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What's the easiest and most affordable way for obtaining UV reflectance images?

Started Apr 24, 2021 | Questions thread
ProfHankD
ProfHankD Veteran Member • Posts: 9,147
Old EPROM as UV imager

Enginel wrote:

ProfHankD wrote:

Yup, quartz lenses are the "right answer." That's why old EPROM chips used to be so expensive: to get enough UV to erase 'em, they needed a little quartz window and a ceramic package to mount it in.

Has someone crazy enough used them as an image sensor?

Not that I'm aware of... which I wish you hadn't said. 

It takes A LOT of UV to erase a bit, so exposure time would probably be days if not weeks of sunlight, and without a quartz lens to focus the light, I'd probably try a pinhole, extending exposure time into months. However, I will admit that I kind of want to try it now. You should be able to get a huge DR by sampling over time to watch when each bit changes... except I don't think lighting really comes with a huge DR when averaging over a month....

BTW, an early digital camera, the Connectix QuickCam , actually used a RAM chip that had be specially packaged with a glass window. I still have my parallel-port-interfaced Color QuickCam somewhere.... In fact, in 1996, that was just about the only live view camera ("webcam" wasn't yet a thing then) I could hook-up to my 6400x4800-pixel cluster supercomputer-driven video wall, which was a little sad, because it delivered 320x240 images with somewhat wonky color.  Then again, it was the gross inadequacy of that which got me started doing computational photography... so I guess it was a very good thing in the long run?

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