09-24-2017 05:17 PM
Are you sure about that 2nd one? I don't see a sigma 18-35 f/2.8 at B&H.
Any sigma lens made for any modern Canon will fit your Rebel. Rebels are a crop sensor camera and their mount takes any EF or EF-s mount lens in Canon language. In sigma they call that DG and DC mount lenses.
If you are buying a Sigma lens be sure to get a version made for Canon. Sigma also makes versions for Nikon, Sony, and others, and those would not work.
09-25-2017 11:28 AM
The Sigma 18-35mm f/1.8 DC HSM Art Lens for Canon is a fantastic lens. It is for Rebel only, it is not made to work on a full frame camera.
I am not aware of a f2.8 version of the 18-35mm but I am not the definitive authority on Sigma lenses. There was a old version of a Sigma 17-35 mm F2.8-F4.0 EX DG HSM. I can't comment on it since I never used one but I would bet the farm it doesn't hold a candel to the Sigma 18-35mm f/1.8 DC HSM Art Lens for Canon. Not many lenses do !