15-85mm f/3.5-5.6 vs 17-40mm f/4L for a crop camera

[LACityPhotoCom]

I really do not understand why people use the 17-40L on a crop body. I had one before on a crop body and learned from my mistake. My images looked no better than my 18-55mm kit lens! Stopped down to F/8 or so, performance is identical, as most lenses are--Ls included too. If you're going to get a standard zoom for your crop body, get a fast-aperture f/2.8 zoom that way you have low-light capabilities. F/2.8 vs F/4 doesn't seem to make a difference but once you get 2.8 lenses, you can't go back. It's just a nice luxury to have.

But if you're on a budget, consider a wide fast prime like a 28mm 1.8. Forget any slow zooms. Thats what your $100 kit lens is for. (The kit lens is actually a great performer) just have to stop down.

 

[JTPAIN]

Sorry to post a question within another post - i hope the OP doesn't mind?

Wouldn't a fairer comparison be

17-40L vs. 17-55 IS

Between these two - which would 'win'?

 

[Loswr]

Sorry to post a question within another post - i hope the OP doesn't mind?

Wouldn't a fairer comparison be

17-40L vs. 17-55 IS

Between these two - which would 'win'?

The 17-55mm, except for build quality.