The filename prefix my camera (Rebel T1i) started storing the images on my SD cards with the following naming convention: _MG_nnnn instead of IMG_nnnn. I can't find where this convention is set. Can anyone help?
That did the trick. I am not sure how I even changed that setting. It was not intentional. I hope it does not screw up the images that were taken with the setting that way. I have not tried post-processing them in any way and they seem OK otherwise. ...