Site Sponsor Robert Houllahan Posted October 12, 2022 Site Sponsor Share Posted October 12, 2022 (edited) 12 hours ago, Phil Rhodes said: One issue which springs to mind here is that this is, we're told, a scanner using RGB illumination and a monochrome sensor. Much as that's great with respect to getting no-compromise cosited RGB information, using LEDs to do this does raise a couple of concerns. There's a decent red emitter available, but most (not all) LED blue is more royal blue than the deep indigo we might prefer. Green-emitting diodes, in particular, are notoriously not a very deep green. I have never looked into this formally, but I would speculate fairly confidently that there are deeper greens in film negative than the green of the sort of LED that is likely to be used in this sort of application. For what it's worth, the filters on a Bayer or other CFA sensor also tend to be rather feeble and that's one reason Bayer cameras struggled for years to produce workably accurate colour, until people got smart enough to apply a lot of matrixing. This probably wouldn't ywork so well with RGB LED scans because the problem isn't solely that the green is unsaturated - it's pretty saturated - it's just too yellow. There is not much ability to fix this sort of thing in post. Does any of that make sense to anyone? 1. There are more expensive LEDs which are in the right color spectrum range for film scanning and also for LED high CRI lighting, so it is just a matter of cost and devices for the LED Lamp for any of these scanners. 2. There is allot Alooooottt of color channel cross talk with any Bayer mask sensor, the dyes used are not strong like a dichroic filter. So that is the big disadvantage with a fast CFA scanner, just like with the digital cinema cameras. A matrix or LUT or combo can tune the system back to better especially if the LED lamp if properly balanced for the film and the CFA of the sensor before a matrix transform is applied. Edited October 13, 2022 by Robert Houllahan typo Quote Link to comment Share on other sites More sharing options...
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