Posted on July 16, 2018 By Eric Pfoutz
BenQ TK800 4K UHD Home Entertainment Projector Review – Advanced Calibration: CMS Calibration, Calibration Charts
BenQ TK800 Cinema Mode (user 1) Pre-Calibration CIE 1976 Saturation Sweeps (target REC.709)
BenQ TK800 Cinema Mode (user 1) Post-Calibration CIE 1976 Saturation Sweeps (target REC.709)
The default CMS looked to be hand adjusted at the factory because the values for all six colors were not at their centered (default) positions. Pre-calibration primary colors weren’t too bad. Red was under saturated across the entire range, blue and green were over saturated a little. The 3 secondary colors especially cyan and magenta suffered from major hue errors with both colors positioned too close to blue. Cyan in particular had a wicked problem with 100% saturation jumping to the green side. This error could not be fixed only massaged to a better compromise. The most post-calibration improvements actually resulted from my white balance calibration. Actual CMS work made for only small changes.
BenQ TK800 Bright Mode Pre-Calibration CIE 1976 Saturation Sweeps (target REC.709)
BenQ TK800 Bright Mode Post-Calibration CIE 1976 Saturation Sweeps (target REC.709)
Bright mode color gamut was similar to Cinema mode mainly due to both modes running Brilliant color on. Cyan tracked a little better this time but still had that weird plus-green error at 100% saturation. Yellow was worse, erroring towards green. The 3 primary colors (red, green & blue) were about the same and magenta had a similar plus-blue error just less server. Now just like with Cinema mode a lot of these errors were improved by white balance calibration with CMS fixing smaller errors especially with color luminance.
BenQ TK800 User 2 Mode Pre-Calibration CIE 1976 Saturation Sweeps (target REC.709)
BenQ TK800 User 2 Mode Post-Calibration CIE 1976 Saturation Sweeps (target REC.709)
BenQ advertises the TK800 as reproducing the 92% of the REC.709 color gamut. So, it is presumed when watching 4K/HDR the incoming P3 color gamut is down converted to REC.709. What I found odd however that there is a Color Gamut adjustment in the user menu with REC.2020, DCI-P3, REC.709 and Auto selections. So why would they include REC.2020 & DCI-P3 if the projector only does 92% of REC.709? Why have a REC.2020 selection when there are no displays (projector or flat panel) that can even come close to REC.2020. Most 4k/HDR displays fail to reach a 100% of the DCI-P3 color gamut with all 6 colors.
Leaving the color gamut set to Auto seems the best choice as it’s the same as if you had selected REC.709. I measured both REC.2020 & DCI-P3 and neither were very good. They were similar in their poor performance. Red mid saturation points were way over saturated with 80% near the same as 100%, same with cyan. Yellow was too red and magenta was skewed toward red at 80 & 100% saturation. Blue was the only color that was correct.
With color gamut set to Auto the TK800 showed similar issues as my 1080p/SDR calibrations and improvements were made in the same manner with white balance calibration making the biggest improvement and with CMS fixing smaller errors especially with color luminance.
© 2019 Projector Reviews (V0625)