32-Bit Image Conversion to 16-bit Tiff

[wlickteig]

I am very new to AP, but I am a long-time PS CS6 user.  I brought a 32-bit EXR image into AP, made a number of adjustments and now I would like to convert it a 16-bit image (as seen on the 8-bit monitor).

I duplicated the layers, then merged the duplicate layers, copied the new merged layer, and finally created a new image from the clipboard, but it destroys the image.  I have tried using tone mapping to correct, but that approach doesn't work. 

I guess I am missing something in the documentation somewhere.

Some assistance would be greatly appreciated.

[Old Bruce]

44 minutes ago, wlickteig said:

I brought a 32-bit EXR image into AP, made a number of adjustments and now I would like to convert it a 16-bit image

At this point I would use the menu File > Save As... then just convert that new document to 16 bit and then flatten, or maybe flatten then convert to 16 bit.

[wlickteig]

When I tried "Save As", it still saves it a .afphoto. 

I do not see a convert option in the menu...

[Old Bruce]

Sorry, it is under Document > Convert Format / ICC Profile...

[wlickteig]

Unfortunately, it brightens (and looses contrast) the image significantly when I convert it to RGB/16.

 

[James Ritson]

Hi @wlickteig, are you using OpenColorIO or have you accessed the 32-bit preview panel (From View>Studio) and set the view to unmanaged (linear light)? If you switch the view to ICC Display Transform you will see what your document looks like with a non-linear gamma transform, which is what will be used when it is converted to 16-bit or 8-bit.

Thankfully there’s a simple way to emulate the linear view: add a live Procedural Texture filter with three channels and do a power transform of 2.2 for each one. Please see this thread for an explanation:

 

Also, there’s no real need to copy to clipboard and paste as new image if all you want to do is export—just add the procedural texture layer at the top then export to TIFF/JPEG etc, all the bit depth and colour profile conversion will be taken care of during export.

There is also a macro that will automate this process in my workflow bundle, it might be useful to you:

Hope that helps!

[wlickteig]

Thank you very much for your assistance!

After going through all the info you provided I now understand the "how" and most importantly, the "why".

[wlickteig]

I may have spoken a bit too early...

The Live Procedural Texture works like a charm on my older Mac laptop (mid-2012 i7), but I recently purchased a mid 2018 i9 running Mojave (and Apple's Metal).

After opening a 32-bit EXR document; making a couple of adjustments with 32-bit Preview; and the adding the Non-Linear to Linear layer; and finally exporting the image is now much darker.

Thoughts?

 

[James Ritson]

Hi again @wlickteig, this sounds like you had OpenColorIO configured on the old MacBook (or you changed the 32-bit view to Unmanaged), whereas on your new MacBook it's likely defaulting to ICC Display Transform, especially if you don't have OpenColorIO configured. In this case, you don't actually need to add the nonlinear to linear layer, just try exporting it without.

The reason I developed the nonlinear to linear macro was for users who were trying to match the transform view from 3D software like blender e.g. when using the Filmic view transform. You can emulate Filmic by using an OCIO adjustment layer and going from Linear to Filmic sRGB, but because you have the added non-linear transform when you convert to 8-bit or 16-bit (this is what ICC Display Transform emulates) you need to add that final correction. If you're using ICC Display Transform and are happy with the results you're seeing on screen, just export without adding the correction.

Easiest way to check what view transform you're using is to go to View>Studio>32-bit Preview and see which option is checked. ICC Display Transform will show you what your image will look like with a non-linear colour profile (e.g. in 8-bit or 16-bit), whereas Unmanaged will use linear light. If configured, you can use an OpenColorIO device/view transform as well.

[wlickteig]

Again, thanks for the info. 

I truly appreciate you taking the time to respond...

[eric_bu]

Hope this help to anyone searching for 32-bit convert to 8-bit:
after loading your image (32-bit) tweak it as you like by adding exposure (and merge), and highlights/shadows (and merge).
When you are on the export panel (JPG), go to "more" and change to RGB 8-bit.
 

Hopes it helps anyone, this was really a pain for me.