Clamp Colors in Photoshop 32 bit float Color Depth

Photoshop CC 2018

Photoshop CC 32 bit float linear workflow is developing nicely but it still lack some needed basic components, and one of them is a Clamp Color Adjustment, equivalent to a node you will find in any 32 bit float HDR capable compositing software.

Clamping the colors means limiting the britest values to set values, usually 1.0 – white and 0.0 – black, so that no pixels will have higher than white or lower than black (negative) values that can create unwanted results in further operations.

* Brighter than white (super-whites) and negative colors are a feature, and part of linear 32 bit float color processing.

* If there is such an option that I didn’t find please let me know..

In order to clamp the layers colors we convert it to a Smart Object, and convert its color depth to 16Bit internally, so the individual layer gets clamped but the main document remains 32Bit float unclamped (HDR).

To clamp the colors of a layer:

  1. Convert the layer or layers to a Smart Object.
  2. Enter the Smart Object for editing.
  3. From the Image > Mode  menu, choose 16Bits/Channel,
    And in the Conversion dialog that opens choose ‘Don’t Merge’, or choose Merge and then in the HDR Toning dialog choose Exposure And Gamma mode to keep the image unchanged.
    The conversion to 16Bit color depth without Merging or Merging using default Exposure and Gamma mode will clamp the colors.
  4. Save the Smart Object.
  5. Return to the main document, the layers colors are now clamped.


Adobe Bridge Warning

Adobe Bridge CC 2017

Adobe Bridge is very useful for browsing media in a CG \ Animation workflow,
mainly because it displays thumbnails and previews for EXR files, something that Windows Explorer doesn’t do, and also because it has cool batch functions like loading files as layers in a new Photoshop document and so on,
But I encountered a behavior that can be problematic,
The software uses caching for the thumbs and filmstrip preview in order to display the images faster,
And in some cases where you render updated files with the same folder structure and same names, Bridge will display the older preview images from it’s cache even if you manually deleted the whole folder structure prior to re-rendering!!
I stumbled across this issue when browsing render tests being confused as to why Blender rendered images with old settings, I naturally thought Blender was to blame (I tend to think that a media viewer can’t be the problem because it just displays images..) and looked through the render setting trying to understand what went wrong,
Eventually I found the cause of the problem in Bridge,
And there’s a simple solution with the command:
Tools > Purge > Purge cache for _______ folder
But you still have to be mindful that you might be seeing old renders, otherwise you won’t perform this important action.