Resolve 1000 nits clipping possible?

Discussions - Using ACES Post (DI, Edit, Mastering)
1

Hello,

I use aces cct with resolve for HDR grading (P3D65-1000 nits odt). It happens that the signal exceed 1000 nits in some channels (just a bit, 1019 nits in our case). Is It possible to have a simple hard clip limiter in a dctl ?

Thanks

2

It is possible to use a custom DCTL Output Transform in Resolve 17. But the real question is how you are hitting 1019 nits. The 1000 nit Output Transforms already effectively have a hard clip built in. And in fact, due to the order of operations of the chromatic adaptation, you end up with one channel slightly low. It should not be possible to get a value over 1000 nits (10-bit code value 769).

This screen grab is an ACEScct white solid, graded to the maximum output (P3-D65 ST.2084 1000 nits Output Transform):

pq_max
pq_max1039×592 72.9 KB

10-bit code value 765 is actually 964 nits.

3

Hi Nick,

yes I thought there was clipping too. Here are screenshots.For the blue example, I have forced to get the issue but the second example, this is a real grade. On this screenshot, the picker moved, but I have 0771. This is the frame I have an cll > 1000 nits in transkoder and resolve analysis.

Thanks
example
example2