I thought maybe I had a solution to the Leica M240 green shadows problem. I figured, if it is a result of the M240’s nonlinearity in dark tones, then I could put a filter on the lens so that the green channel didn’t outweigh the other two. If they all rolled off together, the darks would be a bit too dark, but at least I wouldn’t get a color shift. I tried a CC30M, and found that the results, while somewhat improved, were still problematical.
I looked at the raw files and found that the green channel was still higher than the other two, although the red had come up some and the blue had come up a lot (this was in reflected, diffuse sunlight). It sounds like I’m on the right track, but a stronger filter will swallow up even more light than the CC30M, and this is about low-light performance.
Back to the drawing board.