Canon EF 600mm f/4.0 L IS USM Reviews

I have owned a new copy of this lens for 14 months. Mounted on a 5 series Gitzo Studex tripod the results are outstanding. Image degradation is caused sometimes by distance/haze/weather but certainly not by optical shortcomings.Max aperture IQ is not improved by stopping down. I do not regard this lens as hand holdable. It works superbly with a 1.4 EF 2 convertor and to all practical intent and purpose you cannot tell which shots are without!. The only drawback to this lens is the weight. With a 1d mk2 and tripod attached you are lugging an ungainly 32lbs which precludes carrying any other kit in the field.
I shoot surfing and this is a superb kit option however it often gets left at home unless I am pretty sure it is worth the journey. Caveat emptor. Rob Buchanan

Superb lens, even for astrophotography. Compares well even to the best premium APO refractor scopes for astrophotography. Very lightweight for a 6 inch (a50mm) aperture. Does well even if the focal length is extended to 4000mm for planetary imaging. Full comparo to a serious 5.5" aperture astronomical scope available here: