In doing research for my article 32-bit HDR Myths and Methods, I came across a strange occurrence. A 32-bit Floating point Tiff HDR file I processed in Photoshop CC (Not ACR), saved as a new 32-bit Tiff file and then imported into Lightroom looked absolutely Horrid.
Here, I’ll show you. The Photoshop Image is on the Left (as viewed in Lightroom) Click for large view
Both images are from the same 32-bit tiff and both processed the same way, One in Lightroom, One in Photoshop CC (using The Camera RAW Filter as a smart Filter) Both images when processed looked the same in their respective Software.
But when I imported the Photoshop file into Lightr0om, the Photoshop image looked garish, over saturated, over everything.
At first I passed it off as just the difference between how Lightroom/ACR renders previews and how Photoshop does. The process is a little different and results in images looking slightly different depending on where you viewed it. But this was far more than that. It was unusable.
So, then I noticed on the Photoshop Image when viewed in the LR Develop Module that the develop settings were the same on this different file name as they were on the Lightroom edited file. How could this be? The LR edit does not carry over to Photoshop. (in 32-bit)
Then I figured out what was happening. When the Original 32-bit Tiff was made using HDRsoft Merge to 32-bit. I have Lightroom set to also write Develop data to a side car XMP File. That XMP file gets up dated in Real Time. So I edited the image in Lightroom, those changes were written to the XMP. I then outside of Lightroom directly opened the 32-bit Tiff in Photoshop. Photoshop since it is Pixel editing not Instructional editing, can not read or do anything with the XMP info so the image appears un-edited in Photoshop, which is fine, I want to edited them differently and save as a new file name when done.
I do the edits and then save the with a new name.
Now when I import that image into Lightroom. Lightroom now sees the new image AND a copy of the original XMP file which now has been updated with Edit info and it now applies that to The Photoshop file. Thus double processing the image.
Once I knew that, the fix was very easy. Simply take that image into the Develop Module and click “reset”. Fixed
*Edit and follow-up 4/19/2014*
In testing today a slightly different method I was able to avoid the Double Processing problem. Instead of simply using the Open Dialog in Photoshop on the image, I instead just used the Edit In command in Lightroom and then “Edit Original” which would open the 32 Bit Tiff but without Lightroom Adjustments. But even with doing this method and not having double processing image. Upon re-importing the Photoshop image into Lightroom, there STILL is the problem of how differntly Lightroom/ACR Renders 32 Bit Images as how Photoshop does. The difference (which I believe to be Gamma related) is really pronounced… take a look