Hello ArgyllCMS users, I am pretty happy with my sunlight camera matrix profiles. In sunlight/daylight and with appropriate white balance they give satisfactory accuracy (low delta Es) and the colours look good. In artificial lighting, my sunlight profiles are inaccurate and the colours can look bad. I am now making additional profiles for artificial lighting: tungsten and fluorescent. I can't get low delta Es from colprof however. What could be the problem(s)? Assume the input image and white balance are good. I am thinking that the white balance (equalizing of raw photo RGB) is not satisfactory to "correct" strange light sources??? So a more detailed look-up table model is required to accurately transform to the Profile Connection Space (I am using a ColorChecker SG with D50 reference data)??? I would like to better understand the limitations of camera input profiles with strange illuminants. Stephen,