Projector Reviews - General Performance-7

Posted on October 14, 2006 by Art Feierman

Optoma HD70 Projector Calibration

First of all, out of the box color was very good to start. The color temperature in Cinema mode was a little warm (reddish), with full white measuring 6408K, very close to the ideal 6500K. As I measured grays, the color temperature dropped with the lower brightness gray, with


80IRE	6214K
50IRE	6204K
30IRE	5979K

The default color temperature setting is 1. I had better luck, (slightly cooler temperatures) with the setting at 2. The numbers are impressive


100IRE	6633K
80IRE	6323K
50IRE	6391K
30IRE	6158K

After calibration, the numbers got about as good as anyone could hope for:


100IRE	6575
80IRE	6544
50IRE	6489
30IRE	6335

To get those numbers the projector was still in Cinema mode, low power, defaults for BrilliantColor and TrueVivid. The individual RGB settings were:
Gain:
Red 6, Green 5, Blue 6
Bias:
Red -14, Green -12, Blue -13

(Those are the settings that yielded the 363 lumens.)

The primary change I made in the Bright mode adjustment that yielded the 1424 lumens mentioned above, was increasing the Blue Gain to 13. This because in Bright mode the color temperature was still down in the 6500K and below range, whereas for HDTV and bright viewing color temperatures up to about 8000K provide good results. (Note, the Mitsubishi too, was down in the 6800K range, also rather warm for HDTV and sports viewing.

Image Noise

The Optoma HD70 did very well here. I ran the HQV disk on it, and it looked very good on the noise tests. The same was true for movie watching. Sure, if you get close enough to the screen you can see noise easily (as with almost any projector), but at normal seating distances when some is visible (on the right type of content, it is very minor and not distracting. No problem here!