Graeme, I need to ask a daunting question. The DTP94. You have one. You have code that drives it natively from argyll (dispcal), which I hope to get to try soon. But, for the moment, I need to ask the following: to your knowledge, is it possible, based on the information you have from X-Rite's SDK, to download a set of user correction factors in the instrument for the purpose of creating a custom calibration? Do we know, for instance, how the instrument responds to incoming light in relationship with its two factory-supplied (for CRT and LCD) and software selectable calibration tables? I am not sure that is considered proprietary information. The reason I ask the question, today, is that I have access to a spectroradiometer that I know could be used to derive custom correction factors for any types of monitors, be it LCDs or CRTs, for the DTP94 (and any other instrument, for that matter, once we figured out their internals). Sound like an awsome idea to me. The only problem I have is that I don't know how to relate the readings from the DTP94 to those of my spectroradiometer in the context of X-Rite's calibration scheme? I can always measure a set of stimulus, on my monitors, with both instruments and calculate a correction matrix, in Excel, that brings the DTP94 readings inline with my spectroradiometer. But that is of little use when using the DTP94 with dispcal, or other popular monitor calibration and profiling utility :( Hope you can throw some light on this. Regards, Roger Breton | Laval, Canada | graxx@xxxxxxxxxxxx http://pages.infinit.net/graxx