Am I ambivalent about this lens? Well, yes and no. It does what it claims very well: its the widest aperture zoom lens you can put on a full frame camera. And 12mm on a full frame is spectacular: be careful in framing or you’ll see your shoes in the shot. Seriously. Its reasonably sharp in the center, even wide open. The corners and edges require stopping down to f/8 to sharpen up, and even then the corners are going to show some distortion at the wider end. If you want razor sharp, this isn’t the lens for you. If you want good acutance and a dramtically wide perspective, this is great.
As an aside, we often get asked with this lens to “check for a sharp copy because I saw online that there’s a lot of variation”. There is a lot of variation, but most of it is camera-to-camera: because of tiny tolerances in lens mounts a given copy may be a bit softer on one side on camera A, on the other side on Camera B. It happens with ultra-wide lenses. So if you’re a pixel peeper, this is NOT the lens for you. Promise. Get the Nikon 14-24 instead.

Try and Buy Program: Lensrentals is pleased that our friends at SuperdigitalCity have made a special offer for our customers renting this item and considering purchase. Simply email your Lensrentals Invoice number to SuperdigitalCity and they will email you back a coupon code good for $41 (one week’s rental) off of the purchase of the Sigma 12-24 f/4.5-5.6 lens.

Please note: We do not suggest using a screw in filter for this lens due to the vignetting.