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I started flying movie cameras around 1990 and my first attempt was a disaster. I was modifying Super 8 mm cameras and I knew if I increased the voltage to the motor I would increase the frame rate. This would provide a slow motion effect when it was played back at normal speed. It also increases the shutter speed. I decided to remove the automatic aperture to allow greater light (because of the increased shutter speed). Then I decided to use fast movie film (ASA 160 which is no longer available). I made all of these changes without fully understanding the relationship between them. The result was an overexposed footage with images that could barely be made out.
I put away the movie cameras for several years. One day I tried again, this time using my knowledge of cameras, film, and how to properly expose the film. I was using 40 ASA film and with the aperture control removed the lens was an f1.8. I figured the shutter speed I would need for correct exposure would be about 1/2000th second.
I measured the frame rate of the camera and it was about 50 frames per second (fps). That means that the rotating disk used for the shutter would have to be 1/40th of the disk or about a 10° opening. I was very surprised to find the opening in the rotating disk was about 220° or 1/30th second. No wonder I overexposed the film!
If you’re thinking about flying a camera rocket you may wish to consider a Super 8 mm movie camera. The inside of the cameras are more mechanical than electrical so it doesn’t take a degree in Electrical Engineering to get it to work. There are advantages and disadvantages to flying a movie camera. The cameras are very cheap. Since the days of video, there is very little demand for movie cameras. You can buy the cameras for usually only a few dollars. The film usually costs more than the cameras. Plus you have the cost of developing and then transferring it to video if you prefer. You can buy used projectors for a low price, again very little demand, and your run time is limited. Typically, one 50 ft cartridge lasts just over 3 minutes at 18 fps and you may only get 1 to 1 1/2 minutes.
To me, the biggest advantage is increasing the speed of the camera and playing it back at normal speed gives clear, smooth, slow motion images. Many people ask me why I don’t put video cameras in a rocket but to me there is no comparison. Video cameras have been getting better but they still suffer from many disadvantages. Many video cameras still jump and glitch at high g’s or at parachute deployment. Many have slow shutter speeds or require slow shutter speed for the amount of light needed for the video sensor thereby giving you blurry images. And unless you pay major money for specialty video cameras, the only way to get “slow motion” on playback is to literally slow the rate at which the frames are played back. With high speed movie cameras the images are recorded at a high rate so the playback at normal speeds is already “slow motion”!
Recently I have been flying high speed 16 mm movie cameras that were made to run from 64 frames per second to 400 frames per second! The results are crisp, clear, images. Of course you don’t get to record sound with these cameras but that too can be recorded and added at a later time. Best of all, if I want to watch it on video, it can always be converted! But I prefer to watch it on the big screen. The list of cameras here are some of the more common cameras I use for high speed recording.
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