Hi steve
In the attachment location, what is the difference between
soft roll off and BT2390 tone mapping? And in what situations should I use which one?
I read the description of BT2390, and it seems to be a kind of roll off, and it is different from the algorithm of st2094-10/20/30/40
What is the file definition of the soft roll off algorithm?
Thank you very much

As per the Guides:

"Within Soft Roll Off the Target upper start % options defines the level at which highlight roll-off starts, while Target lower start % defines the level at which shadow roll-off starts.
BT.2390 Tone Mapping has roll-off defined by the Mapping option presets drop-down."

Not a lot more that can be said really.
Which to use is up to the user, based on the final image.

Steve

Steve
So the difference is that Soft Roll Off can manually set the starting point of highlight/shadow roll-off, while ST2390 cannot be set manually and is fixed by the algorithm?
In addition, may I ask the Soft Roll Off algorithm is defined by which standard file?

BT2390 is defined within its standards specification.
Roll-off is just roll-off, adjustable as the User Guide defines.

Steve

FYI, that mapping technique has been removed from the current in-force revision BT.2390-11, and instead appears in BT.2408-7 Annex 5.

argonaut
Thanks, I only read the latest bt2390-11 before, I didn't find this part, I saw colourspace and realized that it was hidden in 2390-3, so it ran to bt2408-7!
In addition, bt2408-7 proposes a new color coding method maxRGB, which can simultaneously prevent color space overflow and also keep hue unchanged, just can't let saturation vary naturally with brightness. But there isn't a perfect solution for all five, I wonder if steve would consider adding it