Maybe I should rephrase my question. Is the 24-105 going to work on a 3ti or is it made for a ff canon ? Finally retired and would like to shoot with better lens than the kit lens camera came with...Any help would be appreciated !
What kit lens did your camera come with?
All Canon full-frame lenses work fine with crop-body cameras. Of course, its field of view won't be nearly as wide on a crop body as on a full frame, so depending on how much you shoot wide angle shots, you might be find yourself preferring its crop-body equivalent, the EF-S 15-85. Alternatively, you might consider pairing the 24-105L with an EF-S 10-22 for when you want to shoot wide.
The 24-105 is a great lens, but I found it to not be wide enough as a general purpose zoom on my 7D (equivalent full frame focal length = 38mm to 168mm). The EF-S 15-85mm is similar in image quality to the 24-105 and gives a more useful focal length range for a crop body (like your T3i).
In my experience, the EF-S 15-85 f3.5-5.6 and EF-S 17-55 f2.8 are the best general purpose lenses for crop body cameras. The 17-55 being preferred if you need a faster lens for low light photography. The 15-85 has better focal range, but a smaller aperture - great for landscape and outdoor photography, but its requires flash for low light or indoor use.
« Last Edit: July 12, 2013, 06:06:35 PM by bholliman »
EF Lenses: 50mm STM, 300mm f/2.8L II IS, 16-35mm f/4L IS, 24-105mm f/4L IS MkI, 70-200mm f/2.8LIS II 600EX-RT (x3), 1.4xIII and 2xIII extenders
EF-M Lenses: 22mm f/2, 15-45mm, 55-200mm