This lens has a great potential, being in 2012 the fastest
available
at 11 mm focal length (f/2.8). Quality is not perfect at
full aperture; this is normal considering the average of the amateur
lenses. My experience with this lens has been a nightmare but now,
after having the 5th (!) sample, I got a reasonable quality lens.
Here are the main issues I've found on previous samples: 2 brand new
from China cannot move the focusing ring from the A to M position.
Fortunately, after 4 months, I succeed in getting back my money from
China, but it was hard. A 3rd one was bought used in the meanwhile, but
unfortunately it broke after a few weeks and exactly during my trip to
Norway to image auroras (very bad!). I've payed (much) to get it
repaired by official Tokina service, but the repaired lens was not able
to focus at infinity. Sent back and then another new sample arrived
(4th), but it was even worse! So another one (5th) arrived from Japan
and finally I hope to use it to image the night sky.
From the first to the last sample, I've lost 8 months!!!
Be aware of this possibility when buying a Tokina lens.
I've tested on a Canon 350D (APS-C size). The behaviour is good when
closing 1 stop, but at the corners the stars are never good. For a nice
diffraction, i.e. Sun during the day, f/16 or f/22 should be used.
Even if this lens is designed only for small sensors, I've also tested
on a 5D (full frame), at 16 mm focal (11 mm unusable due to severe
vignetting). On 5D the behavior is bad at the corners and only
acceptable at f/16 or better f/22.
Click on the image to get a full res version
Click on the image to get a full res version