SD card class causing problems viewing photo files

Hi,

I really hope one of you very clever people can help me, I am also a novice to intermediate when it comes to this sort of thing so if I am vague or have have made mistakes in this description my apologies!

I have a large number of photos on a 32GB SD card a friend lent to me for a trip abroad as I was after a large capacity card to use with my DSLR. Now that I'm reviewing the photos, about half of them stored on this card cannot be opened in any of my usual photo viewer programs, as an example, Windows photo viewer states that it does not support the photo format or I do not have the latest version of photo viewer (which I do so that's not the problem). Photoshop also states that "an unknown or invalid JPEG marker type is found".

I used the card assuming it was suitable as this friend is a photographer and videographer, but on closer inspection it is in fact a class 10 and not a class 4 as I am used to using. As is always the way, my photographer friend it belongs to is now away for 2 months travelling and I can't seek his advice!

Is this difference in class be causing this problem? And more importantly, is anyone aware of anything I can do to be able to open these photos? They are from our possibly once in a lifetime trip to Australia and our engagement so it would be a real blow if these are lost permanently!

Thank you very much for taking the time to read!

Hi mbridges,

Simply stated a class 10 card is a faster card than class 4 card. So that is only a speed classification and for still images and Standard Definition Video a class 4 card is more than sufficient. This classification has no relevance to your problem.

What make and model is your DSLR?

Can you review the problem shots on your camera?

Did it come with any software with which you can straightaway download the contents of the SD card from the camera? Have you tried it?

Well, copy all the data on your SD card as it is into another media and keep it as a backup.

Do not try any repair utility unless you are sure that the photos are corrupted.

Since you mentioned Photoshop and the error message "an unknown or invalid JPEG marker type is found" it could well be a format problem. Check whether this thread helps How to Fix 'Invalid JPEG Marker' or 'Not a Valid Photoshop Document' - Yahoo! Voices - voices.yahoo.com

You may also make your google search on that error message.