Here is a link to a thread about the tokina 12-24. I considered the Sigma 10-20 and realized I needed 20-24 more than 10-12. It's strong as a tank and the optics are amazing.

http://www.fredmiranda.com/forum/topic/725373

AJ Nadershahi wrote:
Surprised no one has mentioned Nikon's incredible 14-24. Amazingly sharp and low distortion, which would be important for architectural images.



Yea, this is great on an FX camera and if 14mm is wide enough on dx as well.
However, the OP asked for wiiiiiide

AJ Nadershahi wrote:
Surprised no one has mentioned Nikon's incredible 14-24. Amazingly sharp and low distortion, which would be important for architectural images.



It was mentioned at the top of the threat, it just seems the other lens are more popular due to their nice price tag

Tokina 11-16
tested and going to purchase it very soon

You can't go wrong with the Sigma. It's super sharp except for the extreme edges which isnt critical in most landscape work. Most of the shots in my 'Seascapes' gallery are shot with it. I was sketched by all the reports of low quality, and I am picky. I can tell you that I have been very happy with both it's operation/performance, and it's build quality.

The Tokinas a great to, particularly if you enjoy correcting CA on every single shot you process.

tomb18 wrote:
I have the sigma 10-20 and I find it outstanding.
Here are 2 shots you can look at

Aaron Macomber wrote:
You can't go wrong with the Sigma. It's super sharp except for the extreme edges which isnt critical in most landscape work. Most of the shots in my 'Seascapes' gallery are shot with it. I was sketched by all the reports of low quality, and I am picky. I can tell you that I have been very happy with both it's operation/performance, and it's build quality.

The Tokinas a great to, particularly if you enjoy correcting CA on every single shot you process.

I plan to shoot architecture so sharpness to even the extreme edges is important to me.. Guess i'll have to keep looking.

kierra wrote:

I plan to shoot architecture so sharpness to even the extreme edges is important to me.. Guess i'll have to keep looking.

Again, I think it's worth considering Nikon's 14-24. It may not be quite as wide as a 10mm or 12mm, but it is hard to beat its edge-to-edge performance at the wide end.