I purchased a Canon 580EX about 3 years ago and finally used it (yeah, I know) on my recently acquired EOS 5D Mark II. Using the separate flash is new to me so bear with me. I was asked to shoot a wedding for my business partner's son over the weekend. I did some experimenting with the flash/camera combination and for the most part, the pictures turned out well. What I noticed was, some of the pictures are well lit while the next picture in line from basically the same angle was dark. The flash did go off and I had it set to E-TTL. Most of the time the camera was set on "P" which meant a 1/60 second shutter speed. I did go to TV and set it at 1/100 or 1/125 for a few shots.
I went to the menu of the EOS 5D Mark II and in the flash menu tried to reset or clear the settings of the flash, but got an error message about the flash is not on or compatible. Any ideas as to which units are compatible?
Michael R. Douglas