CANON 400MM DO II FIRMWARE UPDATE HELPS CALM R5

A recent update to the firmware for the Canon 400mm f/4 DO IS II appears to have fixed a problem reported by some users where the lens stabilization would jerk the viewfinder image at times. The firmware notes had included a bit indicating that it “Fixes a phenomenon, in rare cases, the IS mechanism may cause the image to jump.”

At least one forum dweller on Fred Miranda indicated that it appears to have fixed the problem so far.