Sigma 17-50 or 17-70 - Which would you choose

tonksj · 06-22-2018, 06:11 AM

Hi everyone
I have just upgraded from a K10D to a K3 and am thinking of getting some better quality glass for the new toy. I currently have a Sigma 18-125 which is a very useful range but sometimes I think images could be sharper.

So after reading the reviews here it appears both are well regarded lens, so I am torn between a perception of higher IQ with the 17-50 f2.8 EX or the versatility of the 17-70 f2.8

I would really be interested in hearing from anyone who has experience of both of these lenses.

How does the 17-50 f2.8-4.5 compare to the constant f2.8 EX version. It is significantly cheaper but I want an uplift in image quality so price is not necessarily going to be the deciding factor

Thanks in advance
John

panonski · 06-22-2018, 06:31 AM

I have both

---------- Post added 06-22-18 at 06:41 AM ----------

Sigma 17-70 is not constant apperture. It's 2.8- 4
and 17-50 is 2.8

Both lens are very sharp. 17-50 2.8 is more vivid, and picture is very sharp, with good bokeh. 17-70 mm is on my K3 all the time.

For pro work are both good, but with 17-50 mm you should get more specially in bokeh . 2.8 versus 4.0 is significant in space like smaller room or similar...

--
I rarely used my 17-50 mm. Because I have 17-70 which is great for all kind of photography, because 20 mm extra on long end is very usefull at concerts, and crowd.

--

For real pro work, when you would naturally use some of primes, 17-50 with constant and very good f 2.8 you can manage real good things. Some of guys claim that 17-50 mm 2.8 is like a bunch of primes inside one zoom , which is rare. Primes always have best optics, because of non -movable glass inside.

So, the label "like a bunch of primes " means a lot

**ToddK** · 06-22-2018, 06:59 AM

I have the current Sigma 17-70 Contemporary model and it is actually f2.8-4.0. It is a very nice lens but since I don't have the 17-50 I will defer to panonski for a comparison. My only drawback is the lack of weather sealing, which has prevented me from taking it out a few times in the past.

SSGGeezer · 06-22-2018, 07:06 AM

I have a Pentax DA 17-70 and it is a constant f4. It is for sale, the only issue is shipping would be at least 36 USD to you. If you can find a good one the Pentax version is better than the reviews here say. The SDM issues brought the average way down.

Last edited by SSGGeezer; 06-22-2018 at 08:07 AM.

steve_k · 06-22-2018, 07:15 AM - **1 Like**

The Pentax 16-85 is also a very nice lens and WR also.

panonski · 06-22-2018, 09:06 AM

Originally posted by ToddK

I have the current Sigma 17-70 Contemporary model and it is actually f2.8-4.0

yes, I correct that

Funny how I forgot that already

jddwoods · 06-22-2018, 10:22 AM - **1 Like**

I cannot comment on the Sigma lenses but I posed this similar question about a year ago when the SDM on my DA 17-70 died and I decided to get a replacement lens rather than repair the DA 17-70. The overwhelming response I received was in favor of the HD DA 16-85 and I bought one used in like new condition for much less than either the Sigma 18-50 f2.8 or the 17-70 contemporary would have cost. After having it for a year, I am very happy with the 16-85 and highly recommend it. It is very sharp, has a good zoom range and solid build and is WR. My only complaint and it is a minor one is that it is heavy but I think the Sigma 18-50 is even larger. I have found the range from 16-85 to be more useful compared to 17-70 than the numbers would indicate. The advantage of the Sigma lenses are they are faster, the Pentax is WR which to me was a bigger advantage.

ChristianRock · 06-22-2018, 12:12 PM - **1 Like**

My opinion: If you are looking for a Sigma 17-70mm, I would go with the latest version (f2.8-4 Contemporary) and ignore the two older versions. The oldest version (f2.8-4.5) actually isn't so bad, but at 70mm it doesn't perform all that well. The intermediate version (f/2.8-4 HSM with optical image stabilization) is better but the image stabilization system stays on even if you're not using the lens IS, because otherwise the optical element would stay lose inside the lens and the optics would not work well. And it depletes the battery faster even though it isn't used. So the latest Pentax version is not stabilized (because Pentax bodies are stabilized) and is the best one yet at 70mm wide open where it is sharp and still has beautiful contrast and colors - so it actually doubles as a very nice portrait lens. I've seen it do some lovely portraits! I feel the earlier versions lose too much sharpness and contrast at 70mm f/4 (or f/4.5).There is a reason why the Sigma 17-70 f/2.8-4 HSM Contemporary costs at least 100 dollars more in the used market than the Sigma 17-50 f/2.8 - people who have it love it and are very unlikely to sell it.

I would love to buy one, but I feel my Pentax DA 16-45mm is better in the wide end, and of course it is a bit wider there, so I can't bring myself to replace it with anything that is currently available in the market for APS-C. Also, the Pentax lens is super cheap in the used market and has the Pentax colors and rendering that I love... but I also think the new SIgma 17-70 is a fantastic lens.

seventysixersfan · 06-22-2018, 02:13 PM

Take a look at these threads:
Thoughts or opinions. Sigma 17-50 or Sigma 17-70mm - PentaxForums.com

https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/339695-sig...w-believe.html

https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/272450-sig...-50-2-8-a.html

https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/233618-dec...temporary.html

tonksj · 06-23-2018, 02:17 AM

Thanks for the responses.
As I like to do landscapes, I am perhaps leaning towards the 17-50 after reading all of your comments. I do have the 18-125 for more walk around situations so I think the combination of these 2 lenses would give the quality in the landscapes and the versatility in the every day.

Steve_k - thanks for the 16-85 suggestion, the WR is appealing but the cost of a new version in Aus is over $900 which I can't justify. Will keep a look out for a good pre-loved version though.

seventysixersfan - thanks for those links, this topic had a fair bit of discussion over the years

So all I have to now is keep an eye out on all the usual locations for the best buy.

Thanks again, John

panonski · 06-23-2018, 02:22 AM

Originally posted by tonksj

Thanks for the responses.
As I like to do landscapes, I am perhaps leaning towards the 17-50 after reading all of your comments. I do have the 18-125 for more walk around situations so I think the combination of these 2 lenses would give the quality in the landscapes and the versatility in the every day.

Steve_k - thanks for the 16-85 suggestion, the WR is appealing but the cost of a new version in Aus is over $900 which I can't justify. Will keep a look out for a good pre-loved version though.

seventysixersfan - thanks for those links, this topic had a fair bit of discussion over the years

So all I have to now is keep an eye out on all the usual locations for the best buy.

Thanks again, John

about versatility.

Sigma 17-50 mm is heavy and big lens. You could be surprised when you mounted it on

But quality of the picture justify that

tonksj · 06-24-2018, 04:30 AM

Originally posted by panonski

about versatility.

Sigma 17-50 mm is heavy and big lens. You could be surprised when you mounted it on

But quality of the picture justify that

Your are right about that, thanks for pointing it out. Looking at the weight specs, it is about 200g heavier than my 18-125. Starting to think maybe I should keep an eye out for 2nd hand Pentax 16-85

**Scorpio71GR** · 06-25-2018, 03:08 PM

Originally posted by tonksj

Your are right about that, thanks for pointing it out. Looking at the weight specs, it is about 200g heavier than my 18-125. Starting to think maybe I should keep an eye out for 2nd hand Pentax 16-85

The 16-85 is no lightweight either, especially with a 72mm front filter ring.

SSGGeezer · 06-25-2018, 03:43 PM

Originally posted by tonksj

Your are right about that, thanks for pointing it out. Looking at the weight specs, it is about 200g heavier than my 18-125. Starting to think maybe I should keep an eye out for 2nd hand Pentax 16-85

Lot more cash than some of the other options, even used.

reeftool · 06-25-2018, 06:00 PM

While I don't have Sigma's 17-50, the 17-70C is my go to lens for just about everything. I've shot 7 weddings with it and trust it to give me excellent results. I dropped it a year ago and considered the 17-50 because it was on sale for a very good price but the fine service dept. at Sigma fixed it for under $200 and I'm happily shooting with it once again.

06-22-2018, 06:11 AM	#1
tonksj Junior Member Join Date: Jan 2013 Posts: 35	Sigma 17-50 or 17-70 - Which would you choose Hi everyone I have just upgraded from a K10D to a K3 and am thinking of getting some better quality glass for the new toy. I currently have a Sigma 18-125 which is a very useful range but sometimes I think images could be sharper. So after reading the reviews here it appears both are well regarded lens, so I am torn between a perception of higher IQ with the 17-50 f2.8 EX or the versatility of the 17-70 f2.8 I would really be interested in hearing from anyone who has experience of both of these lenses. How does the 17-50 f2.8-4.5 compare to the constant f2.8 EX version. It is significantly cheaper but I want an uplift in image quality so price is not necessarily going to be the deciding factor Thanks in advance John

06-22-2018, 06:31 AM	#2
panonski Pentaxian Join Date: May 2015 Location: Zagreb Photos: Gallery \| Albums Posts: 624	I have both ---------- Post added 06-22-18 at 06:41 AM ---------- Sigma 17-70 is not constant apperture. It's 2.8- 4 and 17-50 is 2.8 Both lens are very sharp. 17-50 2.8 is more vivid, and picture is very sharp, with good bokeh. 17-70 mm is on my K3 all the time. For pro work are both good, but with 17-50 mm you should get more specially in bokeh . 2.8 versus 4.0 is significant in space like smaller room or similar... -- I rarely used my 17-50 mm. Because I have 17-70 which is great for all kind of photography, because 20 mm extra on long end is very usefull at concerts, and crowd. -- For real pro work, when you would naturally use some of primes, 17-50 with constant and very good f 2.8 you can manage real good things. Some of guys claim that 17-50 mm 2.8 is like a bunch of primes inside one zoom , which is rare. Primes always have best optics, because of non -movable glass inside. So, the label "like a bunch of primes " means a lot Last edited by panonski; 06-22-2018 at 09:04 AM.

06-22-2018, 02:13 PM	#9
seventysixersfan Pentaxian Join Date: Aug 2010 Location: Alexandria, VA Posts: 2,054	Take a look at these threads: Thoughts or opinions. Sigma 17-50 or Sigma 17-70mm - PentaxForums.com https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/339695-sig...w-believe.html https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/272450-sig...-50-2-8-a.html https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/233618-dec...temporary.html Last edited by seventysixersfan; 06-22-2018 at 02:32 PM.

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06-22-2018, 06:59 AM	#3
ToddK Loyal Site Supporter Join Date: Jan 2010 Location: Texas Hill Country Photos: Gallery Posts: 11,532	I have the current Sigma 17-70 Contemporary model and it is actually f2.8-4.0. It is a very nice lens but since I don't have the 17-50 I will defer to panonski for a comparison. My only drawback is the lack of weather sealing, which has prevented me from taking it out a few times in the past.

06-22-2018, 07:06 AM	#4
SSGGeezer Veteran Member Join Date: Jun 2017 Location: Indiana, U.S. Photos: Gallery \| Albums Posts: 4,845	I have a Pentax DA 17-70 and it is a constant f4. It is for sale, the only issue is shipping would be at least 36 USD to you. If you can find a good one the Pentax version is better than the reviews here say. The SDM issues brought the average way down. Last edited by SSGGeezer; 06-22-2018 at 08:07 AM.

06-22-2018, 07:15 AM - 1 Like	#5
steve_k Site Supporter Join Date: Dec 2016 Location: Shelton, CT Photos: Albums Posts: 708	The Pentax 16-85 is also a very nice lens and WR also.

06-22-2018, 09:06 AM	#6
panonski Pentaxian Join Date: May 2015 Location: Zagreb Photos: Gallery \| Albums Posts: 624	Originally posted by ToddK I have the current Sigma 17-70 Contemporary model and it is actually f2.8-4.0 yes, I correct that Funny how I forgot that already

06-22-2018, 10:22 AM - 1 Like	#7
jddwoods Pentaxian Join Date: Nov 2012 Location: Newark, Delaware Posts: 1,035	I cannot comment on the Sigma lenses but I posed this similar question about a year ago when the SDM on my DA 17-70 died and I decided to get a replacement lens rather than repair the DA 17-70. The overwhelming response I received was in favor of the HD DA 16-85 and I bought one used in like new condition for much less than either the Sigma 18-50 f2.8 or the 17-70 contemporary would have cost. After having it for a year, I am very happy with the 16-85 and highly recommend it. It is very sharp, has a good zoom range and solid build and is WR. My only complaint and it is a minor one is that it is heavy but I think the Sigma 18-50 is even larger. I have found the range from 16-85 to be more useful compared to 17-70 than the numbers would indicate. The advantage of the Sigma lenses are they are faster, the Pentax is WR which to me was a bigger advantage.

06-22-2018, 12:12 PM - 1 Like	#8
ChristianRock Pentaxian Join Date: Jul 2013 Location: People's Republic of America Photos: Gallery \| Albums Posts: 9,910	My opinion: If you are looking for a Sigma 17-70mm, I would go with the latest version (f2.8-4 Contemporary) and ignore the two older versions. The oldest version (f2.8-4.5) actually isn't so bad, but at 70mm it doesn't perform all that well. The intermediate version (f/2.8-4 HSM with optical image stabilization) is better but the image stabilization system stays on even if you're not using the lens IS, because otherwise the optical element would stay lose inside the lens and the optics would not work well. And it depletes the battery faster even though it isn't used. So the latest Pentax version is not stabilized (because Pentax bodies are stabilized) and is the best one yet at 70mm wide open where it is sharp and still has beautiful contrast and colors - so it actually doubles as a very nice portrait lens. I've seen it do some lovely portraits! I feel the earlier versions lose too much sharpness and contrast at 70mm f/4 (or f/4.5).There is a reason why the Sigma 17-70 f/2.8-4 HSM Contemporary costs at least 100 dollars more in the used market than the Sigma 17-50 f/2.8 - people who have it love it and are very unlikely to sell it. I would love to buy one, but I feel my Pentax DA 16-45mm is better in the wide end, and of course it is a bit wider there, so I can't bring myself to replace it with anything that is currently available in the market for APS-C. Also, the Pentax lens is super cheap in the used market and has the Pentax colors and rendering that I love... but I also think the new SIgma 17-70 is a fantastic lens.

06-23-2018, 02:17 AM	#10
tonksj Junior Member Join Date: Jan 2013 Posts: 35 Original Poster	Thanks for the responses. As I like to do landscapes, I am perhaps leaning towards the 17-50 after reading all of your comments. I do have the 18-125 for more walk around situations so I think the combination of these 2 lenses would give the quality in the landscapes and the versatility in the every day. Steve_k - thanks for the 16-85 suggestion, the WR is appealing but the cost of a new version in Aus is over $900 which I can't justify. Will keep a look out for a good pre-loved version though. seventysixersfan - thanks for those links, this topic had a fair bit of discussion over the years So all I have to now is keep an eye out on all the usual locations for the best buy. Thanks again, John

06-23-2018, 02:22 AM	#11
panonski Pentaxian Join Date: May 2015 Location: Zagreb Photos: Gallery \| Albums Posts: 624	Originally posted by tonksj Thanks for the responses. As I like to do landscapes, I am perhaps leaning towards the 17-50 after reading all of your comments. I do have the 18-125 for more walk around situations so I think the combination of these 2 lenses would give the quality in the landscapes and the versatility in the every day. Steve_k - thanks for the 16-85 suggestion, the WR is appealing but the cost of a new version in Aus is over $900 which I can't justify. Will keep a look out for a good pre-loved version though. seventysixersfan - thanks for those links, this topic had a fair bit of discussion over the years So all I have to now is keep an eye out on all the usual locations for the best buy. Thanks again, John about versatility. Sigma 17-50 mm is heavy and big lens. You could be surprised when you mounted it on But quality of the picture justify that

06-24-2018, 04:30 AM	#12
tonksj Junior Member Join Date: Jan 2013 Posts: 35 Original Poster	Originally posted by panonski about versatility. Sigma 17-50 mm is heavy and big lens. You could be surprised when you mounted it on But quality of the picture justify that Your are right about that, thanks for pointing it out. Looking at the weight specs, it is about 200g heavier than my 18-125. Starting to think maybe I should keep an eye out for 2nd hand Pentax 16-85

06-25-2018, 03:08 PM	#13
Scorpio71GR Loyal Site Supporter Join Date: Nov 2014 Location: Michigan Photos: Gallery \| Albums Posts: 6,005	Originally posted by tonksj Your are right about that, thanks for pointing it out. Looking at the weight specs, it is about 200g heavier than my 18-125. Starting to think maybe I should keep an eye out for 2nd hand Pentax 16-85 The 16-85 is no lightweight either, especially with a 72mm front filter ring.

06-25-2018, 03:43 PM	#14
SSGGeezer Veteran Member Join Date: Jun 2017 Location: Indiana, U.S. Photos: Gallery \| Albums Posts: 4,845	Originally posted by tonksj Your are right about that, thanks for pointing it out. Looking at the weight specs, it is about 200g heavier than my 18-125. Starting to think maybe I should keep an eye out for 2nd hand Pentax 16-85 Lot more cash than some of the other options, even used.

06-25-2018, 06:00 PM	#15
reeftool Pentaxian Join Date: Dec 2007 Location: Upstate New York Photos: Gallery \| Albums Posts: 9,554	While I don't have Sigma's 17-50, the 17-70C is my go to lens for just about everything. I've shot 7 weddings with it and trust it to give me excellent results. I dropped it a year ago and considered the 17-50 because it was on sale for a very good price but the fine service dept. at Sigma fixed it for under $200 and I'm happily shooting with it once again.