A .rtf file (rich text format) is a word processor document file.

I assume you are not using a program to download the images from the camera.
That you are dragging and dropping the files from the camera.

And somehow the photo files are being changed to .rtf files.

That sounds more like a MAC operating system problem.

Since I do not know much about a MAC, hopefully others can help.

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Suggestion:

Post your question on the new CNet Samsung Forum.
A person that works for Samsung moderates that new Forum.
Here is a link:

http://forums.cnet.com/5204-13973_102-0.html?forumID=146&tag=dir.forum

If that is not fruitful, try posting your question on the MAC Operating System Forum:

Here is a link to the MAC OS Forum:

http://forums.cnet.com/5204-6126_102-0.html?forumID=10&tag=forum.fd

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