Does anyone know of a suitable curve or preset for using colour (alright, color) neg in Lightroom? Making one for b/w was easy enough, but with colour there's the issue of the orange mask (which also varies between different film stocks).
Hi Alex,
I don't know if you can get a better source scan, one in which the mask color was removed by using appropriate (different) exposure times for the R/G/B color planes. By using a better/filtered lamp color or adjusted exposure times, the mask can be neutralized.
If you scanned source image still has a mask color, then it must be removed in postprocessing in linear gamma space, but that will have a lower quality due to underexposed Green and Blue channels or a clipped Red channel. Since LR Process version 2012 the tonemapping has become significantly non-linear which will cause problems if you try to remove the mask color. Therefore I'd recommend using the Process version before 2012.
Then use different RGB white points to neutralize the shadows (whites in the negative), and adjust the black points (the whites in the negative) for mask removal. Then invert the image tones, and tweak the tonecurves for a nice(r) roll-off in the shadows and highights.
It is very unlikely that a canned curve will do a good job, because the mask density varies per processing run of the films, and the Mask neutralization is essential
before inverting / correcting color and tonality, and
needs to be done first. Also the non-linear response of Process version 2012 will cause a nightmare for color correction, unless the mask was neutralized by scanner exposure first, as it should (to avoid noise issues and color correction problems).
Cheers,
Bart