2017

The cursor changes to a colour picker.
2 Click the image.
Both source and result colours are sampled simultaneously. The RGB values for the selected pixel are
displayed, and the sampling boxes take on the corresponding colour.
Roundtripping Clips Between Colour Spaces
In ConnectFX, 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 ARRI LogC and other colour spaces to a single working space such as linear
Rec. 709 or ACES, and convert back to ARRI LogC for grading and finishing, or to convert from your usual
working space to a different one to perform a specific operation and then convert back again.
1 Set the Colour Management attributes in any node that supports them (i.e., Clip node, LUT Editor,
etc.).
■ Make sure that a colour transform or a custom chain of colour transforms is selected.
■ Make sure that Custom is enabled.
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.
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. It is
analogous to the fact that you cannot convert from a 12-bit signal to 8 bits and back to 12 bits again without
data loss. 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 colors that may be inverted.
Exporting LUTs and Colour Transforms
Exporting a LUT or colour transform from the
LUT Editor (page 1277) is different from saving a setup:
■ PhotoMap, EXR Display, Gamma, Lin to Log, and Log to Lin are exported as baked 1D LUTs (.lut files).
When imported, you can modify their curves only with the Advanced settings.
■ A chain of colour transforms is exported as a single .ctf file that losslessly preserves each component
operation. When imported, you cannot modify it.
Exporting a LUT
1 Access the LUT Editor.
2 Click Export.
The file browser appears.
3 Type a file name for the LUT in the Export field.
4 If you want to generate an inverse LUT with the _inv suffix appended to the file name, make sure that
the Generate Inverse Lut option is active.
5 Click Export.
Applying Colour Management to Clips | 1293