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A modern 35mm film scanner for home

(www.soke.engineering)
251 points QiuChuck | 2 comments | 11 Nov 25 19:48 UTC | HN request time: 0s | source
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gtm1260 ◴[11 Nov 25 21:21 UTC] No.45893048[source]▶
The fact that there is still no sample scans has me heated - instead of showing us all these specs, how about some sample images!!
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anonymousiam ◴[12 Nov 25 00:15 UTC] No.45894734[source]▶
It doesn't seem to exist yet. The specifications are not specifications, they are design goals. I don't see how they can get the color coverage they're claiming with RGB LEDs.

Seems about as credible as a lot of the crowdfunded stuff.

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atomicthumbs ◴[12 Nov 25 01:43 UTC] No.45895442[source]▶
The Coolscans used RGB LEDs.
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ChrisMarshallNY ◴[12 Nov 25 02:27 UTC] No.45895730[source]▶
Can confirm. I used to write software for them.

The issue with LEDs, is very pure colors. That’s actually a bit of a problem, with film scanners. You need a smooth curve, and it needs to extend out a bit. You don’t want areas of color being missed.

The Coolscans had a light color response (think the “levels” screen, in Photoshop) that looked like three steep hills, with minimal overlap, but they were able to make them wider than a “pure” LED. Coherence is a feature of LED lighting.

Most previous light sources used filters over a white light, and they looked “sloppier,” with a lot more overlap, so there was more coverage. We had to correct for the unusual color coverage of LEDs.

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1. formerly_proven ◴[12 Nov 25 09:26 UTC] No.45898104[source]▶
I assume the LEDs were matched to the typical pigments used in films though? Because otherwise metamerism just wouldn't work, RGB mixed to some CCT is not white light and can't illuminate arbitrary pigments with any kind of good color reproduction.
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2. ChrisMarshallNY ◴[12 Nov 25 11:48 UTC] No.45898997[source]▶
I assume so. The folks that designed the scanners were no slouches. I suspect that they never completely turned off any LEDs, so there was always some deliberate “slop.” With LEDs, however, you can explicitly control that. They probably had some kind of filter, also. I never took one apart, though.

I got the response curves by feeding in a special slide with a diffraction grating.

The curves were markedly different from an incandescent light source.