Okay... scrap the dimmer switch and projector bulb... I get what you are saying now with regard to "fixing" a camera's metering... can't do it if the photocell is worn out and lost its ability to produce liner output. So, if I am able to make a brightness box and my meter output falls outside of desired linearity, replace the bad parts with good ones. I guess we are back to the beginning of this thread, in that going outside and using daylight at different EV's is better then trying to mimic it in a box... without some specialized skills and parts. The old KISS principle. Thanks for helping me out.