Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
09-05-2014, 04:59 AM   #1
Forum Member




Join Date: Mar 2013
Posts: 58
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
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 47,395
QuoteOriginally posted by littlemoose Quote
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, buy your photo gear from our affiliates, Adorama, B&H Photo, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

09-05-2014, 06:38 AM   #3
Pentaxian
zman's Avatar

Join Date: Sep 2009
Location: Western NY
Photos: Albums
Posts: 489
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
Pentaxian
Site Supporter
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 30,249
QuoteOriginally posted by zman Quote
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
Pentaxian
reeftool's Avatar

Join Date: Dec 2007
Location: Upstate New York
Photos: Gallery | Albums
Posts: 8,397
QuoteOriginally posted by zman Quote
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
Site Supporter
Site Supporter




Join Date: Jun 2008
Location: Stratford, CT
Photos: Gallery
Posts: 677
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
Pentaxian
Heie's Avatar

Join Date: Nov 2011
Photos: Gallery | Albums
Posts: 968
QuoteOriginally posted by DennisH Quote
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
Pentaxian
zman's Avatar

Join Date: Sep 2009
Location: Western NY
Photos: Albums
Posts: 489
QuoteOriginally posted by reeftool Quote
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.

09-06-2014, 05:08 PM   #9
Forum Member




Join Date: Mar 2013
Posts: 58
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.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
k-mount, lens, pentax lens, quality, sigma, sigma 17-70 lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: Sigma 17-70, Tamron 70-200, Sigma 50mm 2.8 Macro, 40mm XS Lurch Sold Items 9 06-04-2014 08:59 PM
Wanna help me spend my budget? Would you buy a lens on preorder? Sigma 17-50 vs 17-70 haycyn Pentax SLR Lens Discussion 8 05-22-2013 09:15 AM
Sigma 17-70 > sigma 24-70 2.8 hsm slip Pentax SLR Lens Discussion 5 01-23-2013 11:45 AM
Want to buy: sigma 17-70 DC or Sigma 17-70 HSM raider Pentax SLR Lens Discussion 4 09-17-2011 03:24 PM
Best startre lens Pentax 17-70 or Sigma 17-70 or? mba1971 Pentax SLR Lens Discussion 14 11-02-2009 11:34 AM



All times are GMT -7. The time now is 09:56 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top