Reply To: About Calibrating HDR-projectors on Calman

[Gregg Loewen]

hello Johnny.

What projector are you calibrating? Some PJs can not do more than rec 709 in HDR (ie: Sony).

In regard to setting the HDR Gamma:
using 2084 (which is an absolute)… I start at considering 1000 nits. If the PJ max output is 150 nits, then take 1000 and divide by 150 = 6.6, so round up to 7. This is the value you will enter in the large Y value for screen offset. So every measurement you perform will be multiplied by 7. Adjusting the Contrast may affect the clipping point, and or roll off.

CalMan also has a BT2390 setting. Where you can select 1000 vs 4000 nits as a starting point. Tyler at CalMan recommends using this method for setting the EOTF on a PJ, Toshi at Sony does NOT recommend this, and suggests my method of creating a screen offset.