Silverfast HDR Studio and Photoshop interaction

[scotttaylor]

I use Silverfast AI Studio 8.5.x to scan 64 bit HDRi/Raw DNG files using a Plustek 8200i scanner. I typically run Silverfast HDR Studio and use it to "review" my scans using the VLT feature. After the scans are created they show up in Silverfast HDR Studio's VLT with "HDRi" and "RAW" tags in the upper right corner of the Thumbnail images in the VLT. At this point I can open any files in HDR studio and use iSRD or any other post processing tools in HDR Studio and the thumbnails will continue to display the "HDRi" and "RAW" tags in the VLT. So far so good... However, occasionally I will open a DNG in Photoshop CC 2015 and "experiment" with the file. So far I have never saved any changes I make in Photoshop back to the DNG file (not even sure if it's possible to save over a DNG?). If I do save changes I've made when working in Photoshop I always "Save As" and use the "Save A Copy" option. So, theoretically I should not be modifying the DNG, correct? Now, if I quit Photoshop and don't save any changes and go back into Silverfast HDR Studio the VLT will display the file I had opened in Photoshop with the changes I made while in Photoshop (Levels, Curves, Shadow/Highlights, etc, etc...). Also, now the VLT thumbnail doesn't display the "HDRi" or "RAW" tags on the file any longer. It seems like Photoshop has saved changes into the DNG and caused Silverfast HDR Studio to interpret it differently. Also, for any DNG files I've opened in Photoshop (and closed without saving) I can't seem to get iSRD to work when I'm back in HDR Studio. Is there something I need to do to "reset" a DNG file so Silverfast will see it as "HDRi"/"RAW" again? Any recommendations on Silverfast HDR Studio & Photoshop workflow interaction would be most appreciated...

[LSI_Ketelhohn]

Dear Scott,

Even though Photoshop will not alter the image content it can alter the metadata.
That can delete data required by SilverFast HDR Studio.
You should make copies of the files for processing in Photoshop.
That would be the safest way.

Kind regards,
Arne Ketelhohn.

[scotttaylor]

Thanks Arne - shame on Adobe for this behavior. Now that I've "corrupted" a number of my "archive" DNG files do you know how I would identify the ones that are corrupt? I've scanned over 2100 slides so going back through them one by one is going to be a PITA...

[scotttaylor]

Forgot to ask... Are there any concerns using Adobe Lightroom to catalog Silverfast generated DNG files?

[LSI_Ketelhohn]

Dear Scott,

Actually I can not answer that because I have not tested it.
If the process does not alter the images, it should be save.

You might want to test this with some images first.

Kind regards,
Arne Ketelhohn.