Epson Home Cinema 3700 Calibration Presets notes
I preformed 2 calibrations on the 3700, one for a dark room using Cinema mode (medium lamp) and a brighter day mode using Bright Cinema (bright lamp). Overall calibration went as expected, except there was one issue I observed with the color red when calibrating it using the projectors CMS controls. We normally calibrate the 6 colors using 100% saturation test patterns and try to put the colors at their correct (REC 709) x y coordinates and at their proper 100% luminance levels.
If you look at either the before or after CIE charts you will see 100% red (outer dot) is a little under saturated and pushing towards yellow/green, while 80, 60, 40 & 20% are all over saturated and pulling towards magenta/blue. As I tried to move 100% red to its x y (box) it caused 80, 60, 40 & 20% to all move even further towards magenta/blue turning red more to pink. So, 100% red was slightly orange and 80 and below was pinkish. Now most of the content we watch is not at 100% levels so I only made a small adjustment to red, otherwise skin tones would become too pink. I hoping this issue is only with this 3700 sample.
I was able to achieve outstanding white balance and near perfect 2.40 gamma curve in Cinema mode. Bright Cinema is designed of course to be bright and one way they achieve this is to have a very bright gamma curve, 1.56 in this case. As I tried to lower the gamma to my target of 2.10 it lowered the peak white down too much, similar to what we got out of Cinema Mode thus losing any benefit of a brighter mode. So, I only lowered the gamma to 1.87 to keep the overall light output up.