After parting unwillingly with my Tamron 11-18mm (an excellent lens), I purchased a Tokina 12-24mm AT-X 124 Pro DX so that I have more reach towards 28mm-end, where my latest-addition secondhand Tamron 28-75mm f/2.8 takes over. I could have bought the Sigma 10-20mm f4-5.6 which is cheaper and wider, but from experience, I don't use a lot at 11mm. In fact, when I tried to sell my Tamron 11-18mm and wanted to post some image samples to demonstrate the coverage, I found mostly images taken at 14mm and above.

It took me quite a while to inspect the lens at the shop, because the wide angle glass elements tend to make each reflection look like dust spots. The first one the shop staff gave me really had a speck of dust embedded inside the rear element. After much persuasion, the staff brought out a 'reserve set' for me to try out. The lens is currently on promotion: it comes with a whole bag of freebies including a photographer's vest (no one uses them anymore nowadays), couple of cleaning kits (including LENSPEN, Giottos), a light-weight no-brand tripod that is surprisingly feature-packed, and of all things, a 64MB Compact Flash card (anyone still uses that in 2005?). Anyway, great buy at a great price. (...read more)

It didn't take me long enough though to love the new Tokina lens. Some of the things that I like about it, compared to Tamron 11-18mm, are:

- feels that the body is made of a thicker and firmer plastic
- heavier
- tight zoom rings, doesn't feel fragile
- adequate handling space to screw in lens without touching the zoom or focus ring 
- bigger front elements (requires filter to make sure no smudges)
- faster focus
- constant aperture
- focus ring doesn't turn during focusing
- premium plastic lens hood with internal black velvet coating

Exposure Variance?
Having read on some forums that the Tokina 12-24mm exhibits under-exposure at smaller apertures, I made a few casual test shots outside my residence and compared with Tamron 28-75mm. I couldn't believe it but it seems that my new lens is under-exposed by 0.5 stops even at f/4! However, further tests with my other lens seem to suggest that it's the Tamron 28-75mm that is over-exposed by 0.5 stops! See test shots:

Not sure if I should be impressed with the Tamron 28-75mm or not. I do prefer the higher exposure of Tamron 28-75mm compared to other lens.

Focus Ring
One good thing about the focus ring is that it doesn't move during focusing. However, it also means that when I switch to manual focus on the camera, I can't turn it either, unless I engage the MF mode on the lens by pulling out the focusing ring. Somehow I don't feel comfortable doing this too often, as I felt the mechanism is a cheap way to disengage the focusing ring from the internal focusing element. On one hand, it's good that it's tight but being too tight I may over-pull and spoil it (?). On the other hand, it may become loose after lengthy wear. I would prefer the Nikon kit lens where the focusing ring does not turn yet you can override by turning it manually.

Optical Quality
I have not gotten into much serious shooting the Tokina lens officially (my next wedding assignment is in 2 weeks time). But as I did some test shots, I felt that this lens has less distortion than Tamron 11-18mm and gives me more coverage. Apart from the fear of under-exposure, I am otherwise very happy with the quality. Slight purple fringing is noticed but not as bad as the Sigma 17-50mm f2.8 that I tested at the same shop I bought this Tokina lens.

Summary
This lens won me over with its:
- superb build
- lesser distortion
- plastic lens hood with velvet coating on the inside
- fast focusing (but not super-speed)
- 2-year local warranty
- reduced retail price

This lens could be better if not for its:
- AF/MF push-pull mechanism (I only tried enabling it once)
- slight chromatic aberration (not-critically bad but it's there on some images if you look hard)
- velvet coating on the lens hood could potentially attract dust, making it a maintenance issue

Ken Rockwell strongly recommends this lens after the Nikon 12-24mm. Read the lens comparison here.