I just bought a 5DIV and took it out to test tracking ability. I'm attaching 3 images all taken with 100-400 II. I'm not sure whether my problems with lack of sharpness as well as muddiness in the wings are from poor focus, lack of sufficient depth of field, effects of high ISO or a combination of these. I've drawn in a red square where DPP indicated the focus point to be (pictures were taken in AI Servo with either single point focus or single point plus helpers). All pictures are OOC Jpegs (still have CS6 which won't open the raw files) with no adjustments (other than adding red squares and text in Photoshop and reducing the file size to meet this site's restrictions) or cropping. The camera was set to manual with auto ISO. I have not attempted to AFMA the lens to the body yet (have requested a calibration aid for Xmas). I'd appreciate any insights this forum's experienced birders can give me. Recommendations for camera setting for these types of shots would also be welcome. I live in the Vancouver area, so the sun remains fairly low for most of the day at this time of year.