The Sigma AF 12-24mm f/4.5-5.6 HSM DG II is the only "one size fits all" (formats) ultra-wide zoom lens on the market. It can give you decent results and truly extreme views on full format DSLRs and it is very good along across the more "conventional" zoom range on APS-C DSLRs.

If you're into high quality glass, this is the kind of lens you can get lost in. Build quality is exceptional, performance is outstanding and…I'm getting ahead of myself, but you'll see the world in a whole new way when you use this lens.

I do not plan to create a full Sigma 12-24mm f/4.5-5.6 EX DG HSM Lens review - hopefully the standardized results for this lens will be helpful to you.

This ultra-wide angle zoom lens from Sigma projects an image circle big enough for full frame digital/35mm and is still very wide on a cropped sensor. We take a look at how it performs.

Enormous field of view; Amazing control of distortions; Solid build quality with good protection of front element

Difficult to use front mounted filters (Though not impossible; Bulbous front element needs careful handling

Sigma 12-24mm f/4.5-5.6 EX DG HSM is one of about half a dozen ultra wide zoom lenses in Sigma's modern lens lineup. This is also one of the widest full-frame zoom lenses available on the market at this time (there are a couple of 'wider' APS-C type lenses offered by Canon, Tokina as well as Sigma...

I used to have a Sigma 15-30 before purchasing this lens, but I needed a larger angle coverage for some architectural pictures. This lens has no real distortion even at 12mm, and it's quite sharp if you use it at f.5,6 and over.

Very wide; Sharp over f.5,6; No distortion at all, a miracle

Needs to be stopped at f.8 and over for the best results