Are the files smaller too?
I think that, when you view the thumbnails before download, you are viewing them remotely. If they are corrupt after download, then it's the download process which has gone wrong.
Did you use Adobe Photodownloader, ot some other method? Did you download from the card or the camera?
The files were the correct size after downloaded them and I used the PS5 Bridge program to dowload directly from my camera. I have spoken to Nikon and Adobe about this problem and both seem to agree that the files became corrupted during the download process. Nikon suggested using third party software to recover the files from the SIM card, which I have now done, but out of 120 files, there were still 6 or 8 files that I couldn't do anything with. the strange thing is that I could view all the files with the Nikon NX2 software, but as soon as I tried to do anything with them, like converting them to a jpg, I got a meaasage saying that the file was not recognised! So panic over for this particular issue, but I am still curious to know if this is a common problem. I suppose if nothing else, I have learned a valuable lesson, which is not to delete pictures from the camaera until after they have been successfully transfered to the computer. Thanks for your interest in my tail of woe!
There are several points of note here:
1. Raw files contain a small embedded jpeg, created at the time of capture. This will be what you can see in NX. Just because you can see the preview, it doesn't necessarily follow that the rest of the file is not corrupt. File size is not an indication of integrity, as some of the file could be corrupt.
2. It's worth checking that Bridge can create HQ thumbnails and previews from your raw files before deleting them from your cards.
3. From my experience in reading these forums, most download problems seem to occur when connecting directly to a camera. I'm not sure why this is, but it might be USB related. I do read of these problems from time to time, but I wouldn't say it was a common complaint. I always recommend using a good card reader, as this seems more reliable.
Good advice. Thanks alot. I will connect the card directly to the computer in future. Otherwise, I will uncheck the box in Bridge that deletes files after the transfer has completed. Thanks also for explaining why it was possible to see the image in the NX software.
Just to be a bit of a stickler for terminology, a SIM card is not the same as the flash card on which photos are stored - unless there's some new camera phone I don't know about that combines them somehow.
You are absolutely right Noel. My mistake.