TIFF alpha channel glows on edges When I try to use an image that has an alpha channel, the image has glowing around the parts where there is transparency. Below are images to better explain my issue. Both are using the same image with exactly the same node setup and Cycles render engine.
In Blender 2.90.1 it looks like this:

and in Blender 2.79 it works as expected:

This is the image i'm using. It is a TIF file created in Photoshop

Is this a bug or has something changed in the way alpha is handled?
I haven't used 2.90.1 version for long as I only recently updated from 2.79
EDIT: After packing the TIFF file into the blend file, the glowing disappeared. Then after unpacking the image and adding it to a new image texture node, the  glowing appeared again.
Looks like Blender 2.90.1 treats external and packed files differently.
With image packaged into blend it works for me as expected. The issue appears when TIFF is unpacked and used linked from directory. Troy_s probably will be able to explain the issue, I don't have a knowledge in this area. I can just say how to avoid the issue here.


your TIFF doesn't use Transparency but channel &quot;Alpha&quot; (that is also why option &quot;Save Transparency&quot; is grey when you are saving your TIFF



to avoid the issue copy alpha channel and paste into Mask channel for &quot;Background&quot; layer.



Then when you save with &quot;Layers&quot;, &quot;Save Transparency&quot; is available.



This TIFF is rendered fine in Blender.