Sigma 17-70 lens advice

littlemoose · 09-05-2014, 04:59 AM

I currently use my Kx with a Sigma 18-200 DC and sometimes I think the optical quality is not great . I can acquire a Sigma 17-70 at a very good price. The tests of the 17-70 indicate that it is a sharper lens than the 18-200. Does anyone have experience on whether or not image quality will noticeably improve?
Thanks

Adam · 09-05-2014, 06:28 AM

Originally posted by littlemoose

I currently use my Kx with a Sigma 18-200 DC and sometimes I think the optical quality is not great . I can acquire a Sigma 17-70 at a very good price. The tests of the 17-70 indicate that it is a sharper lens than the 18-200. Does anyone have experience on whether or not image quality will noticeably improve?
Thanks

Yes, you should see a huge jump in image quality. Superzoom lenses are always a compromise.

zman · 09-05-2014, 06:38 AM

I use the Sigma 17-70mm C lens frequently. It does produce sharp images, will give you good close-up shots, and its focal ranges fit my needs well. Its auto focus is fast and near silent. The only weird thing, at least for me, is that the zoom ring rotates in the opposite direction of my other lenses.

normhead · 09-05-2014, 06:51 AM

Originally posted by zman

I use the Sigma 17-70mm C lens frequently. It does produce sharp images, will give you good close-up shots, and its focal ranges fit my needs well. Its auto focus is fast and near silent. The only weird thing, at least for me, is that the zoom ring rotates in the opposite direction of my other lenses.

If he has the Sigma 18-200, he's used to it.

reeftool · 09-05-2014, 07:36 AM

Originally posted by zman

I use the Sigma 17-70mm C lens frequently. It does produce sharp images, will give you good close-up shots, and its focal ranges fit my needs well. Its auto focus is fast and near silent. The only weird thing, at least for me, is that the zoom ring rotates in the opposite direction of my other lenses.

I also have the Sigma 17-70C. It's a very good walk around lens. The zoom ring is the same on all Sigma lenses and the opposite of everybody else. I currently own 4 zooms, two Sigma and two Pentax. The 17-70 pretty much replaced my kit lens and my DA 10-17 isn't an everyday lens so I'm quite used to the Sigma zoom operation.

DennisH · 09-05-2014, 07:59 AM

I'm also interested in this lens. What is the max aperture at various focal lengths, particularly between 20 and 35mm?

Heie · 09-05-2014, 10:39 AM

Originally posted by DennisH

I'm also interested in this lens. What is the max aperture at various focal lengths, particularly between 20 and 35mm?

This may help. This lens (17-70 C) was the key comparison against the DA 18-135 WR in the most recent in-depth review. In it was a variable aperture range chart that you may find of benefit comparing the two lenses (and the DA 18-55). The below was taken from that review:

It's been mentioned that this is a variable aperture zoom lens. In order to make it easier to visually grasp the exact aperture range of this lens, namely where each maximum and minimum aperture lies along the entirety of the focal length range, we've created the following diagram for you. Above the axis lie the maximum apertures, with the minimum possible openings underneath.

In addition to the DA 18-135 WR and the DA 18-55, we included the latest incarnation of Sigma's 17-70 as well so you can see how its variable aperture range compares.
We were quite astonished to realize that with the 18-135, you lose only 1/3 of a stop for the majority of the zoom range, with the greatest variance being 2/3 stop between 28mm and 45mm. Compared to the much heavier and larger-front-element-wielding 17-70, we expected a larger difference between the two, especially considering how that with the 18-135 WR, you get not only weather sealing, but an additional 65mm of optical zoom.

Regarding the zooming of the lens, the 17-70 C is opposite that of Pentax lenses (which start with the lower focal length on the right side when looking at them top-down). This .gif (also from that review) should make that clear:

Hopefully this helps, and if you wish to view that review, that's substantial comparisons between these two lenses, especially with sharpness and bokeh. To visit that in-depth review, click here.

-Heie

Last edited by Heie; 09-05-2014 at 11:00 AM.

zman · 09-05-2014, 10:43 AM

Originally posted by reeftool

I also have the Sigma 17-70C. It's a very good walk around lens. The zoom ring is the same on all Sigma lenses and the opposite of everybody else. I currently own 4 zooms, two Sigma and two Pentax. The 17-70 pretty much replaced my kit lens and my DA 10-17 isn't an everyday lens so I'm quite used to the Sigma zoom operation.

I thought I was confused about the 17-70 C zoom ring, so I brought out my other two Sigma zooms (10-20, 70-200). On the 17-70 C I have to rotate the zoom ring counter-clockwise to zoom in on my subject. On my other Sigma's I have to rotate the ring clockwise to zoom in.

littlemoose · 09-06-2014, 05:08 PM

Thanks to all those who replied. Reassuring that improvement is likely.

I have placed my order and in a week or so I will know.

09-05-2014, 04:59 AM	#1
littlemoose Forum Member Join Date: Mar 2013 Location: Brisbane Posts: 88	Sigma 17-70 lens advice I currently use my Kx with a Sigma 18-200 DC and sometimes I think the optical quality is not great . I can acquire a Sigma 17-70 at a very good price. The tests of the 17-70 indicate that it is a sharper lens than the 18-200. Does anyone have experience on whether or not image quality will noticeably improve? Thanks

09-05-2014, 06:28 AM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,608	Originally posted by littlemoose I currently use my Kx with a Sigma 18-200 DC and sometimes I think the optical quality is not great . I can acquire a Sigma 17-70 at a very good price. The tests of the 17-70 indicate that it is a sharper lens than the 18-200. Does anyone have experience on whether or not image quality will noticeably improve? Thanks Yes, you should see a huge jump in image quality. Superzoom lenses are always a compromise. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

09-06-2014, 05:08 PM	#9
littlemoose Forum Member Join Date: Mar 2013 Location: Brisbane Posts: 88 Original Poster	Is Sigma 17-70mm f2.8-4 an upgrade Thanks to all those who replied. Reassuring that improvement is likely. I have placed my order and in a week or so I will know.

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09-05-2014, 06:38 AM	#3
zman Pentaxian Join Date: Sep 2009 Location: Western NY Photos: Albums Posts: 515	I use the Sigma 17-70mm C lens frequently. It does produce sharp images, will give you good close-up shots, and its focal ranges fit my needs well. Its auto focus is fast and near silent. The only weird thing, at least for me, is that the zoom ring rotates in the opposite direction of my other lenses.

09-05-2014, 06:51 AM	#4
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	Originally posted by zman I use the Sigma 17-70mm C lens frequently. It does produce sharp images, will give you good close-up shots, and its focal ranges fit my needs well. Its auto focus is fast and near silent. The only weird thing, at least for me, is that the zoom ring rotates in the opposite direction of my other lenses. If he has the Sigma 18-200, he's used to it.

09-05-2014, 07:36 AM	#5
reeftool Pentaxian Join Date: Dec 2007 Location: Upstate New York Photos: Gallery \| Albums Posts: 9,555	Originally posted by zman I use the Sigma 17-70mm C lens frequently. It does produce sharp images, will give you good close-up shots, and its focal ranges fit my needs well. Its auto focus is fast and near silent. The only weird thing, at least for me, is that the zoom ring rotates in the opposite direction of my other lenses. I also have the Sigma 17-70C. It's a very good walk around lens. The zoom ring is the same on all Sigma lenses and the opposite of everybody else. I currently own 4 zooms, two Sigma and two Pentax. The 17-70 pretty much replaced my kit lens and my DA 10-17 isn't an everyday lens so I'm quite used to the Sigma zoom operation.

09-05-2014, 07:59 AM	#6
DennisH Pentaxian Join Date: Jun 2008 Location: Stratford, CT Photos: Gallery Posts: 730	I'm also interested in this lens. What is the max aperture at various focal lengths, particularly between 20 and 35mm?

09-05-2014, 10:39 AM	#7
Heie Veteran Member Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 968	Originally posted by DennisH I'm also interested in this lens. What is the max aperture at various focal lengths, particularly between 20 and 35mm? This may help. This lens (17-70 C) was the key comparison against the DA 18-135 WR in the most recent in-depth review. In it was a variable aperture range chart that you may find of benefit comparing the two lenses (and the DA 18-55). The below was taken from that review: It's been mentioned that this is a variable aperture zoom lens. In order to make it easier to visually grasp the exact aperture range of this lens, namely where each maximum and minimum aperture lies along the entirety of the focal length range, we've created the following diagram for you. Above the axis lie the maximum apertures, with the minimum possible openings underneath. In addition to the DA 18-135 WR and the DA 18-55, we included the latest incarnation of Sigma's 17-70 as well so you can see how its variable aperture range compares. We were quite astonished to realize that with the 18-135, you lose only 1/3 of a stop for the majority of the zoom range, with the greatest variance being 2/3 stop between 28mm and 45mm. Compared to the much heavier and larger-front-element-wielding 17-70, we expected a larger difference between the two, especially considering how that with the 18-135 WR, you get not only weather sealing, but an additional 65mm of optical zoom. Regarding the zooming of the lens, the 17-70 C is opposite that of Pentax lenses (which start with the lower focal length on the right side when looking at them top-down). This .gif (also from that review) should make that clear: Hopefully this helps, and if you wish to view that review, that's substantial comparisons between these two lenses, especially with sharpness and bokeh. To visit that in-depth review, click here. -Heie Last edited by Heie; 09-05-2014 at 11:00 AM.

09-05-2014, 10:43 AM	#8
zman Pentaxian Join Date: Sep 2009 Location: Western NY Photos: Albums Posts: 515	Originally posted by reeftool I also have the Sigma 17-70C. It's a very good walk around lens. The zoom ring is the same on all Sigma lenses and the opposite of everybody else. I currently own 4 zooms, two Sigma and two Pentax. The 17-70 pretty much replaced my kit lens and my DA 10-17 isn't an everyday lens so I'm quite used to the Sigma zoom operation. I thought I was confused about the 17-70 C zoom ring, so I brought out my other two Sigma zooms (10-20, 70-200). On the 17-70 C I have to rotate the zoom ring counter-clockwise to zoom in on my subject. On my other Sigma's I have to rotate the ring clockwise to zoom in.