
amplifier to the camera TX -- the existing regulator likely doesn't
have enough power. This is kind of an annoying job -- a handful of
little components. There are plans on the web for it though, and it
should be manageable.
* replace XCam2 CCD with high quality CCD
At least one guy recommends a $100 Panasonic CCD -- apparently the
CCD has much faster response time (so the camera won't get blinded
by changes in orientation to the sun) as well as a better lens. The
XCam2 lens has huge amounts of distortion. I'm not sure about this
mod -- I think it might be in the category of "getting more
expensive faster than it is getting better." I'll think about it
some more.
* camera RX power supply
The current camera RX power supply is an 8-pack of AA batteries.
I'm not sure that these necessarily provide enough current for it.
Something beefier would probably be good, although I don't really
know what to do here. Could just go with C batteries instead of AA
batteries. Could introduce a 12V nicad, which would need a charger.
* camera RX antenna
The RX antenna probably needs as much improvement as the TX antenna,
and since it doesn't have to fly we can do something more
aggressive. There were plans for some sort of antenna that's
supposed to work much better. One issue is I think the result is
more directional. This could be okay, or it could be a pain.
Presumably the kites macro-scale direction changes pretty slowly,
assuming the camera man is standing in the same area as the flyer.
* ground unit display
It would be nice to have a bigger ground-unit display than the
CamCorder's display/viewfinder. Issues here are that it would need
to still be visible in bright sunlight, which generally seems to be
the kiss of death for LCDs. Maybe a small CRT?
* more kites
We very rarely have trouble with too much wind. A kite that's
compatible with low winds and docile, etc. would be a useful
investment. I think the thing here is a parafoil soft kite, but I'm
not sure.
Looking over the list, I think all of these make sense to do, with the
possible exception of the servo-city gearhead fo the pan-axis, and the
replacement CCD. I'll start putting together a list of materials.
March 10, 2003
RC Technology for the KAP Rig
RC-CAM4: TINY R/C MODEL CAMERA SYSTEM, Page 3
This should help with some of the aiming-camera problems we've had with earlier versions.
March 03, 2003
February 16, 2003
KAP Rig Improvements
Over Christmas we also brainstormed about avenues for improving our Kite Aerial Photography system...
- Several kites appropriate for different wind conditions (parafoils, etc)
- Digital Camera instead of 35mm.
- Aluminum rig -- stronger, lighter, tidier.
- Unified power system. Get rid of the excessive bricks of batteries, strange transformers, etc. Maybe even use those one-time-use military lithium batteries.
- More powerful transmitter. Makes the viewfinder image more usable.
- More sensitive, directed receiver. Makes the viewfinder image more usable.
- Tripod-mounted base-station. Allows one person to control rig, watch the viewfinder, and shoot photos.
- Better vibration isolation for (a) line noise (b) servo-induced shaking.
- Weather balloon booster. More lifting power, also maybe less vibration?
October 29, 2002
Aerial Platform Discussion (pt 2)
[from an email discussion with 31die]
Having an aerial platform really would be tremendous. I'm trying to
think of other ways to get something airborne.
How about with a winch, like they use to launch sailplanes? If you
use it to launch a glider holding a camera then it is a big & heavy
glider. If you use it to launch a kite, then the assumption is once
you get some good height there will be stable wind available.
How does a winch work?
Dirigible of some sort? This could actually be okay, assuming it is
not powered by a burner, but is lofted by helium or something. I
guess the problem becomes it will take a large volume of helium to
launch our apparatus, and when you retrieve the thing it seems dubious
that you'd be able to pump the helium out of the sack and back into a
storage tank.
Weather balloon? That might also be viable. I guess that is the same
as a dirigible -- with the advantage that it is meant to loft
instruments, will be more robust than some air sack we build by hand,
etc. I think they are all launched on helium.
Yeah, I have thought about this option before. But my idea was to supplement the kite's lift with a weather balloon connecting to the same point on the kite line that the upper arm of the kap bridle connects too. My thought was that this would reduce the apparent weight of the rig while allowing it to otherwise behave the same to the kite. I also thought it might provide sort of a buffering to the whole system and make it slightly less jerky. (though that might be uncompensated for by the wind blowing around this big fucking weather balloon)
But furthermore, this becomes less realistic when I point out something I read the other day. The USA basically holds some staggering fraction of the world's supply of helium. While it's available everywhere in the usa, apparently it is harder to come by elsewhere. I suppose you still must be able to get a cylinder of it for welding gas purposes in australia? In fact, if anywhere else has helium, it would probably be ore-rich Australia.
I was entertaining visions of a land cruiser racing across the outback with a 5-foot diameter weather balloon in behind the rear window, out of the wind as we drive on to the next site.
hmm. I wonder how sophisicated, expensive weather balloons are. I bet google knows... It tells us how many balloons per cylinder = f(ballon size, and cylinder size). It tells us how to fill a weather balloon. It tells us what to do if you find one (plus some manufacturer names) like Vaisala, VIZ, AIR. This site has tons of links to miniature hot air balloons, which I have built many times, and which I am being expressly forbidden from purchasing by my skeptical wife, but there may be some links to where to purchase weather balloons. It's getting late; I'll have to dig later. AH-HA! WE'RE IN! HERE THEY ARE!
*followup: there is also this odd site referring to pibal analysis.
Model rocket? They used to sell a rocket than had a tiny camera in
the nose cone. When the engine burnt out the rocket would start to
arc over in a parabola and the slight offset mass of the camera would
make it face the earth. I don't know what determined when the shutter
fires -- if they were clever they could detect the momentary
weightless at the very top of the parabola and hit it then. Of
course this has no video, etc.
hahahahhahahahaha I think Australia has sensitivites regarding open flame in the outback.
Ultralight?
Parasail?
Would be damn cool.
Enormously long pole?
I myself was wondering how interesting a perspective it would give our photos to have a 20' or 30' high pole to take photos from. What is the largest free-standing pole we could carry and deploy? My guess is pretty fucking high, especially because we'll have two landcruisers and winches to manhandle the columns. IP built a 80' high one from sewer pvc pipe. All it needs is some hole in the ground to fit into, and then hoist with a triangle.
Digital KAP?
If you read our kap changelog, you'll see the refinements are to provide video aiming system for our yashica t-5 point-and-shoot camera.
I'm sometimes disappointed with the camera because it suffers from vignetting. (not a specific fault of the t5 model in particular, it's a very good camera, but just a fundamental problem of most point-and-shoots that have a radial iris) My other complaint is that it's a fixed 50mm lens. 50mm is the same angle-of-view as a human. When the camera is two hundred feet up, 50mm field of vision is enormous and subjects on the ground are tiny. You don't use a 50mm camera to take landscapes (well... you might, but they suck). It might be nice to get different perspectives by using long lenses, more like a hawk's view, or even very wide lenses, like an airborne fish. None of that is possible with the t5.
We need the aiming to try to ensure that we don't fire off a roll of 36 shots, and have none of them be worth a damn. We mis-aim, there is too much motion, it's too dark, we're too high, too low, and on and on and on. There are endless reasons why kap photos often suck, and must have among the worst ratios of good photos:crap photos per roll. Additionally aggravating is that you don't get to see your results until well after your trip is over. I'd say so far our kite photos have only been perhaps 10-20% as pleasing as we'd have liked them to be.
Our video aiming system is rudimentary, insofar that the video requires an video camera, transmitter, power in addition to everything the camera/rc rig needs. The 2.4ghz transmitter is only marginally good enough -- often swinging or swaying out of range or out of the aim of the sensitive little antenna. It certainly helps our pictures, but it introduces its own problems, and isn't very refined. It takes the entire concentration of two people to run this setup.
So I was browsing some kap sites last night, and saw that the infamous Charles Benton is now using a digital camera. Now this guy truly does have a staggering library of excellent kap photos. No question about it. I always thought he was the purist -- sticking it out with 100ASA 35mm slide film and so on. That he was using, and raving about, a digital camera got me considering if this might be an angle for us to consider.
"Should we switch to using a digital camera instead of the 35mm yashica, perhaps even dumping the video aiming system, too?"
Well, only if two things are true:
1) that a digital kap rig can improve our chances of "getting the shot"
2) that the one-in-a-thousandth shot that is truly superior can be rendered as an art-quality image
What technical requirements would the rig and camera need in order to say "yes" to those questions?
a) We need some metric for the measure of image quality we need.
...How about, the image comes out w/ enough color and detail that it could be blown up to an 8x12" photo? {bigger?}
b) Dimensions and weight
...would be nice if various lenses were available?
...would be nice if it were <= weight of current system
c) Storage capacity
...if you could fire off enough photos, you could eliminate the need for a video aiming system entirely?
...IE: tradoff accuracy of a single photo for the chance to fire 100 unaimed photos instead?
...IE: tradeoff video-aiming-system weight for increased weight of better or varied lenses?
d) Kap-specific functionality the camera would need
...electronic firing, instead of a crude mechanical shutter finger
...do any cameras output an image signal that could be transmitted directly back to ground station ?
...IE: use the camera as an integrated system for both aiming and taking photos.
October 27, 2002
Our Outback 'Aerial Platform Requirements'
So we'd like to do kite aerial photography during our trip through the Outback. Of course, the wind is fickle, and at least several times we've been reduced to dragging the kite through the air with our 4x4 or Lincoln Continental. What if there was a better way? Not only could we get well-framed, sharp 35mm photos of ground subjects, but we could do live recon of the areas we were exploring? It sounds like our expedition has a serious aerial platform requirement!
One thought is always the trusty RC airplane. They come available in less-messy electric engine versions now, and of course people have fitted them with cameras. Plenty of people have investigated this technique. I would say, however, even with the simpler planes, they seem terribly difficult to fly in-general, let alone with purpose -- like flying as navigational outriders for our 4x4 convoy. What you really want is a big, slow, stable brute that can loiter over targets while you photograph or send back live video.
A really slow, stable platform is, of course, a helicopter. [ed: of course there are RC Airships as well. But don't bother the author because he is a very busy man.] Now if you thought flying an RC plane was hard, how about an RC helicopter? I knew a guy in university who had one. From what I could tell, flying the thing is basically impossible. I saw him once or twice "fly" it about 18 inches off the ground and then bounce back down. It didn't destroy itself only because there were enormous supplemental landing bars that prevented it from careening onto its side. It looked like a huge, expensive, frustrating pile of shit. At all other times it looked quite smart as a bookshelf trophy. But be clear... it never, ever flew.
Well, almost ten years later the New York Times talked about a new breed of helicopter machines that used sophisicated gyroscopes to make flying helicopters enormously easier.
The base model, the Draganflyer III, is a simple gyro-stablized indoor-outdoor helicopter. Reading about the $750USD machine almost immediately disqualifies it from field service. Flight time is 5minutes. It can't fly in wind > 5mph. It "generally" can lift the weight of a 2.4ghz wireless camera system (which is a trivial weight and trivial quality). The crash kits of blades and carbon rods are $150 and their wireless video system is another 200$. Definitely not suitable for hauling around a 35mm Yashica T5.
But Draganflyer offers what they promise to be the solution to your 'aerial platform requirements,' the Draganflyer Xpro. This monster is designed to carry one pound worth of video/camera gear. It's still strangled to about 5 minutes of flying time, which might be ok for a bit of Aerial Photography, but this will never be our drone outrider. One other problem is that the thing costs five-thousand dollars. Yes, $5,000. That is far beyond any fathomable impulse depth for me, especially since the thing isn't even ideal. Figure $5000USD = $9000 Australian. I think I could buy an awful lot of bush-pilot time for 9000$ in the Outback and probably get some very stunning photos, as one obvious alternative.
So, basically, I dunno. It appears that having a menagerie of kites for various wind conditions, and maybe spending some more resources miniaturizing the KAP Rig itself would be money much better spent in an effort to get good, sharp aerial photographs of the outback. Unless Draganflyer wants to donate me one of their monster machines, it's a dead option hovering. I think dirigibles are doomed by physics. The last option is to look into getting an rc plane outfitted with some gear. I think this is easily an order of magnitude more feasible than the helicopter, but probably still an awful lot of work. It's one more avenue to investigate, though.