- Written by Chris Eberle and Ross Jones
- Published on 22 February 2010
- Optoma HD20 Single-chip 1080p DLP Projector
- Page 2: Design of the Optoma HD20 DLP Projector
- Page 3: Setup of the Optoma HD20 DLP Projector
- Page 4: The Optoma HD20 DLP Projector In Use
- Page 5: The Optoma HD20 DLP Projector On the Bench
- Page 6: Conclusions About the Optoma HD20 DLP Projector
- All Pages
On the Bench (Chris Eberle)
Optoma HD20 Benchmarks
Equipment used: EyeOne Pro spectrophotometer, CalMAN Professional 3.3 analysis software, Accupel HDG-3000 signal generator, Spears & Munsil Benchmark Blu-ray.
All measurements were taken off the screen (Carada Brilliant White, gain 1.4) from the seating position (10 feet).
After performing a factory reset I engaged the User mode for all measurements. This gave the best out-of-the-box results for color and grayscale. Here is the color gamut and luminance chart. This is decent performance with a very watchable image. The main issue is the color luminances are too high resulting in a slightly over-blown look.
Grayscale ran somewhat cool on the default Warm setting averaging around 7200 Kelvin. Gamma was also quite low with a 1.76 average.
After calibration color was much improved by reducing the color ten clicks (10 percent) and the tint by one click. Secondaries were positively affected by the grayscale calibration and lined up quite well when calculated from the measured primaries.
Calibrated grayscale tracked very well after adjustments to the gain and bias controls. The adjustment steps are quite coarse but I was able to achieve very flat tracking despite this. Gamma also measured well after changes were made to the Film gamma preset.
One note about the gamma chart above: Though the gamma tracking measures flat and just under the target of 2.2, I observed very obvious instabilities in the actual black levels. I adjusted brightness using a series of Pluge patterns with bars that are 4% above black and 4% below black. The patterns rise in average picture level (APL) from zero to 50%. As the APL increased, the black levels decreased. When going from a zero APL pattern to a 25% one, the +4% bar disappeared. This made setting the brightness extremely difficult. The best I could do to preserve some low-level detail was compromise so I could still barely see the +4% bar at 50% APL. This made the darkest content gray rather than black but it was the only way to preserve any shadow detail.
Dynamic range wasn’t too bad with a minimum black level of .004. I adjusted the contrast to a peak white level of 13.44 foot-Lamberts for an on/off contrast ratio of 3360:1. The loss of shadow detail in brighter scenes was noticeable however. I have watched the Spears & Munsil montage hundreds of times so I am very familiar with the content. In the sunflower clip near the beginning I could not see the seeds in the flowers as I normally do. The detail in the brown machinery was also crushed. Near the end when the cityscape fades to night, blacks turned to gray as the scene darkened.
Optical performance was good with solid focus in all areas of the screen. Detail in the Spear & Munsil montage was well-rendered. I observed a slight shift to red on the left side of the screen and slight shift to green on the right. As there is only one imaging chip; and therefore no convergence error; this is a lens issue. Video processing was also good with all source adaptive tests passed except 2:2 pulldown. Edge adaptive tests looked excellent with superb handling of the jaggies in all scenes. 1080p/24 was processed correctly and there were no pixels cropped in the 16:9 mode.