Front Projectors

The top chart shows the HT300 XTRA's gray scale relative to its color temperature at various levels of intensity, or brightness (20 IRE is dark gray; 100 IRE is bright white). The gray scale as set by the factory, in the low color-temperature mode and the film gamma mode, measures extremely blue with the darkest images and fairly blue across the rest of the gray scale. After making adjustments using the Photo Research PR-650, the gray scale measures well, within 315 kelvin of D6500, the accurate color temperature, across the entire range. This is an improvement compared with the performance before calibration. After calibration, the 20-IRE window was too dark to measure with our PR-650, but it was visibly more blue than the next-higher IRE, indicating a similar jump in color temperature that is apparent in the before measurements. The bottom chart shows the gray scale (or color temperature) relative to the color points of the display's red, green, and blue color-filter-wheel segments. Red (x=0.356, y=0.326), green (x=0.295, y=0.612), and blue (x=0.147, y=0.084) are close to those specified by SMPTE. Red is slightly oversaturated, as is green, only less so. The light output was approximately 15 foot-lamberts on a 6-foot-wide Stewart Studiotek 130 (1.3-gain) screen. The projector has excellent DC restoration and an accurate color decoder. The HT300 XTRA displays approximately 480 lines (per picture height) with NTSC sources and, using our Leader LT-446 HD generator, is capable of resolving 720p and 1080i signals out to the limits of its 1,280-by-720 chip.—GM