Article Summary:

Canon has released updates for the EOS 1D Mk IV and Rebel T2i (550D.) In both cases, the firmware is labeled v1.0.8 and primarily fixes:

“a phenomenon in which the set aperture moves unexpectedly when shooting movies in manual exposure mode using some Canon lenses (such as macro lenses). Supplemental Information: This phenomenon involves the aperture of the lens moving unexpectedly when the focusing ring moves (during focusing). Please note that aperture values also change when operating the zoom ring of a zoom lens that has variable maximum aperture values.”

The updates are available for download now.