Rob Cole has a plug-in called Preview Exporter that will enable you to do what you need. Rob is a regular contributor here, and very knowledgeable. I have not used this plug-in, but he highly recommends it. You will have to scroll down quite far to find it.
You can recover the previews ... and they would be smaller size (fewer pixels) than your originals ... but your 72dpi comment is incorrect ... using this plug-in: robcole.com - PreviewExporter
But I don't understand something ... don't you have backups of everything? Isn't that what RAID is for? Did you accidentally wipe out both RAID drives?
Professor Royal wrote:
I purchased DATA Rescue 4 and was able to retrieve most or all of the jpg and Cr2 files but what I'm unable to retrieve are some very large (between 1 and 2 GB) TIFF files -- a good many of my finished pieces. :-( That said, when I open Lightroom and it shows me that the files attached to the images on the screen are missing, I'm still able to preview and in fact enlarge the images and see a great amount of detail.
DO NOT WRITE TO THE RAID DRIVES UNTIL YOU'VE RECOVERED ALL FILES. This will over-write the existing files!
The app you purchased should recover all data files including TIFF files. Did you use Mac Finder to see if the files were recovered, but have been assigned a new name. DATA Rescue 4 may have recovered the files, but renamed them (000001.tif, 00002.tif, etc.) so LR will not see them. You'll have to re-import them into a new folder (name it RECOVERED) and rename them if possible to re-connect the LR catalog information with the files. Either way you should be able to recover the files.
If you still can't find the TIFF files I suggest contacting Prosoft Engineering....you paid a high price for something that isn't doing the job!
The file types that can be recovered with Data Rescue 4 are listed here and TIFF is supported - I suggest reading this link and any other user manual info available:
"Reconstructed Files will be listed in the results window when using a Deep Scan or Deleted Files Scan. The Reconstructed Files results will organize any found files by category and file type. These results will NOT have their original directory structure and will usually not have their original file names since they are found by file patterns. You will want to look through the Reconstructed Files results if you are recovering from a hard drive that was accidentally reformatted or had files that were accidentally deleted."