Taken on a small group of Islands in the Oslo fjord, called Hvasser. A 15 meter peice of fabric playing in the wind, scanned right to left in 21 seconds. Got really lucky with the clouds this time, allowing a single beam of sunlight in as a highlight.
Thank you!
The n650u looks very similar to the lide 30, so I’ll assume that it’s more or less the same inside.
The sensor assembly is fairly straightforward. A plastic housing that gets pulled by a cord. Once you liberate the assembly from its track/cord/whatever is holding it and moving it around, you get to the good part.
The sensor itself, and the RGB LED that supplies the light is on a PCB that’s mounted to the plastic carriage from the underside, it’s held together by plastic tabs (it’s a few years since I did this, so the details might be off, but it wasn’t a difficult task). Use a sharp utility knife to cut the tabs and remove the sensor PCB. I’ve used strips of gaffers tape to put it all together again. The LED looks like a small white rectangle stood perpendicuar to the PCB, I simply broke it off. This makes the canon drivers throw an error, but VueScan doesn’t care. If you’re squeamish about actively destroying your scanner, you can probably figure out a way to cover it up with some tape or foil.
The circular vignetting you’re seeing is due to the pinhole array, it’s a thin black plastic strip with a bunch of tiny holes set in front of a slit, just rip it off, its either glued or welded in place, but I’ve never had a problem getting it out with some pliers. While you’re messing about in that area, get rid of the prism that spreads the light from LED as well, it probably won’t do much of anything if left in, but it feels better to remove it.
Once you run the camera in this state, you will discover that you get uneven exposure from edge to edge, a linear vignette perpendicular to the axis which the sensor moves. This happens because the plastic housing of the sensor is throwing shade. So use any available abrasive machine, and cut that housing down to its essential functions of holding the sensor in its place, and as a pressure against the glass plate.
Unfortunately I don’t have any large format lenses around, so I’ve stuck a magnifying glass to the front of my camera (you know, gotta keep it punk rock), but the way I handle aperture is by cutting holes into black cardboard (very thin cardboard) at about the size I think will work, and taping the hole across the lens. One of my goals with this project is to try make photography into a tactile, direct and intuitive process so I try to avoid unnecessary machinery.
The reason you’re only getting grayscale is due to how a CIS scanner renders color. During a normal scan, the RGB LED only flashes one channel at a time, and the driver figures out if it’s looking at the red, green or blue signal all by itself, and at the end it interpolates the data to render a full color image file for you to enjoy. I’ve been playing around with the idea of tapping the signal path and use it to trigger an external RGB lighting rig in a studio, to get full color images of models. But so far it’s only a funny thought!
And lastly, the sensor is exceptionally sensitive to infrared light, to the point that the heat from the internal electronics of the scanner causes streaking. I’m using a few pieces of carefully placed aluminum foil to shield the sensor in select areas, and that reduces the issue to a tolerable amount.
Good luck on your build! This project has given me a boatload of insights into both photography, electronics and computing, and I hope you will have a similarly awesome journey.
Edit: im happy to answer any further questions you might have. it would be awesome to see some shots once you get the contraption up and running!
@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
Hi!
I’ve only ever managed to get the lide30 to play nice. I have destroyed one 110 and two 220-scanners in my efforts to build a more versatile rig.
What happens if you drop the prism back in?
I’ve also speculated about there being som calibration and automatic gain control going on in these newer models. I believe it could be used to normalize the values coming off of the individual sensor segments.
On my latest attempt at a 220 scanner, I actually built a small dimmable LED circuit that I attached externally to try and influence the calibration I thought was happening, but there was a disappointing lack of results. Come to think of it, I still have that rig laying around somewhere, and the experiment may have been flawed, I’ll have a look next time I’m at my workshop. I’ll let you know what I find.
I know that rig is at least functional, as objects placed directly onto the glass renders crude shadows on the scans.
That’s the long answer, the short answer is no, I don’t have any tips, maybe aside from working on fooling the possible calibration somehow.
Ok, thank you.