Roundtripping Clips Between Colour Spaces

In Batch, Batch FX, and the Modular Keyer, you can use the Shift+T+click combination to copy Colour Transform settings from one node to another while toggling the Invert option. For example, this makes it easy to convert content from input colour spaces such as ARRI LogC to a single working space such as linear Rec. 709 or ACEScg, and convert back to ARRI LogC for grading and finishing. Or alternatively, to convert from your usual working space to a different one to perform a specific operation and then convert back again.

This feature is supported for the Input Transform, View Transform, and Colour Transform modes (including Custom mode in Colour Transform). Any custom OCIO Context Variables on the node are also copied.

1. Set the Colour Management attributes in any node that supports them (i.e., Clip node, Colour Mgmt node, Render node, Write File node, etc.).
2. If you haven't already done so, add another node that supports the Colour Management attributes.
3. Make sure that the destination node is selected.
4. Press Shift+T and click on the node that you want to copy Colour Management attributes from.

General Information About Colour Transform Inversion

Some colour transforms are impossible to invert perfectly. This happens when they map multiple input colours to the same output colour, such as when transforming from a large space to a smaller space. In these situations, the Invert option maps the original output colour back to one of the original input colours, but applying the forward transform followed by the inverse transform will inevitably change some colours.

To check that the inverse is as accurate as possible, compare the result of applying just the forward transform to the result of applying the forward transform, followed by the inverse transform, followed by the forward transform again. If they match, then the inverse is accurate within the range of colours that may be inverted.