QUOTE(sukhoi37 @ Nov 7 2010, 07:49 PM)
Don't waste your money on 17-40f4L.
It is for FF not for cropped.
IQ comparison?
Tamron 17-50mmf2.8 vs Canon 17-40f4L:
http://www.the-digital-picture.com/Reviews...p=0&FLI=0&API=2I find it funny on the ppl using 1740f4L with cropped body.
The lens range is short, f4 is small, not sharp and expensive.
Maybe it's the weather sealing feature they looking for.

Well, it depends on what you want the 17-40 for. Some go for the L, some go for the specs
I am a 17-50 2.8 user but change to 17-40 2 months ago. Maybe it is because of the work line that I do
In many situations the 17-50 was unable to cope at the speed I was going and the 17-40 was just perfect. First point is USM
Secondly is the colors and sharpness. I felt I could get better results at F4 over the tamron. I knew 17-40 wasn't the sharpest out there
But it gets the job done and lastly is weather sealing. In my work, rain or shine, you must still shoot
There are 101 lens rain coat out there but I felt I don't need it if I have the 17-40
I am using the 17-50 on crop, 7D to be exact and it yields much more consistent results over the 17-50 overall.

@kimkoon: Do take note that the Sandisk extreme III is a much older version and it have been replaced with Sandisk Extreme
The Extreme IV is replaced by Extreme Pro
This post has been edited by azrinarizz: Nov 7 2010, 08:43 PM