I'm planning to buy a wide angle zoom soon but I can't decide on buying a used 17-40L or a new Sigma 18-55 2.8. I read reports stating that the Sigma provides results that are close to those of the 17-40L . I like the fact that the sigma has a max aperature of 2.8. I'm sure that would be useful for indoor shots. I dont do much indoor photography but I plan to start. At some point I would like to shoot weddings so I need something that can be used for that purpose as well as landscapes. Please help me choose.

if you can afford the canon, get that, then buy another lens for low light situations (aka 50mm 1.8). if money is an issue though, go sigma. even a used 17-40 is more expensive. i'll probably end up buying that sigma actually. i've heard many good reviews and looked through alot of lens tests. it's a very nice lens.

I had the 24-70L, but sold it once I saw the results from the 18-50. But then I borrowed a friends 17-40 and 24-70 to be able to pit them all against each other. I posted it about a week ago. Here is the link

Good luck

I recently bought the Sigma 18-50 f2.8 EX DG... I absolutely love it. Now, if only I also owned the Canon 17-40 I could give you some useful information.

So far, I've found the shots to be very sharp, nothing that would make me say they weren't perfect (except for things caused by my skills). It does have the Sigma warm color, though. If that bothers you, you should spend the extra money for the Canon. And on that topic, I bought my Sigma new from Sigma4Less for $419... best price I could find on a used 17-40 was $575. I really couldn't justify the extra cost for pride of ownership. But that's just me. If I were shooting professionally, I would most likely be using all L glass, too.

I had both and ended up selling the Canon. Sigmas have QC issues so you sometimes have to search for a good one. The Sigma I have is very sharp - on par with the 17-40L. It's focusing is a little slower and louder and not as precise as the Canon and It also has slight fringing(sp), but it is faster, smaller/lighter, and goes to 50mm.