Tamron 17-50 f/2.8 (non VS) vs. Canon 17-40 f4L

[GrantH]

I'm all but decided on these two lenses for my next purchase. I've read a bit on both and from reviews they seem decently equal, but surely the price isn't simply based on the name for Canon.

Can someone pinpoint the main differences between the two?

[Ads]

[Dao]

Canon pros:
- Faster AF
- Better built quality
- Weather resistant
- Canon branded lens, better compatibility with the future camera bodies.
- EF mount, works with full frame/film or cropped sensor bodies.


Tamron pros:
- Lower cost
- Smaller filter thread size (lower filter cost)
- Lighter in weight
- Larger max aperture. (f/2.8 vs f/4)


This is what I can think of now.

[TCampbell]

Basically what Dao said. But just to be clear, the Tamron is made for APS-C size bodies only -- if you had a full-frame body it wouldn't work. Basically it's the competitor to the Canon EF-S 17-55mm f/2.8 except without the image stabilization.

[GrantH]

What about quality though? I probably won't ever step up to a 5D or similar, but I don't want to spend 450 for a "sub-par" lens, when 750 would get me a great lens.

[Dao]

As for build quality. I do not own the 17-40L lens. But based on the other Canon lenses that I have include 1 L lens, it is going to be better than the Tamron. (I have the 17-50mm non-VC Tamron)

I expect the zoom ring and focus ring on the Canon 17-40L feel smoother. Especially the Canon is a Full Time Manual focus (FTM) lens. My Canon non-L and L lens that has the FTM, the focus ring feel very smooth. (Except the 50mm f/1.4, it is better than the Tamron, but not as good as my 85mm f/1.8 and 70-200mm f/4)

As for the optically quality, I have no complaints on my Tamron. And it is on par with some of the higher price lenses in the same category based on the reviews I'd read.