Custom LUT is a new effect that in the past has been provided free through third-party developers. Now it comes with the application, and there’s no excuse not to use LUTs. There are tons of them available online, many for free, that create a huge variety of looks. There are also excellent LUT bundles available for sale from developers like CoreMelt, whose LUTx Color Looks bundle comes with a LUT browser that opens up to show you thumbnails of the available LUTs.
FCPX’s Custom LUT effect is pretty simple and straight forward. You can apply it from the Color category of the Effects Browser, or from the Camera LUT popup in the Settings section of the Info inspector.
In the effect controls you there is a popup that allows you select a LUT from anywhere on your computer, as well as calling up recent selections, and a Reveal in Finder to show you where the LUT is stored.
There are also popups to select the Input and Output to convert between various standards, for instance to convert an HDR PQ or HLG file to standard Rec.709 or Rec. 2020.
This selection can also be made at the bottom of the LUT import sheet.
HDR Tools has similar selection options, also allow conversion from Rec. 2100 PQ to HLG and vice versa. There is also HDR to Rec. 709 conversion.
In 10.3 you could set your rendering output to Rec. 2020 if your library was set to use Wide Gamut color. In 10.4 in addition you can now set rendering out to HDR specifications.
Additionally, there is a Peak Brightness slider that allows you to adjust the brightest part of the image. This is important if you are controlling your video to meet a specific HDR TV brightness.
In addition the scopes can now be set to display in nits for HDR output.
