“The most important aspect of any TV system is the OOTF”

In their Quick Start Guide to DaVinci Resolve Studio, Dolby Vision says to set the input and output DRTs to none on the color management page, which is why we’re guessing that they wouldn’t be overly fond of choosing tone-mapping in Resolve’s OFX CST either – but there’s no prohibition against OOTF that we’re aware of. But what exactly is OOTF and why does it work so well on some of our footage?

Andrew Cotton of BBC Research and one of the developers of HLG, explains how OOTF works:

“The job of the OOTF is actually to ensure that the images seen on the display are subjectively similar to the scene in front of the camera… For scene referred systems like HLG actually you can consider that the OOTF is implemented solely in the display… [whereas with PQ], OOTF is effectively implemented within the camera or the grading suite.” 

“For display-referred systems such as PQ, the OOTF is part of the camera/grading, so burnt-in to signal and cannot vary.”

At ResolveCon 2022, Cullen Kelly also said that for the output transform, Forward OOTF should be checked, so it certainly sounds like it’s kosher to use while grading to us!

Header image courtesy of Andrew Cotton @ BBC