Thanks again Bill. I agree with what you wrote above. I might perform one more test before deciding on what process control test I will regularly perform. That test I'll do is to repeat my testing of photographing a transmission step tablet under particular controlled conditions. That is to stick the tablet onto a piece of white translucent perspex, masking off all areas outside the tablet as seen by the camera then affixing that assembly to an outside facing window, and finally draping a black cloth between the mask and the camera to ensure no additional light can enter. This is about as controlled as I can get the conditions when including the camera in the testing process.
Originally Posted by Bill Burk