2017

■ Assuming that the content was graded and approved on a projector with a typical P3 gamut, limiting
the colors to that gamut assures there will be no unpleasant surprises if the content is later viewed on a
device with a wider gamut.
To achieve this:
1 Select the RRT+ODT for the device whose gamut you want to limit to, for example,
RRT+ODT/ACES_to_P3-D60.
2 Then add transforms to convert to DCI/SMPTE X'Y'Z', for example, display/projector/P3-D60_to_CIE-XYZ
followed by display/DCDM/CIE-XYZ_to_DCI-D60.
Color Managing Images from Scanned Film
Images from scanned film are typically supplied as DPX files with Cineon-style log encodings. However, the
Cineon encoding was never fully standardized, and various vendors use slightly different implementations.
Academy Density Exchange (ADX) is a standard developed by AMPAS to eliminate any confusion and
standardize on a single implementation. ADX is part of the ACES system, and is included in the SMPTE 2065
set of documents.
There are a couple of transforms for importing ADX-encoded images as scene-linear values. If you are
importing DPX files from a properly calibrated ADX scanner, use one of these transforms:
■ film/ADX/ADX10_to_ACES.ctf for 10-bit integer files
■ film/ADX/ADX16_to_ACES.ctf for 16-bit integer files
If the images did not come from an ADX scanner, try importing them with one of the ADX transforms
anyway as a first resort. If you are not satisfied with the result, you can try one of the Log_to_Lin transforms
in the film/LogLin/ directory. However, be aware that these transforms modify each color channel
independently (similar to 1D LUTs), and do not attempt to account for the channel cross-talk in film like
the ADX_to_ACES transforms do.
Alternatively, you can try using one of the print-film emulation LUTs in the Lustre Color collection, if they
are available to you. These transforms are installed with the Autodesk Creative Finishing products, as well
as with Autodesk Composite. The transforms are supplied in the legacy .3dl format, and can be imported
by Autodesk Color Management. Refer to the
Lustre Color Management User Guide for more information about
the transforms in that collection.
NOTE DPX files may contain values other than Cineon-style log-encoded colors. For example, they may contain
video colors. When working with DPX files in general, you need to know the specific color encoding used. There
may be metadata available in the files, but even when metadata is present it can be incorrect or misleading.
Color Managing Digital Cinema Camera Footage
The camera/ directory contains transforms for importing and converting footage from various digital cinema
cameras to ACES. Use the transform that matches the specific camera model and lighting conditions (e.g.
daylight or tungsten), as appropriate.
The input transforms that specify the illuminant are not designed to perform white balancing — for example,
using a transform for tungsten illumination will not turn whites blue-ish. Instead, the different transforms
take into account the different spectral power distributions of the different illuminants.
Once the footage has been converted to ACES, you can use the other transforms in the collection to convert
it to your working space, if necessary.
1314 | Chapter 25 Colour Management