[Tig] Subject: Re: Scans from different scanners
richard at filmlight.ltd.uk
Sat Nov 22 10:02:23 GMT 2014
The Northlight scanner was designed to measure RP-180 primaries. This is a Kodak standard very similar to Status A. One or the other is the logical choice when designing a scanner to measure film negative. If you change a lamp, the spectral sensitivities will change slightly, but this is little more than a shift in the R-G-B balance and is largely compensated for when the scanner is white balanced. If you put the same original in different Northlight scanners you may see slight differences, but this will not be significant with camera material as the images have not been graded yet.
If you want to be more precise, it is possible to scan a Truelight test strip, and then make a calibration from the scan and the corresponding densitometer measurements. Or you can put the same strip through two scanners and make a transform that should match one scanner to the other. I don't know if anyone outside FIlmLight has ever done this, but the tools are there if anyone wants them. Personally, I would recommend doing without and living with the differences provided they are small. In general, anything you do to the scanned data, including sharpening or noise reduction will potentially do some harm.
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