Author Topic: Decapping and Chip-Documentation - Howto  (Read 4937 times)

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Online magic

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Re: Decapping and Chip-Documentation - Howto
« Reply #75 on: August 17, 2020, 12:37:00 pm »
I think some 3D printed casing would improve the quality a lot.

For real photography time is probably better spent figuring out how to put this (or a better?) beamsplitter between a real microscope lens and a real camera.

Better construction would improve flatness of focus (I think the bottom right corner of my 5532 image is a bit soft, for example), hopefully uniformity of brightness, and maybe contrast a bit. But you are still left with a high crop, low resolution and noisy sensor, questionable demosaicing (regular dot artifacts appear in a few places on my shots) and auto white balance and sharpening that cannot be controlled. My webcam also lacks manual exposure mode so it can't even be used for panorama stitching.

I made this webcam mod to test the beamsplitter concept and for direct inspection and reverse engineering. If some corner is a bit out of focus, I will simply move the camera or tap my finger on the PCB to realign it. BTW, a big nuisance is the USB cable which pulls on the board. I tried stripping the last 10cm of external jacket and shield or using a piece of ribbon cable for the last 10cm but this breaks high speed USB.

The lens is close to its limits too. I estimate my resolution at about 0.5µm/px and an f/2 lens resolves maybe a line pair per 1.5µm so I'm already sampling at 150% Nyquist density. Maybe some minimal improvement could be gained by doubling the pixel density, but beyond that there is no hope without a better lens.

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