Using OpenColorIO

Setting up OpenColorIO

By default, Photo's OpenColorIO features are not immediately usable. An .ocio configuration file is required alongside a number of supporting files such as lookup tables.

The OpenColorIO website (http://www.opencolorio.org) contains some sample configurations that provide a number of suitable input and output profiles, including several Academy Colour (ACES) configurations.

To configure OpenColorIO in Designer:

1. From your iPad (iPadOS 15 or later), download your preferred configuration files. Importantly, for iCloud users, move the files out of iCloud's Downloads folder to On My iPad (the Affinity Photo subfolder is a good location) or other iCloud folder.
2. Uncompress the .zip or .tar.gz files in this location.
3. Using the iPad's Files app, convert your chosen contained OCIO folder to a package by long-pressing and choosing Rename, then add an ".ocio" file extension. For example, a sample configuration with the new extension might be "aces_1.0.3.ocio". You may see this temporarily display with a double extension, e.g. aces_1.0.3.ocio.ocio, which is acceptable.
4. Within Affinity Photo, access the Preferences from the welcome screen and navigate to Colour.
5. Select Choose OCIO Package, then navigate to the .ocio file that you renamed previously and select it.
6. OpenColorIO will now be configured. Open any 32-bit document to see additional viewing options.

Using OpenColorIO

OpenColorIO is exposed in Affinity Photo through two methods:

• The View Tool will contain additional preview options that only become available with a valid OpenColorIO configuration. These can be used to achieve a non-destructive, colour managed workflow.
• An OCIO adjustment layer (see OCIO Adjustment) can be added to losslessly convert between colour spaces. You can have multiple OCIO adjustment layers within a document, which allows you to accommodate composite layers from different colour spaces. An example layer stack might be (in hierarchical order):
  • OCIO Adjustment—from Utility - Linear - sRGB back to Role - scene_linear
  • sRGB Pixel Layer—composite element
  • OCIO Adjustment—from Role - scene_linear to Utility - Linear - sRGB
  • Pixel Layer—original layer