Posted on February 27, 2018 By Eric Pfoutz
Vivitek HK2288 Projector Review – Advanced Calibration: CMS Calibration, Calibration Charts
Night Mode Pre-Calibration CIE 1976 Saturation Sweeps (target BT.709)
Night Mode Post-Calibration CIE 1976 Saturation Sweeps (target BT.709)
BT.709 color gamut showed red, magenta and blue over saturated. Using the projectors CMS (color management control) did help reduce their 100% saturation points but the lower in-between levels (i.e 80% 60% 40% 20%) levels are over saturated and could not be corrected with calibration. This issue seems rather common with other recent DLP projectors I have calibrated from Optoma & Benq.
Delta E is a metric for understanding how the human eye perceives color difference. The term delta comes from mathematics, meaning change in a variable or function. The suffix E references the German word Empfindung, which broadly means sensation. Simply put, look at Delta E as a measure of grayscale/color accuracy. 3 and under is considered ‘Excellent’ and imperceptible by the human eye.
Day Mode Pre-Calibration CIE 1976 Saturation Sweeps (target BT.709)
Day Mode Post-Calibration CIE 1976 Saturation Sweeps (target BT.709)
Color gamut seemed to fair better in Day mode. It seems running the lamp in boost mode has a benefit beyond a brighter image by helping improve the color gamut performance. After calibration, nearly all of the mid saturation levels (i.e 80% 60% 40% 20%) are far more accurate.
HDR Mode Pre-Calibration CIE 1976 Saturation Sweeps (target BT.709)
HDR Mode Post-Calibration CIE 1976 Saturation Sweeps (target BT.709)
Note: These are the default values of my projector when viewing HDR (user mode). Yours may be a little different. I recommenced you leave yours at their default value.
While in HDR mode all of the colors in CMS were pre-calibrated from the factory, along with color set to 75 & tint set to 47, which I found a little odd. Measuring/calibrating BT.709 color gamut while in HDR mode was very difficult to do. I used an HDR workflow that allows me to measure a BT.709 color gamut within a BT.2020 container. Problem was no matter what options I tried with my calibration software some of the colors, especially magenta measured and looked way off. However, the colors in my SMPTE color bars test pattern looked good as did real-world content from my UHD blu-rays. So, I decided it was best to leave all 6 colors in CMS and color/tint alone.
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