# Canon 17-55 or 15-85



## mbbye (Dec 28, 2010)

Hi guys, I just got a 7D for Christmas and decided to give my XTi to my mother. I have been wanting to upgrade from my 18-200mm lens for awhile too, so I was thinking I'd give her that lens with the XTi since I don't have the kit lens anymore.

I bought the 18-200 right before I was going to Europe to study abroad.  At that time the ability to carry around just one lens was more  important than image quality. However, now that I'm no longer  backpacking through Europe I'd prefer to sacrifice the zoom to pick up  something with better IQ/Speed. My initial thought was the 17-55mm  f/2.8. However I've heard great things about the 15-85mm f/3.5-5.6 lately,  particularly that the 15-85, while not as fast, actually has better IQ  than the 17-55. Plus it's cheaper and covers a bit more focal range.

Does anyone have any experience with these lenses? Any other recommendations for a nice walk around lens on the 7D? My one caveat is that I want to stick to Canon, no Sigma or Tamron lenses. Thanks for your help!


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## cfusionpm (Dec 28, 2010)

If you want a constant f/2.8, then the 17-55 is a no-brainer. The 15-85 sounds nice, but that 3.5-5.6 isn't exactly awe-inspiring. I had the previous 17-85 f/4-5.6 and got some good results out of it as long as the sun was out. But it was hard to get shots with good background blur and almost impossible to get shots in low light. I eventually sold it for the 17-55.

IQ-wise, they do look pretty close, with the newer 15-85 perhaps edging it out a bit when wide open. But that "wide open" aperture is still going to be about 1-2 stops larger on the 17-55, and I know I shoot that lens at lot at f/2.8. 

If shooting in good daylight though, I know I would certainly like the range of the wider AND tighter 15-85. Just depends on what you want to compromise on.

Here's an enthusiastic reviewer's take:

Canon EF-S 17-55mm f/2.8 IS USM Lens Review

Canon EF-S 15-85mm f/3.5-5.6 IS USM Lens Review


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