Usually I upload (import to Aperture) the photos from D800 to the iMac via cable: never had a problem with that.
Recently I was in a hurry and thought it would be quicker to use the memory card slot in the iMac to upload some of the photos. Indeed, I did that and the result was that the photos I selected for upload (=import to Aperture) were re-formatted in a way that it is impossible to read them in the iMac (Aperture), in the memory card (something was written to those selected photos in the memory card!) which is in the D800 or Epson P-7000. Of course those were the best photos (around 80 photos) of the card. I'm not able to see even the icon. The other photos in the memory card are ok.
Hereafter more details: - Lexar Professional SD card, 32GB 600x - iMac, OS X v10.8 (Mountain Lion), in the meantime upgraded - Nikon D800 - the 'new' format is still NEF and the size of the photos is around 40MB
I have tried to decipher the files with the Lexar SW: no result. With a Nikon SW: no result.
If you know what I could do or who to contact, I'd appreciate a lot. Many thanks in advance!
Will your camera read the card and write to it - that is, can you put the card back into the camera and take some more pictures that you can download as you have in the past, and will these pictures be read (can you see the images)?
If the pictures you are having problems with cannot be read, how do you know something was written to them that is causing the problem, and that the problem is not a faulty memory card?
Last week I sent a Lexar CF card to Lexar under warranty. Nothing would read the card - neither my Lexar card reader nor any of our cameras. Although the cameras recognized that the card was in the slot, none of them would reformat the card.
You might try Lexar's 24/7 "Live Chat" Support here. It took a a couple exchanges of correspondence before Lexar told me all of the information their lab would require in order to approve my returning the CF Card. Below (copied/pasted from their eMail) is the information Lexar requires, but they need to send you an RMA # before you can send them the card:
-What camera model was it used in?
-Which firmware revision is the camera running?
-What brand and model card reader was the card used in?
-If applicable, has the card reader firmware been upgraded?
-What where you doing with the card the first time this issue occurred?
-If the card was in a camera when the issue first happened, what was the camera's battery level?
-How and where do you store your cards between shoots?
-Is the card used in multiple cameras? If yes, which models?
-Is the card formatted in the camera before each use?
-Has the card ever been formatted on a computer? Mac or PC?
-Is the card recognized in any other device? If yes, which device or devices?
This happened to me twice - once the culprit was a bad card reader and I was ultimately able to get the files back using RescuePro (for SanDisk cards).
The second time, I, too, was in a hurry, and in hindsight, I don't think my MAC had completely booted. Those files were ruined, and I was never able to recover them. Going forward, I am much more patient and always wait for my MAC to fully boot before I attempt to load anything. (Knock on wood - no recurrence and it has been a year since it happened)
Good luck. This website has folks with a lot of knowledge. Hopefully one of the ideas they gave you will work.