Sigma 17-70 vs Pentax 18-135?


jamkid

Member
Nov 30, 2010
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Hi all,
I'm looking for a new lens to replace my kit lens (18-55).
Has come down to either the sigma 17-70 or the pentax 18-135 since both in the same price range.
Sigma for the speed and pentax for the extra reach.
Will the sigma be sharper?
Any comments between the two?
I mainly shoot streets btw.
Thanks in advance for the feedbacks.
 

Hi all,
I'm looking for a new lens to replace my kit lens (18-55).
Has come down to either the sigma 17-70 or the pentax 18-135 since both in the same price range.
Sigma for the speed and pentax for the extra reach.
Will the sigma be sharper?
Any comments between the two?
I mainly shoot streets btw.
Thanks in advance for the feedbacks.

For street use, its always better to have longer zoom for that more discrete shot. And the coverage of the 18-135 is definitely more usable. :)
 

thanks for the input.
I think i'll go for the pentax then...
the extra reach is a bigger draw to me over the wider aperture, but seems like cant get the best of both world with my budget.
the image quality between the two should be too far off right?
of coz i undertand longer zoom should suffer a bit more in terms of quality.
 

i tried both and i chose the DA 18-135.

Focus motor: The DC motor feels slightly faster than HSM.

Aperture range: The 17-70 is f2.8 at 17mm, while the 18-135 is f3.5 at 18mm. A small difference. At 70mm, the 17-70 is f4(or 4.5 depending on the version you get), while the 18-135 gives you f4.5 at 68mm. The two are pretty even in this aspect in terms of speed. However, of course, the 18-135 is much better from 70-135mm:bsmilie:

Bokeh: I prefered the bokeh of the 18-135. Not very much below 70mm, but you do get versatility in bokeh-playing when you extend the range beyond 70mm.

Sharpness: Both are equally sharp, when viewed at 100%. The sigma turned out just a bit sharper at 100% for a couple of photos, but not sufficiently to differentiate the two.

IQ: The IQ of both lenses are really good. I doubt you can go wrong with either. For the 18-135 you can view some sample shots here. http://www.pentaxforums.com/forums/...8-135mm-full-length-review-6.html#post1293146

Build quality wise: the 18-135 win hands down.

Weather resistance: Ditto

Hope this helps. Nevertheless, it will be good if you could try out both copies, to see which suits you better.;)
 

Havent tried any but i think i would go for the 18-135 as it is more versitile, unless you are into night photography i think more range would be better than speed, then again the 18-135 costs i think almost twice as much so then again budget may be of concern
 

i tried both and i chose the DA 18-135.

Focus motor: The DC motor feels slightly faster than HSM.

Aperture range: The 17-70 is f2.8 at 17mm, while the 18-135 is f3.5 at 18mm. A small difference. At 70mm, the 17-70 is f4(or 4.5 depending on the version you get), while the 18-135 gives you f4.5 at 68mm. The two are pretty even in this aspect in terms of speed. However, of course, the 18-135 is much better from 70-135mm:bsmilie:

Bokeh: I prefered the bokeh of the 18-135. Not very much below 70mm, but you do get versatility in bokeh-playing when you extend the range beyond 70mm.

Sharpness: Both are equally sharp, when viewed at 100%. The sigma turned out just a bit sharper at 100% for a couple of photos, but not sufficiently to differentiate the two.

IQ: The IQ of both lenses are really good. I doubt you can go wrong with either. For the 18-135 you can view some sample shots here. http://www.pentaxforums.com/forums/...8-135mm-full-length-review-6.html#post1293146

Build quality wise: the 18-135 win hands down.

Weather resistance: Ditto

Hope this helps. Nevertheless, it will be good if you could try out both copies, to see which suits you better.;)

great info!
will be heading down to get the pentax soon as a boxing day present so i'll have something to unbox :bsmilie:

thanks for the inputs!
 

i tried both and i chose the DA 18-135.

Focus motor: The DC motor feels slightly faster than HSM.

Aperture range: The 17-70 is f2.8 at 17mm, while the 18-135 is f3.5 at 18mm. A small difference. At 70mm, the 17-70 is f4(or 4.5 depending on the version you get), while the 18-135 gives you f4.5 at 68mm. The two are pretty even in this aspect in terms of speed. However, of course, the 18-135 is much better from 70-135mm:bsmilie:

Bokeh: I prefered the bokeh of the 18-135. Not very much below 70mm, but you do get versatility in bokeh-playing when you extend the range beyond 70mm.

Sharpness: Both are equally sharp, when viewed at 100%. The sigma turned out just a bit sharper at 100% for a couple of photos, but not sufficiently to differentiate the two.

IQ: The IQ of both lenses are really good. I doubt you can go wrong with either. For the 18-135 you can view some sample shots here. http://www.pentaxforums.com/forums/...8-135mm-full-length-review-6.html#post1293146

Build quality wise: the 18-135 win hands down.

Weather resistance: Ditto

Hope this helps. Nevertheless, it will be good if you could try out both copies, to see which suits you better.;)

Nice sum up :thumbsup: I'd also go w/ DA18-135 if choosing between these two :)
 

I think even with the da 17-70mm f4 is in , the da 18-135mm still win my vote
 

I've got my 18-135 yesterday.
Haven't really use it for street yet, but have shoot a number of shots of my friend's daughter with good results with my beginner's skill.
So far am really happy with this purchase.
Thanks for all the inputs especially @ohyouloveme for the breakdown.
cheers
 

how much u bought the 18-135mm? bought direct from emjay? thanks

not sure abt the forum rule of posting prices.
anyway i got mine from slr, the lowest price among those i checked. :)
Can give them a call to check.
over the phone they may not sound that friendly, but at the shop the staffs are. :)
 

Oh focusing speed of sigma 1770 screwdrive is already impressive on k7, if can see big difference on 18135,then it's really worth to take... :thumbsup: