Optoma GT720 Projector - Performance

Posted on July 14, 2011 by Art Feierman

In this section we consider the brightness, sharpness, and image noise of the Optoma GT720 home theater projector. Also considered are the physical attributes of light leakage and audible noise of the GT720.

Optoma GT720 Brightness

Lumen Output and Color Temp at 100 IRE:
Cinema	1143 @ 6721 (with default BC of 6)
Bright	2121 @ 6807
Presentation	1535 @ 7811
Classroom	1315 @ 6771
Blackboard	1969 @ 6692
Game	1640 @ 7643

Lumen Output, Low Lamp, Bright mode:

GT720 Projector measures: 1941 lumens

That represents a drop of only about 8.5%. Most projectors drop 20-30% in their eco-modes. It would seem the wise thing for most owners to run in eco-mode. That's a small drop in exchange for longer lamp life, and Optoma says the GT720 will get 3000 hours at full power, but 5000 in eco.

Brilliant Color plays a big role in the GT720. With Brilliant Color off, in fact, you have less than 1/3 the brightness of setting it to 10. As Optoma has even Cinema defaulting to 6, I figure they don't expect you to use settings lower than that.

Effect of Brilliant Color on lumen output (Bright mode):
BC on 10 (default)	2121
BC on 6 (as in Cinema)	1442
BC on 0	631

Color Temp over IRE Range:
	Cinema
30 IRE	6221
50 IRE	6254
80 IRE	6648
100 IRE	6721

After Mike's full calibration, placed in User (has to be there), with Brilliant Color set to 10, the Optoma GT720 measures a rather dazzling 1810 lumens (and a color temp of 6321K at full white). Below are the calibrated color temp results, a significant improvement over the default Cinema or User 3 above:

Color Temp over IRE Range (Post calibration):
20 IRE	6603
30 IRE	6630
40 IRE	6642
50 IRE	6589
60 IRE	6828
70 IRE	6626
80 IRE	6426
90 IRE	6407
100 IRE	6321

Note that after Mike's calibration, the brighter ranges got a bit warmer (lower color temps), the opposite of pre calibration. But, the amount of shift is a lot less. Still, the GT720 does end up with slightly pushed reds. For a gaming projector - no problem. For serious home theater, most others can do a little beter.