In DELTAGEN 2018 and before, the generation for greyscale passes like e.g. Ambient occlusion shadow baking or Depth differed slightly in Look and Stellar.
The Look renderer always wrote the generated output to all three color channels of the chosen output image format, while Stellar uses only one channel.
This has changed for DELTAGEN 2018x to align the behavior for both render modes:
Look now also writes the greyscale output to only one channel. However the user can change the output back to a 3 channel grayscale image with choosing a “3x…” format from the drop down menu in the passes tab of the Render export.