Aerial Photography

I hope my choice of font for the headings isn't too subtle for most. Anyway, if you haven't all ready guessed, this is my aerial photography section. What is aerial photography?  Glad you asked. Well, the first word, “Aerial,” by definition is “in or belonging to the air or operating (for or by means of aircraft or elevated cables) in the air.” And, I'm sure you know the word “Photography,” which is the art or process of producing images by the action of light on surfaces sensitized by chemical processes. Whew… So, what does that mean to us, and this web page? Well basically I strapped a digital camera on a model airplane and took some pictures while flying.

You can click on any of the pics to get a larger, clearer version.

My Setup

I was bumbling around one Saturday afternoon in a Target store, when I entered the electronics section. I did my usual looking at PS2 games, and then wandered towards the memory cards to see if I could find a cheap one for my digital camera. On the way there I noticed some one-time-use cameras and some cheap digital cameras(I am always looking for a cheap hi-res digital to keep in my pocket all the time.) Most of the digitals took low res pictures, and were priced over $100. Then I noticed the Bell and Howell BH-21. It was only 60 bucks, and it tool 640x480 pictures. Not great, but not bad. That night I went home and did some research on the web for the camera. It seemed like an ok deal, and it was light; only about 2 - 3 ounces. Consequently, I thought, “Hmmm. Maybe I can put this on a plane.” I then took out my trusty ZAGI 400X and did some weight tests with a buddy of mine, Bill. We used quarters and weighted that sucker down almost five ounce before we could barely fly it anymore. This seemed great! So, I bought the camera. Here's what one looks like new. The only difference between mine and this one( As I lost the plastic shell for mine), is mine had grey instead of that blue.

The back is not that exciting, just a mode button, and an LCD number display. Now, I had the camera, but it needed something...less. I promptly unscrewed and lost the plastic case and looked at the guts. Sheesh, there's barely nothing there. Apparently most of the weight comes from the casing. Good deal!

The camera has this “feature” where it goes into standby after five minutes to save battery. You see, there is no memory card. It has an internal 8 Megs RAM that holds the pictures. And if it looses power, bye-bye pictures. So, it goes to this standby mode that saves on batteries until you either, plug it into a USB, or push the mode button.

Now, if you're flying, and trying to take pictures, how do you know if it went to standby or not? You don't. Hence, I needed a way to keep it out of standby. Well, as luck would have it, it doesn't go into standby when you have it plugged into a USB, because it gets power from the USB, and doesn't need to worry about loosing battery power. Next, I did a little soldering and viola, I hooked five volts to the USB connector, and.. It didn't come out of standby. DAMN! It would seem that the firmware of the camera actually needs a USB signal, and not just the power, to think it's on the USB. DOUBLE DAMN! So, being an electronics kinda guy, I get this brilliant idea that maybe it doesn't really need 100% USB capable signals, Maybe if it thinks something is trying to talk to it, it'll wake up and try to talk back. I then hooked a square wave signal generator to the signal line of the USB and fired it up. The camera sprung to life! Now, all I needed to do, was to attach the 10 lb. signal generator to the plane. Riiiiiight..... “New Plan,” I thought, “I'll build a square wave generator from a 555 Timer and hook it up.” It sounded like a good plan, therefore I began to build. Then, inspiration struck again! I remembered that the radio receiver for the servos uses a PWM 50Hz signal to talk to the servos. A little more soldering... I hooked a signal line from the shutter-switch-servo to the USB signal line and it worked great.

You can see from the picture below the three wires coming off the USB pads. The black wire is Ground, Red is +5 (from the receiver servo power), and the Yellow is the signal line toggling at 50 HZ.

So I got it powered! I then glued on a Cirrus CS10 servo - the smallest I could find. (I think Cirrus has a mini-sub-micro servo now called the CS-5.)

Now I turn on the plane and start snapping pictures.. It goes great! I turn off the plane and go to download the pictures... No pictures. DAMNIT, it lost power when I turned off the plane! To fix this, I soldered a 1/8 inch phono plug to old battery terminals. And I rugged a jack to a 3 cell AAA holder that I bought from the Shack.

The last issue was mounting it to the plane. I decided to use a Mylar anti-static bag taped to the wing for 3 reasons. First, it provides some aerodynamic-ness to the congloption. Second, It keeps out dust and dirt, and protects the electronics. Lastly, it has a resealable opening, so I can leave the bag taped to the plane and just pull the camera out. I didn't use a regular ZIP-LOC sandwich bag because it would have generated static electric, and may have damaged the electronics.

Lastly is operation of the camera. Below is the procedure I go through when I want to get some pictures.

1. Insert camera into Mylar bag.
2. Tape bag down.
3. Hook up Y connector to shutter servo, USB connector, and channel 5 Slot on receiver.
4. Turn on plane, fly it, snap some pictures.
5. Land plane safely. This is important
6. Unzip Mylar bag, and fish out the phono plug.
7. Connect up the battery pack.
8. Shut off the plane, and remove the camera.
9. Connect to USB cable that leads to my laptop.
10. Unplug the battery pack.
11. Download the pictures, and enjoy.

Notes

You may have noticed that the camera is taped to the top of the plane. This is no mistake in the photographs. If I taped it to the bottom, I wouldn't be able to land the plane without destroying the camera. My only solution then was to tape it to the top.

You may ask, how do you get pictures of the ground then? Inverted flight. I've gotten pretty good at it, pictures of the horizon aren't too hard. But the pictures of the ground can get tricky because I have to fly inverted to get them.

My buddy Bill used my experience, in this venture, for his plane camera. The main difference is he cut through his wing, and implanted the camera into the foam. He put a small piece of clear plastic on the bottom to protect the lens while landing. I was jealous of his setup until he flew it... hehe. He used an old receiver that doesn't work too well, and he ends up loosing his pictures half the time. So, mines harder to fly, but reliable, his is easier to fly, but not as reliable.

And, as always I am looking for a light hi-res camera for flying, and for my pocket. Lately I've been looking at the MDC4000 made by Mustek. Or at least I was. My aunt bought the MDC5000 which is a step up in megapixels, and the camera, while light, is a piece of crap. So the search goes on...

The Pictures

I put my aerial photo's in the Pictures section of my website.