Hi- have a Canon 50D and went to download to Macbook and now the files show .igy in front of image numbers- get message saying cant open them- this is all the info I have as a friend was using the camera and there not sure what they did to it- any help would be appreciated
When you save in "RAW+JPEG" format you actually get two seperate images... a ".CR2" (RAW) as well as the JPEG image.
Apple supports camera raw updates as part of it's OS updates because they use the same raw processing libraries for iPhoto, Aperture, Preview, and Quicklook on the Mac. This assumes the Mac knows it's a .CR2 file. If it doesn't have a .CR2 extension then it likely wont attempt to display it.
While I don't own a 50D, you should have a function to reset the camera back to factory defaults -- which would clear anything your friend may have changed when they were using it.
Are you sure images are showing "igy" in front of the file number?
They should show IMGxxxx.JPG or IMGxxxx.CR2 (if the camera is set to use sRGB color space)
_MGxxxx.JPG and _IMGxxxx.CR2 (if the camera is set to use Adobe RGB color space).
When shooting RAW + JPEG, you should see one of each for every file number.
In all cases the "xxxx" would be the sequential file number between 0001 and 9999.
50D cannot shoot video, so there are no types of video files possible.
There is no way to prevent 50D from using these file number conventions. In other words, nothing can be changed in the camera by the user... except the choice of sRGB or Adobe RGB color space, which determine whether an "I" or an underscore are used at the beginning of the file name.
If the file name is showing something different, that change must be happening when you are importing the images from the memory card to your computer. What method do you use? Is it set to rename the files during import? (I just use a drag and drop to copy or move the files from the folder on the memory card to a folder on the computer that I've prepared in advance... In other words, I don't use any software-based import.)
If the file extension has been changed accidentally, you should be able to edit it and change it back. Don't mix up the .CR2 and .JPG though. The CR2 files will always be the much larger of the two.