↓ ↓ ↓ ↓ SUBSCRIBE:↓ ↓ ↓ Follow by Email↓ ↓ ↓ ↓

Tuesday, May 27, 2008

331

Pinhole cinematography.
Today I put my pinhole lens to use. I made it last night using an extension tube (to be able to thread it into a c-mount lens mount) and a small piece of aluminum from a pop can. I took the aluminum, traced the end element, drew where the lens will be, calculated where the centre of the circle was, pushed a pin most of the way through it, then sanded the back of it until the divit became a round hole. Today I put that pin hole piece onto the overhead projector alongside a transparent ruler to be able to measure the hole. It is about .33 mm wide. The distance from the pin hole to the film to be exposed will be about 23mm. The optimal size of the hole should be about .2mm, but I didn't want to redo it at this time for a factor of 50% (1/2 stop). Then I calculated the f-stop by dividing the focal length (23mm) by the hole size (1/3 mm) to get f 69. This is pretty close to f 64, the aperture of choice for the famous F 64 Group who shot a lot of pin hole photographs. Anyway, I mounted the lens and the animation controller onto the Bolex and shot a series of sequences of still life out in the very bright sunlight we had today. I shot at 1/2 second up to 3 seconds. However, I didn't mount the motor correctly (I can't believe I'd make such a novice error) so I had to re-shoot, shorter clips this time (50 frames of each, rather than 200-400). I processed it and am happy with the results. I think 1.5 to 2 seconds will be the best timings for it.That should mean it will take 45 minutes to an hour to shoot a minute of film, that is when the sunlight is as bright as it was today. Here is the clip, it was a negative but I've reversed it digitally. It is of small trees on campus with buildings in the background. The nature of pin hole cameras is for unusual depth of field (ie: things are in focus from close to far away):

No comments: