Sigma 17-70 or Tamron 17-50?

[barnaby_harding1]

<p>Hello!</p>

<p>I am finally getting to the point where I am preparing to upgrade my 18-55 IS kit lens. Ideally I would like a 15-85 to give a bit more wide-angle and zoom capability, but there is NO WAY I can afford it ; (<br>

So - I spotted the Sigma 17-70, which appears to have good reviews, and the Tamron. The Sigma would end where my current Tamron 70-300 picks up, so that's handy. Questions is - how do people feel about the Sigma? AND is the field curvature problem that Photozone in particular identified on the Tamron 17-50 really that bad, or is it a pain in the bum!<br>

All opinions and advice, as ever, very gratefully received.</p>

[jim_j2]

<blockquote>

<p>how do people feel about the Sigma?</p>

</blockquote>

<p>What I have read regarding the compatibility and frequency of issues with the Sigma lenses , . . . well I just don't have the desire to own one to date. I'm sure like every product, there are good and bad!</p>

<blockquote>

<p>is the field curvature problem that Photozone in particular identified on the Tamron 17-50 really that bad</p>

</blockquote>

<p>Not quite sure I follow? Of course, I don't get too involved in the technical aspects of lens comparisons other than their reputation of reliability, sharpness and affordability when comparing apples to apples.<br />And, none of my thought process is scientific by any means. So my .02 may not be worth anything.</p>

<p>I do however own the Tamron 17-50mm f/2.8 AF SP XR Di II LD IF. I purchased it used, and have been very happy with the results it has produced over the past year and a half. <br />I find some of the images the Tamron is capabile of producing is nearly as good as those produced by my two Canon L's and my EF 50 f/1.4 on a "day to day use" comparison, and realizing that all my lenses are intended for different uses.<br />I purchased the Tamron while considering the Canon EF-S 17-55 f/2.8. The Tamron was less than a third of the price, and had good overall reviews that I had read.<br />The Tamron is my only third party lens to date, and I have been very satisfied.</p>

[arie_vandervelden1]

<p>The field curvature is a problem when you shoot test charts. In real life it's not a big deal.</p>

[bj_larsson]

<p>As for the gap from 50 - 70 mm: I shoot the Tamron (different body) and I currently have a "gap" from 50 - 70 mm with my lens setup. It hasn't bothered me.<br>

I'd suggest you look through some of your "winning" shots to see how often you shoot in the 50-70mm range to see if you'll be bothered by it. If you find yourself frequently shooting right around that range, it may be a concern. I find that I adjust my shooting style based on what I have mounted.</p>

<p>Best of luck.</p>

[jack_nordine]

<p>Check out the Photozone review on the new Sigma 17-50mm 2.8. You may want to consider this lens as well.</p>

[barnaby_harding1]

<p>Jack, the original non-VC version sounds really good - thanks for bringing it to my attention. Just need to save the pennies now! </p>