Ever since I switched to a full-frame camera, I've been looking for a ultra-wide-angle lens to replace my trusty Tokina 11-16 --which is a super-solid lens, but not meant to be used on a full-frame camera.

Surprisingly enough, there's not many options for full-frame cameras out there, at least for Nikon... You have the Nikkor 14-24 f/2.8 (too expensive and too heavy for my taste), and then this Sigma 12-24.

I had read some excellent reviews of this lens, and some bad reviews as well. I wanted to see for myself, so on Friday I took the plunge, and yesterday I took the lens for a ride. This is my experience after just one afternoon of photography with it (indoors and outdoors):

- extremely fun to play with (at least until you see the results on your monitor!)
- minimal distortion (a big point considering how wide it goes -- it's the equivalent to 8mm on a 1.5x crop sensor)
- colour rendition is beautiful
- flare is not as bad as some internet reviews would make you believe
- reasonably light (about 600 grams)
- reasonably well built (or so it seems)
- reasonably fast (and accurate) autofocus

- not overly sharp --it pales in comparison to the Tokina 11-16
- definitely soft towards the edges, with one side being softer than the other!
- chromatic aberration is a huge problem, even more than other UWA lenses that I've owned or used
- light falloff is very noticeable wide open, and remains a problem when stopping the lens down
- worst bokeh I've seen on any lens
- not a very fast lens (but this I knew before opening the box, so no issues here)
- can't use filters with this lens (due to the bulbous front element)

Sample image (with some vignetting added):

f/13 @ 24 mm, 1/125, ISO 100

See it larger here.

I'm sure I'll find more pros and cons after I review and process other images. However, unless I make some unexpected discovery while reviewing images, it seems like I'll keep using my Tokina 11-16 (a DX lens) on the D700... and the Sigma is going back to where it came from.