ID 401616 - Using a custom OCIO configuration and projecting an image via Projectors displays darker results compared to the paint through tool

Problem summary
Projecting an image via Projectors displays a darker result compared to utilising the paint through tool, while using a custom OCIO configuration.  

Customer reported version

mari.4.5v2

Customer reported platform

Steps to reproduce

1) Launch Mari 4.5v2 and load the example head project. 

2) Go to File->Settings. Select 'Custom' as 'OCIO Config' and load the custom OCIO file in 'Custom OCIO Config'

3) Open Projectors and create a new one

4) Under 'Unprojection' set the 'Color Depth' to the appropriate bit depth of your imported image, for example 16 bits

5) Under 'Actions' click on Import and select the image you want to use, for example ACEScg_ColorChecker2005.exr. This will project automatically on the example head. 

6) Open the Image Manager and import the same image

7) Drag the imported image from the Image Manager onto the example head. Resize the image in the viewport to focus on colours that are already projected onto the model from the Projectors step. Paint a section to use as comparison. 

Result: The image projection via Projectors appear darker (entire head preview) compared to the Image Manager paint through tool result (central painted section):
 

Expected behaviour

Projecting an image using Projectors or paint through tool should give the same results. 

Actual behaviour
Projecting an image using Projectors results in darker colours compared to using the paint through tool. 

Workaround
Unknown. 

Reproduced by support

This bug has been reproduced in:
Mari 4.5v2 on Windows 7 and Linux Centos 7
Mari 3.4v4 on Windows 7 and Linux Centos 7

Earliest version tested

Mari 3.4v4