It seems that a good practice is to aim for a 50 to 60% histogram reading using the ASI224MC for planets. But which color do you use? I hav every different histograms readings between R, G, and B. I find the Red color may read 50 to 60% but green will be 40 to 50% and blue may be as low as 25-30%...this is for Mars BTW.
I'm thinking you use the Red (or the highest color) or does it matter that much?
P.S. I do have a UV/IR block filter in place.