Originally posted by Lord Lucan @photoptimist - some interesting links and good points there :-
The Silicon Film Technologies page says "connect to your PC or Mac for instant viewing, electronic storage ...[etc]"
That shakes my confidence straight away if they regard that as an achievement to be fan-fared as their a second bullet point rather than just a mention in the detailed spec - it really should go without saying.
LOL! Well it was the year 2000 and I notice that the page with their demo video has a version of the video optimized for 28.8 kbits/sec modems!
Originally posted by Lord Lucan I admit I was not aware of the glass thickness issue. You could however make a slightly smaller sensor (say APS-C size) that projcted forward a little in the film gate to get the correct register distance.
The "small protruding sensor" design seems to be what Silicon Film Technologies did. Whether that protruding sensor would hit the flying shutter curtain or blades is another matter. There's not a lot of room in the film gate.
Originally posted by Lord Lucan Again, I was unaware that a DSLR sensor was switched on (and off again?) as the shot was taken; I had assumed it was on all the time that the camera was (like film was always sensitive), otherwise what does the physical shutter do? Anyway, that being the case, how about using the flash sync socket on the camera body with a lead to tell the digital back when the mechanical shutter was fired? Or even put the shutter release on the digital back with a cable release going to the camera's shutter button?
The difference in battery life between mirrorless and DSLR is partially due to this issue. A DSLR sensor can be off almost all of the time up until just before the moment of exposure (that also keeps the DSLR's sensor cooler which reduces image noise relative to "always on" mirrorless camera sensors).
When the user hits the shutter button on a DSLR, the camera turns on the sensor and prepares it to take an image. But to get a clean image, the camera must reset the sensor to clear any electrical charge that's sitting in the pixels. All that must happen AFTER the shutter button press but BEFORE the shutter opens. Your cable release design would certainly work.
Unfortunately, the standard flash sync comes too late in the chain of events (unless the digital cartridge only supports 1/1000 sec shutter speed or faster). Using FP-sync (assuming the camera has that) would work because that sync signal fires before the shutter opens to give FP-sync flash bulbs time to fire and get to full brightness.
A second minor issue is that a digital film cartridge has no way of knowing when the exposure is over. I'd imagine that the default setting would run the sensor for a bit more than a 1 second exposure to ensure that the sensor did not stop recording the scene before the shutter closed (assuming the film camera' shutter speeds are 1 second or faster). Supporting longer exposures might use a "bulb" mode setting for the film cartridge that requires a second button press somewhere to end the exposure.
Originally posted by Lord Lucan I think that getting a digital back into the envelope an existing film camera body is an even more pointless challenge than making a digital back for it at all. It used to be considered cool to carry a film camera with a massive motor drive attached, even if you did not need it. Now the hipsters are demanding that the minimal envelope is maintained even if there were a real need to exceed it!
I am not advocating a digital back for film cameras; it is just interesting to speculate how it might be done.
I don't want this product either but do enjoy the weekend noodling to think about the possibilities. The only feature I miss from a film camera is the spot-metering system on the Olympus OM-4 that let you take multiple spot readings, showed those readings on a clever bar graph, and took the average. It was fantastic for metering the dynamic range of a scene and setting the exposure relative to the "whites" and "blacks" of the scene.