Anyone have any experience with this Sigma 17-70?

[radiotyson]

<p>Thinking of this lens as a replacement for my pentax kit 18-55 f3.5<br>

<a href="http://www.amazon.com/Sigma-17-70mm-2-8-4-Pentax-Digital/dp/B002ZNJB3M/ref=cm_cr_pr_pb_t">http://www.amazon.com/Sigma-17-70mm-2-8-4-Pentax-Digital/dp/B002ZNJB3M/ref=cm_cr_pr_pb_t</a></p>

<p>Anyone have any experience with this lens they could share?</p>

[shaloot]

<p>Our local lens guru Hin Man speaks very highly of this lens. Funny you mentioned this post, cause I have been really looking at getting this lens and I can't help to think why get the Pentax 17-70? Sure, it's f/4 constant... but f/4. And it's more expensive!</p>

<p>Anyways check out Hin's thoughts of this lens on his blog:<br>

<a href="http://www.techtheman.com/2009/09/pentax-1-lens-choices.html">http://www.techtheman.com/2009/09/pentax-1-lens-choices.html</a></p>

 

[miserere_mei]

<p>Note that Hin's comments are regarding the older f/2.8-4.5 screwdrive autofocus model, while Tyson is asking about the new f/2.8-4 HSM optically stabilised model. Similar, but different lenses.</p>

[ken_yee]

<p>afaik, the HSM model hasn't been released yet...or at least I've never seen anyone post that they bought it ;-)</p>

[terry_fishlock]

<p>I have the older non HSM version and love it, so much I just sold my Pentax 16-45 because I like the Sigma better. It's a great walk-round zoom and the 2.8 at the wide end can be very useful</p>

[don_laing1]

<p>I bought the screw drive version after my Pentax 17-70 suffered the familiar SDM failure. The Sigma is wonderfully sharp at close focus and generally better at the 70 end than the 17 end. My frustration with it is that mine back-focuses at 70mm and front-focuses at 17mm. So even with my K20D, using the autofocus adjustment is not a practical solution. That's a pity as otherwise the lens performs very well. The lens is also solid and well constructed.<br>

I'm interested in the new 17-70 OS/HSM version as my 50-200 OS/HSM has only very minor BF/FF issues, which may mean Sigma are paying more attention to the autofocus issue in their newer lenses. That extra half stop of speed at 70mm would be welcome too.</p>

[pbarnes]

<p>I have the older version of this lens - it is a good lens. Don, how does a stabilised lens work with a camera with sensor stabilisation like the K20D?</p>

[don_laing1]

<p>Hi Peter, You have the choice of using the in-body SR or switching that off and switching on the Sigma lens SR. My finding with the OS 50-200 was that the in-lens was only slightly better than the Pentax sensor SR.<br>

My experience was supported by a review of the Sigma lens where they found it only gave about 2 1/2 stops of reliable improvement. I generally find the Pentax sensor SR gives me about 2 stops improvement for tele lens shots.<br>

Despite that I find the new Sigma 50-200 a great improvement over the little Pentax 50-200. It is larger and heavier than the Pentax DA for sure, but the trade-off is that make it easier to hold steady (more inertia). It also seems to have better image quality than what I got with the DA. The HSM motor is much quieter than using a screw-drive lens such as the DA.</p>

 

[michellemandat]

<p>The Sigma f2,8-4,5 is a very good and sharp lens slightly warm. Indeed the new version can't be bad but optical stabilizer is not really necessary with the most recent cameras like K10/20/7.<br>

all pics with Sigma 17-70 f2,8-4,5:<br>

<a href="http://m.lemandat.free.fr/coppermine/thumbnails.php?album=54">http://m.lemandat.free.fr/coppermine/thumbnails.php?album=54</a></p>

[dwwade]

<p>I bought this lens for my istD, and now it is the primary lens for my K7. f2.8 disappears around focal length of 21mm or so. Beyond that I'm very comfortable with the lens. The price of 72 mm filters are a bit of a spank, but that comes with the f2.8 aperture. Pentax's version is a constant f4.0, if I remember correctly. I say version because somewhere I read online the basic design of both lenses have striking mechanical similarities, with the original design leaning toward Sigma. Of course, no manufacturer would ever admit to licensing technology, so the truth is not only a guess, but a trivial pursuit.</p>