[jwhite]

Right. I think the point is that in our test environments, when we mount the high target high, it would inevitably be directly in line with a fluorescent bulb. This gives the camera's white balance code fits In fact, in one space we used, we also had shifting daylight affecting the white balance. We spent hours fiddling with the settings, particularly the white balance settings. Our initial mistake was to focus entirely on trying to make the image green. In some cases, that was impossible. Realizing that we could choose the setting that gave us the best image, and adjust the threshold constructor to match was a break through for us.