So, I re-installed the prism, luckily it just slots back in. I'm not sure if it helped at all, I still get the much the same result most of the time.

I did manage to get this result. It's black at the top because the lid was closed. I opened the scanner half way thru, and the scan turned white. Then I waved the torch over the sensor and got a definite zigzag. And there's a hint of grey in the middle, which is encouraging.

So, the sensor is still working, it's responding to light, just not in a usable way.

Ok, thank you.

I genuinely laughed out loud at the title. Well done :-)

Scanned with a modified N650U

@Leavingoldhabits Hi again, can I ask you some technical questions? I'm struggling modify my scanner. I've removed the clips holding the PCB, and I even made a test scan in that state, and it still worked. Then I spent hours milling out the pinhole array. But when I assembled it again, I get weird scans.

I have modified two different scanners. LiDe 110 - I get a tall narrow PNG file with some digital noise. I assumed I damaged the sensor, or a ribbon cable or something, so I shelved it, and looked for another scanner.

N650U - I took more care modifying this one. I get a full width PNG file, but it has a narrow strip of white on one side, and black everywhere else. I wonder if it is related to the initial calibration that it does before scanning. I left the LED in tact, but I removed the prism, so maybe it's lighting up just that one end of the calibration strip?

Did you have any calibration problems? Have you encountered anything like this? Do you have any advice?

Thanks

I stumbled onto another use for my contraption. I was invited to a life drawing class, and I'm terrible at drawing, so I replaced the scanner with just a sheet of blank paper, and I drew around the image that was formed on the paper.

The scale is limited by the lens I was using. These two are about A5, but I could have drawn them larger if I was sitting closer, or using a longer lens.

Lighting was an important aspect. The room was dark, and the model was under stage lights, and I was working under the hood.

I've always wanted to try a Camera Lucida, but it's difficult to justify buying the prism. Maybe I'll try some kind of teleprompter type setup next time.

That's caused by the fresnel lens. Its a cheap plastic one that I picked up at a craft store.

Photographic film

That was worth watching, thank you.

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.