UKC

I mainly use a Canon 5D mkii for my landscape stuff but when climbing have used the 550D as its lighter and the 18-135mm kit lens covers a reasonable range . But i dont think the quality of the Canon 18-135 is that good , especially in low light I've used the 50mm 1.8 in low light with great results on it so its not the sensor. so , i'm wondering about getting a Tamron zoom to cover from wide angle to around 135 ( 200 on the size of sensor on the 550D). Anyone any thought /advice/experience .

In reply to nk: What lens do you use on the 5d? And why not use that one? I'm happy with the focal length of 24-105 on my 5d and 17-85 on my 400d. If you are to get good image quality on the range of 18-"something-long" it will for sure be a big and heavy lens and then not very practically to climb with if you already find the 5d to big. Just my thoughts, and haven’t had any experienced with tamron in the 18-135 range.

In reply to nk:

I have a Tamron 17-50 which I really do love. It makes an interesting whirring sound when AFing but it does focus quite fast (not as quick as USM mind), great image quality, and feels nicely built for a plastic lens.

In reply to Ulrik Hasemann: I've decided to climb with the 5D and the 24-105 . at least that way i can only blame myself if the pics still are crap . thanks for the input though .

In reply to nk:
mmmm difficult one, but if you are shooting low light and after a zoom then maybe this is what you need.............

http://www.dpreview.com/news/2008/1/31/sigma250500

But more seriously, sigma do a 28-105 f2.8 - 4

http://www.photographyreview.com/cat/lenses/35mm-zoom/sigma/28-105mm-f-2-8-...