Another profile quality test: xicclu -fif -g -ir profilemaker.icc xicclu -fif -g -ir lprof.icc xicclu -fif -g -ir argyll.icc Let's compare the gray curves. I don't think that the camera have so uneven response as in lprof profile characterized. There is the slightly better situation in argyll profile, but 33-step CLUT is excessive in this case too. You could try -qm and -ql parameters for argyll colprof instead of -qh. I have a question, may be there is colprof -r parameter is useful with values higher than 0.5, 2.5% for example? May be the profiling result will be more even?