Originally Posted by jorgebetancourt
Im willing to try your curves how can i get them.. Can i upload them through arve tools i dont know how to use the other program... Currently I only use the 1000 nit curve maybe i need one that will make things brighter for those movies that are darker.. I've never needed to use the 4000 nit curve..
Do you have a HDR10 calibration disc?
If yes, one option to use with your 1000nit curve, is to play with the master contrast. Dominic has noted adjusting the master contrast does more than we might want, but I have been impressed.
1st calibrate for a contrast level that resolves the highest white clipping value DV LLDV passes thru. For me on the x990, that is the 712/724 or 987/1011 nits white clipping bars. I just start to lose these bars at +12 contrast. This is with both my ChadB normal and bright custom curves. Your 1000 nit curve may result in a lower max contrast value.
Next I set up a level that resolves the white clipping value 660/516 nits bar, for me that is +25 on master contrast.
I believe this to be the range of adjustment I have in order to compensate for how HDR10 titles are handled by the DV LLDV processing.
DV LLDV appears to be remapping all white values above 724/1011 nits, to below that max value. It also appears to be doing so in a way that preserves a white diffuse/peak white relationship we have come to understand and value, in order to offer the appearance of specular highlights. If there was criticism, this is one area where the choices DV LLDV is making, might be different than what we can do on a Lumagen or with MadVR. But as I said earlier, in so far as this highlights relationship is being passed on by virtue of the DV mastering meta data, maybe it is correct.
With regard to the adjustments I am making to master contrast, this is the basis of why I am curious about tweaking a custom curve, so that the master contrast could be left at zero, while working to resolve the white clipping values of the DV LLDV rendered HDR10 test pattern. That way larger portions of the PQ curve would not be altered as they are with the master contrast unless intended.
So, try it with you 1000 nit curve. I think it will be fine, maybe better than the 4000+ nit curves we would traditionally want to use for brighter movies.
Regarding a dark movie... this is where calibrating to 660/516 nit white clipping value can come in handy. Experiment with a title like BR2049, as an example of where resolving white clipping bars below 724/1011 nit resolution, produces good results.