Test Bench: Optoma HD81 1080p DLP Front Projector
Color temperature (Warm color temperature before/User color temperature after calibration): 20 IRE: 7,071/6,322 K 30 IRE: 6,557/6,167 K 40 IRE: 7,207/6,476 K 50 IRE: 7,452/6,579 K 60 IRE: 7,659/6,688 K 70 IRE: 7,562/6,539 K 80 IRE: 7,567/6,644 K 90 IRE: 7,511/6,431 K 100 IRE: 7,186/6,314 K Brightness (100-IRE window before/after calibration): 16.5/15.6 ftL
The Optoma HD81's warm color temperature preset measured fairly close to the 6,500° kelvin grayscale standard, although green levels were somewhat deficient from 40 to 100 IRE at that setting. Adjustments to the red, green, and blue brightness and contrast settings in the User color temperature submenu helped to deliver more accurate performance. Afterward, grayscale tracking measured ±200 K from 40 to 90 IRE - a good showing - with only a small dip toward blue at the high and low ends. (Calibration needs to be performed by a qualified technician, so discuss it with your dealer before purchase or go to imagingscience.com to check for a technician in your area.)
The Optoma showed a slight amount of color decoder error (-5% green) via both its HDMI and component-video inputs. Color points were very accurate - a factor that, along with the projector's precise color decoding, contributed to its rich, well-saturated color on all kinds of source material.
Overscan - the amount of picture area cut off around the edges - measured 0% for both the HDMI and component-video inputs with 1080p test signals and either the 16:9 or Native display mode active. The projector's variable Overscan feature lets you vary this amount, however. Both 1080p and 720p test patterns revealed full picture resolution for all high-def inputs.
The HD81's post-adjustment maximum picture brightness as measured from a 100-IRE window on a 93-inch-wide screen was 15.6 foot-lamberts - nearly the same as for the more expensive Sim2 HT-3000 tested in the October 2006 Sound & Vision. And using the projector's manual iris feature, we could improve its already impressive picture contrast even further.