TOKINA ATX 280 F2.8 REVIEW VS CANON USM 28-135 WITH IMAGE STABILIZER
When I bought my Canon Camera, the first lens I purchased was the 28- 135 . For several years I took lots of pictures and obtain a good quality. In order to improve quality and get sharper images I decided to purchase Tokina ATX 28-80 f2.8 zoom. The reasons were:
 Very well constructed  Inner focusing system, lens does not change it size while zooming  Better color correction according to Tokina  The company might include Hoya experience in building their zoom  Very heavy which should mean that the quality of the lens is better.
First I bought a film roll and went out to a park to take pictures. When I saw the print none of them where in focus. I got really furious and could not understand what happened.
Another day I asked a friend an Eos 300D Rebel to make a test and try to identify which was the problem. Test was done under the following conditions. Camera: Eos 300D ISO 100 Flash WB: Flash No filter in front of the lens was used to avoid any color correction
a) Depth of field
1-Focal length: 28 and 35 F 2.8 and 3.5: The lens has better resolution than canon 28-135 but the object focused should be under 2.5 mts. For objects or subjects which are more distant than 3 mts use f 5.6 or smaller. If you don?t do this you won?t get images on focus. TRUST ME!!
2-Focal lenght: 50 and 80 F2.8 and 3.5: The lens does not work in this combination, no object at any focusing distance is in focus. TRUST ME I HAVE IMAGES TO PROVE. F8.0 or smaller at 2.5 mts, better color and sharper images than canon eos 28-135 mm
b) Color balance.
Tokina has cleaner whites, but it?s more contrasted than Canon, so you loose detail very easily in highlights. Canon 28-135 has whites with more cian , but the advantage is that you do not loose detail in highlights, just make an easy color correction with any editing software and solve the problem.
c) Weight. Tokina: An f2.8 lens is supposed to be heavier than a f3.5 lens. There is no doubt about that. But as Tokina does not work at f2.8 , weight becomes a trouble because the lens is not stabilized. It is very difficult to obtain sharp images with Tokina at 1/30.
d) Sharpness Tokina is sharper than Canon, but it?s more contrasted and tends to loose detail in highlights, so if you do not have any detail, sharpness is worthless.
Tokina works better under very limited conditions. If you want to achieve good images , you have to remember this rules if you don?t want to be disappointed with your photos. Canon 28-135 is more reliable, you won?t get the sharpest image but you will get it. You can trust the lens and relax because you won?t have problems. My advise for those searching f2.8 lenses, is to save more money and by Canon 24-70 F2.8 zoom lens.