I was thinking recently if/how/why I can replace my kit lens (18-55mm) with something a bit better optically without spending too much. Thinking about it sensibly though I figured it would have to do around the same focal lengths as I wouldnt be expecting to buy anything else anytime soon e.g. the Tamron 28-75 is nice but I'd need to pair it with something like the Sigma 10-20 or Tamron 12-24 which frankly isnt likely to happen*

Two obvious candidates came up then...

Sigma 17-70mm f/2.8-4
Tamron 17-50mm f/2.8

Which one would you go with though? (I already have a Sigma 50mm f/2.8 macro and a Tamron 70-300mm)

The Tamron I'm led to believe is the sharper of the two and offers f/2.8 throughout the range. I would be left short from 50-70mm though. The Sigma on the otherhand goes to 70mm giving me full coverage from 17-300mm but lacks the constant aperture.

Whadyathink?

*although I'd love to take one on the wedding/honeymoon to Italy in September

Tamron, IMHO. I'd rather have the f/2.8 all the way along.

Do you really feel the need to cover every mm of focal length?

No. But It is worth considering IMO whether the extra 20mm of the Sigma is more or less valuable than the constant f/2.8 aperture of the Tamron.

With that in mind, think about the situations you'll be using the lens in.
Are you really going to need the extra 20mm? Personally, I'd do what Alex said and get the faster glass over the extra 20mm, but then, I've no idea how you'll be using the lens.I do. I don't know why, but I just do. *shrug*

Mark

Yes, with your current number set on flickr I can see that you do.

(8+)

Mark

I have an 17-85mm lens for my camera. The one which I find I use the most though is the 10-17mm.