Yamaha DPX-1 DLP video projector Calibration
Viewing the test patterns on Video Essentials and the Avia Guide to Home Theater revealed no problem areas. The Yamaha displayed below black on a PLUGE pattern. Colors were crisp and well-saturated, with solid, red-looking reds. Overscan was 5% on top, 4% on the right, and about 2.5% on the left and bottom. DVD resolution was a full 525 lines. The sweep pattern (Video Essentials, chapter 17-2) showed no obvious enhancement. The continuous luminance sweep (18-6) indicated very subtle stair-stepping, though I saw no evidence of this in standard program material. (The most typical symptom is posterization: sharp instead of gradual gradations of shading.)
We were nearly able to verify the Yamaha's contrast specification of 900:1, though only by measuring full-field peak white compared to full black. But the low light levels in a full black field are notoriously difficult to measure properly, and a very small difference there can produce a huge change in the final number. We'll have more to say about contrast in future reviews, but keep in mind that high contrast specs can be produced by displays with mediocre blacks if the peak output is high enough. Contrast measurements taken in isolation are therefore of limited value in rating displays intended for use with full-motion video images.
As delivered, the DPX-1's gray scale was most accurate in the Mid-Low setting. Low dropped the color temperature to around 5500K, Mid raised it to just above 7000K, and the result at the High setting varied considerably, approaching 10,000K in the lower middle part of the brightness range.
Although the factory-programmed Mid-Low gray-scale setting measured respectably (as shown in the accompanying figure) and looked quite good, it resulted in a visible pink shift in the mid-brightness range of the gray scale. Decreasing red contrast by 8% and blue brightness by 1% eliminated this pink cast, but increased the measured color temperature to between 6600K and 6900K.—TJN