hmm, nothing like replying to myself. Anyway, this is an update to the above.
Needless to say that, with further testing, seemed to have discovered a serious issue with the Tools/Replace Metadata feature in Bridge CS6.
On the face of it, attached are two images - one from Bridge CS5 and the other from Bridge CS6. Both feature the contents of the Camera Data tab. While this may mean nothing, it just goes to show that changes have been to the XMP application. Take note that the "Date Time" is missing in CS6. For all their wisdom and experience, Adobe now seems to have found the need to include my camera's serial number instead - very profound indeed.
That's part one. Part two - here's the challenge. In Bridge CS6, choose a folder with some images in it. Select an image. Right click that image and select File Info. In the XMP app, fill in all or any of the fields you deem necessary. To save all this info as template, go to the button between the Preferences and OK button and select Export. This should bring up a dialogue box enabling you to save an .xmp file. OK, this is the way I was doing it in Bridge CS5 and there, it worked fine for me.
OK, next step. In that folder in Bridge, select a bunch of images. On the menu bar, go to Tools. In the drop down menu, select Replace Metadata. Select the template created in the previous step AND, in theory, that should be it. BUT, it isn't. Take a closer look at the dates and times in the batch of images that were selected for the this purpose. In CD6 the date and times gets overwritten and each image in that batch will have or should now have exactly the same date and time. This was never the case in CS5.
As I have understood it, no application - save for EXIF editors - should be writing to or overwriting and of the EXIF data. In looking at all the stuff under the RAW Data tab of the XMP app, all the EXIF and XMP data has been modified on the affected images.
There are several implication here. This most serious is that all the metadata in my images is now screwed up. This in turn affects my sorting criteria, image search and archiving efforts. It also necessitates trashing all the affected images - this because I cannot "rescue" or retrieve the original data. The only way around this is going back to the original or backup image files.
The other implication here is this, it seems that images in CS6 CANNOT now be written to or updated in batches. And yes, I know the difference between Append and Replace. The point is this, how come I had this working in CS5 and where it now seems "broken" in CS6?
Seems to me that this is another example of, "if it ain't broken yet, don't fix it". The question begs, was this a "bug" in CS5 and has since been "fixed" in CS6 and where it is now an "undocumented feature" in CS6?
Would appreciate some feedback on this issue.
