Sigma AF 12-24mm f/4.5-5.6 Asp EX DG HSM Reviews

I use this lens primarily for architectural work and it is simply outstanding. The best feature is the almost total lack of linear distortion (straight lines stay straight despite the bugeye appearance). If your camera is level, straight lines remain parallel. I use this lens on two Canons, a 20D and a 5D. With the 20D, you can leave the cover sleeve on the lens for reduced flare, and you can jury rig it to accept front mounted filters if you're good with your hands. With the 5D, you need to remove the sleeve so filtration needs to revert to the Sigma's strange internal mount method. But at full frame, this lens is razor as a right into the corners. Resolution on the 5D is excellent - I see surprising detail from small objects far from the camera.

I use this lens with my Pentax *ist D. In terms of distortion, blueshift is right - there is very little at all. Sharpness is OK but not great. Stopping down to f8 or f11 helps quite a bit with this. Vignetting can be a problem at 12mm with the lens hood on, but without it you are more prone to flare. The amount of turn of the focus ring required to go from, say, 20 metres to infinity is very, very small, which unfortunately means that tiny focussing errors make a big difference to the pic if you're not careful. Overall, a great lens for landscapes and architecture if used carefully.

Bought as part of a package, so can't specify price exactly.

According to Lightroom I use this lens for about 80% of my photography. I love it. Pretty sharp if stopped down, mad stretching at the corners on full frame but generally well controlled distortion. The only thing that bothers me about it is the flare. Big fat blue blobs. In daylight photography they creep in at any excuse. Stitched panos can have blue balls everywhere. Apart from that, it offers anazing value for money. Recommended.