Very cool. I like the vertical black lines, it looks like a film reel from an old movie that has been scratched going thru the projector.

Wow, that is all very valuable information, thank you. I feel a lot more confident attempting the surgery on the electronics now.

I had a thought about going from bw to colour. If should be possible to capture the same scene 3 times, each time with a different colour filter in front of the lens. Then merge the 3 images together as colour channels in Photoshop or similar. The filters will reduce the amount of light picked up by the sensor, which will help a bit on bright sunny days, but will require more light in a studio. Also, in a low light situation, it could be possible to capture a fourth scan with no filter, and use it for brightness information. I'm not exactly sure how to do that, but I know some cellphones use that trick.

Edit: But I also like your idea of tapping the signal to trigger external lighting.

I love your post, I've been thinking of ways to capture images from large format lenses, and you inspired me to start experimenting with flatbed scanners.

I'm using a Canon N 650U because I had one lying around. I haven't modified it, so the light source still exists.

I'm genuinely surprised how easy it is to get an image. I experimented by putting the scanner directly under the ceiling light in my kitchen, and I can hold the lens over the flatbed and see the image forming well enough that I can get it into focus. Then just hit the scan button and tada, one image of a ceiling lamp. I didn't need to dismantle the scanner, or use a gg screen or anything. It just works with the scanner and the lens.

Since then I've rigged up a system to hold the lens in place, and a slider to move it up and down to focus. And I drape a cloth over everything to keep stray light off the sensor.

Exposure is difficult. My large format lenses don't have any aperture control, so I either have to build one, or use an ND filter. Or if I don't have enough light, I add more continuous light sources.

I saw your comment about vignetting, but I didn't understand it at the time. I've mostly been experimenting with a lens that creates a 100mm image circle, and it works fine. But with another lens, I've just tried to scan the entire A4 surface, and the corners are black with a small image in the centre, even though I can peer under the curtain and see a nice bright image from the lens that covers the whole flatbed. I concluded that the sensor will only accept light from one direction, and can't see light arriving from an angle. So, yeah I'm considering surgery to fix the aperture slit in front of the sensor. I don't really know what to expect when I open it up. Did you find it easy to remove and modify? Can you offer any advice before I get elbow deep in scanner parts?

Also, my images all come out in black and white, which is weird. Objects sitting on the glass come out in colour, but the image formed by the lens scans in black and white only.

The whole rig is too heavy to pick up right now, so I mounted a little mirror on top, so I can point it anywhere, lol.