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I’m trying to create a bunch of .mspec images, and I have multiple standards that are different pictures of the same thing. I’m measuring 3 different saturation levels (90%, 27%, 3%), and usually everything works fine, but I occasionally get an error message when selecting the 27% standard (“This standard could be overexposed in the R channel”). However, when I compare them on RawTherapee, the error vs normal images look essentially the same. What did I do wrong? and how do I fix it?

All the contents of the micaToolbox folder were copied directly into the plugins folder, which I’ve seen you suggest as a solution to similar issues.

R channel overexposed error message
Cedric van den Berg Changed status to publish March 24, 2021

Hi Lilly,

If your standards are non-Lambertian, then having them viewed from different angles might result in them not having the same reflectance anymore, which, in turn, would make the toolbox note that your three standards are no longer on a straight line (i.e. the seem to violate the assumption of linearisation). That would be my guess as to why you might be getting the error? A way around it would be to only use two standards, or even just one (i.e. 90% and then use the ‘estimate black point’ function). But, bear in mind that, if indeed your standards are non-Lambertian, the areas of interest in your images will start to vary as a result of the variation in your standard.