When using Lightroom, I edit a photo in Topaz Adjust. When the edited photo is imported back into Lightroom, some of the metadata is missing - namely the focal length, ISO, shutter speed, and aperture. I notice these things because they leave a big gap in the Loupe info, which makes me think that other data may also have gone missing.
Is there a way I can use Lightroom to restore this data to the edited image?
If you're using Fusion to get to Adjust, you should be returning a copy of the image to Lightroom, so the original image should still be available in the stack to copy and paste the metadata from. Fusion is a very basic plugin host/editor, and while it's a workaround for Lightroom, it's actually intended for people who don't have any sort of an image editor installed (point-and-shoot types).
Note that Topaz is releasing a new product (should be this week or next), photoFXlab, that is more Lightroom-friendly. The release price is $29; the retail price after release will be higher ($79, IIRC). I've only seen the sneak peek, but it's supposed to act like a LR plug-in from Lightroom rather than as an "edit in" option, and provides a layering/masking environment while the image is in the plugin. It will still work as a stand-alone, as Fusion does, but as far as I've been able to determine it's supposed to work directly from LR as well.
ADDED: After a glitch in the 1.0 version forced a hold (a new product registration system left some users unable to use the software), photoFXlab 1.1 has been released (today — June 29, 2012) with the old product key registration system, the "social" features removed, some genuine UI improvements, and I can confirm that it maintains metadata when round-tripping from Lightroom. The $29 launch price has been extended to July 31, 2012. (I must really be starting to sound like a shill, but I've been bugging the good folks at Topaz about this for a while, and I'm kind of impressed with the improvements they made while fixing the registration system. It feels like more than a dot release compared to 1.0.)
One way around would be to backup metadata using exiftool and then recover them after processing. The backup can be made to XMP or to more elaborate MIE format.
There are also GUI tools for metadata backup.
I think the answer is "yes" and Syncomatic might be the tool to do it.
