Canon 17-55mm or sigma 18-35mm ?

thamer08 wrote:

Hello

I am planing to get new lens sharp and high IQ and I found the best choice for my 450d these two lenses

they have the same price on amazon and i am confused of decide which better to me

canon 17-55mm f2.8 is usm

the good

-better zoom range for many use

- has IS

the bad :

- build quality is not good as L lenses

- there are other lenses with similar range and aperture but more less price

sigma 18-35mm f1.8

the good :

- it is new brand compared to canon 17-55

- 1.8 is faster and better in low light

- buying it is similar to buy many prime lenses with f1.8 (24mm,28m,30mm,35mm)

- better build quality

the bad :

- very heavy even more heavy than long zoom lenses !

- small zoom rang

- no IS

- I read there is some focus issues with sigma lenses and bad copies !

sorry for the language because the English is not my native

My Issue with the 18-35 is how often are you to actually shoot at very wide aperture at normal to wide zoom settings. My take is that narrow aperture is mostly effective with a single subject, as with multiple subjects it can be tricky to get all of them in focus at once.  Yes, a wide is a bit less demanding than a tele for this, but it is still a factor.

If there was a good ~40-120 fast lens for APS-C, that might make the 18-35 more interesting to me...  There is a sigma, but it is as big as a FF 70-200 so that doesn't quite fit the bill.

I would really like a 40-120 f2.8 or a 40-80 f2.0 as a APS-C portrait zoom.