What's more important, a 2.8 non IS Lens or f/4-5.6 IS lens

[crowl31]

I'm about to make a lens purchase and i'm torn between 2/3 or them

Can't decided and they each have there pros and cons but are around the same price. What would you go with and why?

Canon EF 28-135mm f/3.5-5.6
OR
Tamaron 17 - 50 2.8
OR
Canon 17 - 85 IS

I have the XTI with the 430ex flash.

 

[Seefutlung]

IS only works part of the time ... 2.8 works all the time.

IS is most useful in lowlight situations or when you need additional DOF and you don't have a tripod and/or don't want to raise your ISO. IS will not work if your subject is moving (IS only stops hand shake not motion blur caused by subject movement and low shutter speeds).

F/2.8 will open up an entire new level of autofocus, quicker and more accurate, for every shot taken with the lens. In low light the extra brightness of the 2.8 makes it easier to compose and will deliver a a thinner DOF at 2.8 than available at F/4.

I am not bad mouthing IS. IS is great and I wish I have IS on all my lenses. But IS has limitations, IS is very costly ... and after all ... there is no substitute for speed.

Gary

 

[Seefutlung]

PS- the Canon 17-85, while delivering a nice focal length range also delivers extreme distortion at the wide end and the long end. I know people with the 17-50 Tammy. The build quality does not compare to the Canon ... the rotating extrenal ring is ackward and will take a bit to used to ... but that baby is razor sharp.

Go to www.photozone.de for lab testing of these lenses.

Gary

 

[icassell]

I made the choice -- and bought the Tamron -- and I have NO regrets! It lives on my camera most of the time (and I have a decent assortment of glass).