Thursday, January 13, 2011

HOWTO take a million digital still photos

I have 3 reasons for creating videos as big sequences of still photos. My current camera does a good job but it is slow and I want to replace it. DSLRs and EVILs appeal but there are shutter life issues that are very difficult to get information on - after a lot of digging I have decided they cannot deliver. Webcams have been improving so I plan to go for modifying webcams to meet my main need of film digitisation.

3 reasons why I want to take a million photos per year.

1. (Main) is digitising film to video by individually photographing every frame.
Ref: "What's up with Film Digitisation?"
My test result then was - to copy Super-8 film frames at near full quality needs a sensor of at least 1280x960 pixels.

2. Physical object animation aka "claymation"
Ref: "Dancing with the Pollies"

3. Time Lapse

Current solution - Panasonic MX500 Video Camera used as a stills camera.

This has a non-interchangable zoom lens which takes well to adding other camera lenses as close-up lenses because of the very small sensor size. The sensor is a 3CCD unit which gives a better resolution than the size would suggest. Panasonic claim a relatively high 2.3 Megapixel stills performance compared to the 0.3 Megapixels for video by half-pixel-offsetting of the 3 CCDs. I was sceptical of this but my tests with line resolution charts indicate that the offset does work.
This Panny delivers excellent results but it needs 10sec between still shots which means 10 hours to digitise 1 x small roll of Super-8 film.

Investigating possible improvements:

DSLRs and EVILs? No because they have a mechanical shutter.

My investigation began with the Canon EOS DSLRs including hiring one for a few days to try it out. Excellent cameras in many ways but not for this particular job. Even in electronic "live view" mode a mechanical shutter gets in on the act to take a still photo. Further investigation reveals that other cameras including mirrorless ones also have a mechanical shutter - eg Panasonic Micro Four-Thirds.

Aiptek GVS? No because sensor/lens geometry is too big

My favourite budget cam, the Aiptek GVS, comes close. GVS comes with a charger that doubles as a long-run power supply. It has remote control. But the physics of a zoom lens limited to 5x with a relatively large sensor makes it more difficult to get the ultra close up shots of Super-8 frames. Maybe a goer if I could obtain a stills camera lens of 28mm focal length and aperture f/1.8 or better to use as a close-up lens but that includes the negative factor of adding extra glass to the mix.

High Definition Webcam? Looking promising!

My next experiment is to buy a high definition webcam and modify it. If I can remove the lens then I could substitute a single prime lens from a 16mm camera. I have bought this:
It has recently arrived and on early testing is looking promising. Its own lens simply removes by unscrewing giving good flexible scope to use it with other lenses. The sensor on my testing gives results true to its claims of 1600 x 1200 pixels which is a good size for what I want to do.