Sigma or Tamron all around lens (picture quality)

**Ahab** · 09-27-2013, 11:40 AM

I started out with the Sigma 17-50 and quickly sent it back in exchange for the Tamron 17-50. The Sigma zoom seemed sloppy and did not feel right, the images it produced were not as good as from my old Pentax ver.1 18-55. The Tammy pretty much stays on my K5 and I couldn't be happier with it.

Homo_erectus · 09-27-2013, 11:59 AM

Another consideration is that the 18-135 has fast, accurate and quiet auto-focusing while the Tamron is a screw drive so it will be louder and all of my Tamron lenses hunt a lot more than my Pentax lenses. The Sigma has an HSM focusing motor so it will be quiet and fast. My experience with Sigma lenses has been that they tend to hunt a lot, especially in low light conditions.

I have not used either of the specific Tamron or Sigma lenses mentioned in this thread however.

Mr Spocko · 10-02-2013, 10:47 AM

I suggest the Tamron 17-50mm it packs a big punch (outperforms the Pentax 16-50mm f2.8 on optics) Ok screw drive (but no SDM failures either), not as nice build and not WR but the optics count for a lot IMO.
I've used all the Sigma 17-70mm's from the first one to the most recent one it's a good lens, but drops from f2.8 quickly and you're down to f4 tele end. It is good and does a very decent macro for a zoom lens, most recent version isn't quite as good at the wide end though. The Sigma 17-50mm isn't bad either in lens AF motor, but the Tammie edges it out with better edge performance and wide open.
17-70mm is a nice range, but the f2.8 is the killer punch here so I think that is why I suggest the Tamron. If you might be in a low light situation the extra lens speed makes a big difference.

I like the Sigma, but not as much as the Tamron

Depends on what you want the 17-50/70mm lenses are an entirely different lens to the 18-135mm (I'm not fan of that lens) but some own both

seventysixersfan · 10-02-2013, 08:09 PM

really helpful feedback and comparison, thanks Mr. Spocko!!

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09-27-2013, 11:40 AM	#16
Ahab Site Supporter Join Date: Jul 2007 Location: Arnold, Md. Photos: Gallery \| Albums Posts: 762	I started out with the Sigma 17-50 and quickly sent it back in exchange for the Tamron 17-50. The Sigma zoom seemed sloppy and did not feel right, the images it produced were not as good as from my old Pentax ver.1 18-55. The Tammy pretty much stays on my K5 and I couldn't be happier with it.

09-27-2013, 11:59 AM	#17
Homo_erectus Veteran Member Join Date: Sep 2012 Posts: 410	Another consideration is that the 18-135 has fast, accurate and quiet auto-focusing while the Tamron is a screw drive so it will be louder and all of my Tamron lenses hunt a lot more than my Pentax lenses. The Sigma has an HSM focusing motor so it will be quiet and fast. My experience with Sigma lenses has been that they tend to hunt a lot, especially in low light conditions. I have not used either of the specific Tamron or Sigma lenses mentioned in this thread however.

10-02-2013, 10:47 AM	#18
Mr Spocko Senior Member Join Date: Dec 2011 Posts: 254	I suggest the Tamron 17-50mm it packs a big punch (outperforms the Pentax 16-50mm f2.8 on optics) Ok screw drive (but no SDM failures either), not as nice build and not WR but the optics count for a lot IMO. I've used all the Sigma 17-70mm's from the first one to the most recent one it's a good lens, but drops from f2.8 quickly and you're down to f4 tele end. It is good and does a very decent macro for a zoom lens, most recent version isn't quite as good at the wide end though. The Sigma 17-50mm isn't bad either in lens AF motor, but the Tammie edges it out with better edge performance and wide open. 17-70mm is a nice range, but the f2.8 is the killer punch here so I think that is why I suggest the Tamron. If you might be in a low light situation the extra lens speed makes a big difference. I like the Sigma, but not as much as the Tamron Depends on what you want the 17-50/70mm lenses are an entirely different lens to the 18-135mm (I'm not fan of that lens) but some own both

10-02-2013, 08:09 PM	#19
seventysixersfan Pentaxian Join Date: Aug 2010 Location: Alexandria, VA Posts: 2,054	really helpful feedback and comparison, thanks Mr. Spocko!!