When calibrating projectors, you put the meter in the beam path and adjust contrast, brightness, primary and secondary colors to set grey scale. You can do this anywhere and it is well worth $100. You can then find out what additional tweaks are needed for screen offset, which you can do yourself. I calibrated mine with the meter in the light path and did not feel the need to re-do with screen offset and I’m using a grey screen. When you get the projector, you will want to throw up a test pattern with pluge bar and adjust contrast / brightness to your liking. After 500 hours, do it again to compensate for initial buld burn in. You should not need to get back into the RBG adjustment after the initial calibration.
