With some sadness, goodbye DA16-85... and hello Sigma 17-50 f/2.8

**BigMackCam** · 12-01-2015, 02:24 PM

Well, I spoke to my supplier and they acknowledged the problem with the second copy of my DA16-85 (it was de-centered, with blurring in the upper right even at f/8, 50mm). After two copies, one suffering from a jumpy viewfinder image when focusing, the other with de-centering, I reluctantly decided to opt for a refund. I really, really liked the lens - but the two problems I encountered were the same two problems reported by a handful of other users (at least one of whom had the same two problems with two copies). Whilst it could be that I was just very unlucky, my supplier agreed that the chances of me being content with a third copy were probably 50/50. So there it is...

Replacing the 16-85 with another zoom was tough. I really wanted a Pentax lens (to go with my primes and the 55-300, all of which I love and have had no problems with). But, in the end, I went with the Sigma 17-50 f/2.8 "stack o' primes". It arrived today and - jittery after my 16-85 experience - I put it through its paces with focus adjustment (I settled on -2) and some casual tests. From what I've found so far, this is a cracking lens in terms of sharpness, both center and border, especially by f/4. I understand the extreme edges suffer wide open, except at 50mm, but haven't tested that - and don't really plan to, as I'm happy with what I see so far. It seems decent wide open, too, though I can immediately see the difference - even at the center - between f/2.8 and f/4 (not surprisingly). When the situation requires it, though, I'll have no worries about using it wide open. AF accuracy is good, though not quite as good as the DA16-85 in poor lighting, from what I can tell - I've had a few misses, but I'm fine with it. I do wish it had full-time manual focus over-ride like the DA16-85, but I knew this limitation when I chose it, so I can't complain. In any case, I didn't like the feel of the focus ring on the DA16-85 and found it difficult to use with any degree of speed. Conversely, MF with the Sigma is a real pleasure - unexpectedly good, in fact, considering the short throw. It's a heavy lens, and I wish it were WR... but I guess we can't have everything, eh? Overall, first impressions are very good indeed. It's no prime, but should be an excellent partner to the 55-300 as a two lens reduced kit.

I'll be honest, though - I'm sort of pining for the DA16-85...

Imp · 12-01-2015, 02:32 PM

Why Sigma 17-50 2.8 vs. Tamron 17-50 2.8?

FantasticMrFox · 12-01-2015, 02:41 PM

Originally posted by Imp

Why Sigma 17-50 2.8 vs. Tamron 17-50 2.8?

Probably better AF (HSM vs. screw drive)?

**csa** · 12-01-2015, 02:46 PM

Mike, I'm really sorry to hear this; not only for you, but for me. I was planning on getting this lens in the future, does make me pause & reconsider.

**BigMackCam** · 12-01-2015, 02:53 PM

Good question. I came very close to getting the Tammy. Reading the many reviews of both (including the three-way shoot-out between the Tammy, Sigma and Pentax 16-50 here on PentaxForums), it seemed that the Sigma just edged ahead on build quality, frame-wide sharpness at brighter apertures, and - importantly - manual focusing. Added to that, value for money - here in the UK, the cheapest deal right now on the Tammy - from a good supplier - is around £250 (roughly 375 bucks at today's exchange rate), while the Sigma is around £300 (450 bucks), but for a limited time it comes with a free Sigma EF-610 DG ST speedlight via mail-in coupon (extremely limited when it comes to manual control, but otherwise very useful). I may even sell the flash, but I suspect I'll just keep it.

When all's said and done, I'm sure I would have been happy with the Tamron, but initial impressions are good with the Sigma (time will tell, of course!

).

---------- Post added 12-01-2015 at 09:59 PM ----------

Originally posted by FantasticMrFox

Probably better AF (HSM vs. screw drive)?

You'd think so, but I've also read that the Tammy's AF can be more consistent than the Sigma. Noisier, for sure, but I'll be honest, screw drive noise just doesn't bother me for my shooting. Sigma's HSM certainly is *very* quiet, though!

**lsimpkins** · 12-01-2015, 03:02 PM

Originally posted by BigMackCam

Well, I spoke to my supplier and they acknowledged the problem with the second copy of my DA16-85 (it was de-centered, with blurring in the upper right even at f/8, 50mm). After two copies, one suffering from a jumpy viewfinder image when focusing, the other with de-centering, I reluctantly decided to opt for a refund. I really, really liked the lens - but the two problems I encountered were the same two problems reported by a handful of other users (at least one of whom had the same two problems with two copies). Whilst it could be that I was just very unlucky, my supplier agreed that the chances of me being content with a third copy were probably 50/50. So there it is...

Replacing the 16-85 with another zoom was tough. I really wanted a Pentax lens (to go with my primes and the 55-300, all of which I love and have had no problems with). But, in the end, I went with the Sigma 17-50 f/2.8 "stack o' primes". It arrived today and - jittery after my 16-85 experience - I put it through its paces with focus adjustment (I settled on -2) and some casual tests. From what I've found so far, this is a cracking lens in terms of sharpness, both center and border, especially by f/4. I understand the extreme edges suffer wide open, except at 50mm, but haven't tested that - and don't really plan to, as I'm happy with what I see so far. It seems decent wide open, too, though I can immediately see the difference - even at the center - between f/2.8 and f/4 (not surprisingly). When the situation requires it, though, I'll have no worries about using it wide open. AF accuracy is good, though not quite as good as the DA16-85 in poor lighting, from what I can tell - I've had a few misses, but I'm fine with it. I do wish it had full-time manual focus over-ride like the DA16-85, but I knew this limitation when I chose it, so I can't complain. In any case, I didn't like the feel of the focus ring on the DA16-85 and found it difficult to use with any degree of speed. Conversely, MF with the Sigma is a real pleasure - unexpectedly good, in fact, considering the short throw. It's a heavy lens, and I wish it were WR... but I guess we can't have everything, eh? Overall, first impressions are very good indeed. It's no prime, but should be an excellent partner to the 55-300 as a two lens reduced kit.

I'll be honest, though - I'm sort of pining for the DA16-85...

Mike, I heartily agree with your assessment of the Sigma. For me it was a very large step up in IQ from my original 18-55mm kit lens. I concur with all your observations regarding its performance, as well as the lament regarding the missing WR. I too have paired it with the 55-300mm zoom for a reduced kit (although I hate to leave my Pentax 12-24 home as its IQ is outstanding in my opinion.

**BigMackCam** · 12-01-2015, 03:05 PM

Originally posted by csa

Mike, I'm really sorry to hear this; not only for you, but for me. I was planning on getting this lens in the future, does make me pause & reconsider.

Thanks, Carol

I'm disappointed, really. But, do bear in mind there are plenty here who are happy with their 16-85s. So long as you go with a decent supplier (those represented on PentaxForums, for instance) with good returns policies, I don't think you have anything to worry about. Honestly, if I had ended up with a good 16-85 the second time around, I wouldn't have worried about the few reports of issues I've read. It's a nicely constructed, light, WR lens with really good sharpness (if you discount the de-centering problem I had). My Sigma is heavier, it's not WR, and it doesn't cover such a useful focal range... But for me, it'll do just fine, I think.

**csa** · 12-01-2015, 03:08 PM

Mike, thanks!

**BigMackCam** · 12-01-2015, 03:19 PM

Originally posted by lsimpkins

Mike, I heartily agree with your assessment of the Sigma. For me it was a very large step up in IQ from my original 18-55mm kit lens. I concur with all your observations regarding its performance, as well as the lament regarding the missing WR. I too have paired it with the 55-300mm zoom for a reduced kit (although I hate to leave my Pentax 12-24 home as its IQ is outstanding in my opinion.

Thanks, it's great to hear a second opinion. I just wish you hadn't mentioned the 12-24

That's a lens I'd like to own, as I have nothing at the ultra-wide end (I have the DA15 which I really like, but nothing wider)... From what I hear, it's really impressive, particularly at the wide end! <drool>

audiobomber · 12-01-2015, 05:53 PM

Originally posted by BigMackCam

You'd think so, but I've also read that the Tammy's AF can be more consistent than the Sigma. Noisier, for sure, but I'll be honest, screw drive noise just doesn't bother me for my shooting. Sigma's HSM certainly is *very* quiet, though!

I've been reading two Pentax forums daily for eight years. The Tamron 17-50 has had more AF issues than any other K-mount lens, IMO, and is also unreliable across other brands. The Sigma is much better built, quiet AF and sharper at wide apertures.

My copy needed no AF Adjust and locks focus reliably. BigMackCam, you aren't using a K-5 are you?

**BigMackCam** · 12-01-2015, 06:04 PM

Originally posted by audiobomber

I've been reading two Pentax forums daily for eight years. The Tamron 17-50 has had more AF issues than any other K-mount lens, IMO, and is also unreliable across other brands. The Sigma is much better built, quiet AF and sharper at wide apertures.

My copy needed no AF Adjust and locks focus reliably. BigMackCam, you aren't using a K-5 are you?

Thanks for that

Yes, my original tests with the lens were on my K5. My main camera is a K3, though (although I swap between them and, increasingly, don't treat them as main / backup). Haven't tried the lens on the K3 just yet...

audiobomber · 12-01-2015, 09:06 PM

Originally posted by BigMackCam

Thanks for that

Yes, my original tests with the lens were on my K5. My main camera is a K3, though (although I swap between them and, increasingly, don't treat them as main / backup). Haven't tried the lens on the K3 just yet...

Don't judge the 17-50 until you try it on the K-3. The K-3 has three f/2.8-sensitive AF sensors, the K-5 has none. That alone will make a difference. Plus the AF module is two generations beyond the K-5's.

**DDoram** · 12-02-2015, 10:03 AM

I have both the DA 16-85 which is a great lens and the Sigma 17-50 (f2.8). Both are great lenses; the Pentax is used as a general walk around outdoors while the Sigma is used for events due its constant f2.8.

**BigMackCam** · 12-02-2015, 10:07 AM

Originally posted by audiobomber

Don't judge the 17-50 until you try it on the K-3. The K-3 has three f/2.8-sensitive AF sensors, the K-5 has none. That alone will make a difference. Plus the AF module is two generations beyond the K-5's.

Don't get me wrong, it's performing great on the K5, just not quite so consistent on AF accuracy as the 16-85 - specifically, close focus (5 - 6 feet), wide open at 50mm in fairly poor light. I tried it today on the K3 and it's definitely better than on the K5 - but I think the 16-85 still has the edge on accuracy. That said, I'm delighted with the Sigma - a really nice lens considering the street price.

audiobomber · 12-02-2015, 10:10 AM

Originally posted by BigMackCam

Don't get me wrong, it's performing great on the K5, just not quite so consistent on AF accuracy as the 16-85 - specifically, close focus (5 - 6 feet), wide open at 50mm in fairly poor light. I tried it today on the K3 and it's definitely better than on the K5 - but I think the 16-85 still has the edge on accuracy. That said, I'm delighted with the Sigma - a really nice lens considering the street price.

Did you try AF Adjust with the K-3? The lens won't necessarily need the same correction on different bodies.

12-01-2015, 02:24 PM	#1
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,695	With some sadness, goodbye DA16-85... and hello Sigma 17-50 f/2.8 Well, I spoke to my supplier and they acknowledged the problem with the second copy of my DA16-85 (it was de-centered, with blurring in the upper right even at f/8, 50mm). After two copies, one suffering from a jumpy viewfinder image when focusing, the other with de-centering, I reluctantly decided to opt for a refund. I really, really liked the lens - but the two problems I encountered were the same two problems reported by a handful of other users (at least one of whom had the same two problems with two copies). Whilst it could be that I was just very unlucky, my supplier agreed that the chances of me being content with a third copy were probably 50/50. So there it is... Replacing the 16-85 with another zoom was tough. I really wanted a Pentax lens (to go with my primes and the 55-300, all of which I love and have had no problems with). But, in the end, I went with the Sigma 17-50 f/2.8 "stack o' primes". It arrived today and - jittery after my 16-85 experience - I put it through its paces with focus adjustment (I settled on -2) and some casual tests. From what I've found so far, this is a cracking lens in terms of sharpness, both center and border, especially by f/4. I understand the extreme edges suffer wide open, except at 50mm, but haven't tested that - and don't really plan to, as I'm happy with what I see so far. It seems decent wide open, too, though I can immediately see the difference - even at the center - between f/2.8 and f/4 (not surprisingly). When the situation requires it, though, I'll have no worries about using it wide open. AF accuracy is good, though not quite as good as the DA16-85 in poor lighting, from what I can tell - I've had a few misses, but I'm fine with it. I do wish it had full-time manual focus over-ride like the DA16-85, but I knew this limitation when I chose it, so I can't complain. In any case, I didn't like the feel of the focus ring on the DA16-85 and found it difficult to use with any degree of speed. Conversely, MF with the Sigma is a real pleasure - unexpectedly good, in fact, considering the short throw. It's a heavy lens, and I wish it were WR... but I guess we can't have everything, eh? Overall, first impressions are very good indeed. It's no prime, but should be an excellent partner to the 55-300 as a two lens reduced kit. I'll be honest, though - I'm sort of pining for the DA16-85...

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12-01-2015, 02:32 PM	#2
Imp Pentaxian Join Date: Nov 2014 Location: Washington, DC Photos: Gallery \| Albums Posts: 1,749	Why Sigma 17-50 2.8 vs. Tamron 17-50 2.8?

12-01-2015, 02:41 PM	#3
FantasticMrFox Veteran Member Join Date: Oct 2014 Location: Munich Posts: 2,339	Originally posted by Imp Why Sigma 17-50 2.8 vs. Tamron 17-50 2.8? Probably better AF (HSM vs. screw drive)?

12-01-2015, 02:46 PM	#4
csa Loyal Site Supporter Join Date: Aug 2014 Location: Montana mountains Posts: 10,133	Mike, I'm really sorry to hear this; not only for you, but for me. I was planning on getting this lens in the future, does make me pause & reconsider.

12-01-2015, 02:53 PM	#5
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,695 Original Poster	Good question. I came very close to getting the Tammy. Reading the many reviews of both (including the three-way shoot-out between the Tammy, Sigma and Pentax 16-50 here on PentaxForums), it seemed that the Sigma just edged ahead on build quality, frame-wide sharpness at brighter apertures, and - importantly - manual focusing. Added to that, value for money - here in the UK, the cheapest deal right now on the Tammy - from a good supplier - is around £250 (roughly 375 bucks at today's exchange rate), while the Sigma is around £300 (450 bucks), but for a limited time it comes with a free Sigma EF-610 DG ST speedlight via mail-in coupon (extremely limited when it comes to manual control, but otherwise very useful). I may even sell the flash, but I suspect I'll just keep it. When all's said and done, I'm sure I would have been happy with the Tamron, but initial impressions are good with the Sigma (time will tell, of course! ). ---------- Post added 12-01-2015 at 09:59 PM ---------- Originally posted by FantasticMrFox Probably better AF (HSM vs. screw drive)? You'd think so, but I've also read that the Tammy's AF can be more consistent than the Sigma. Noisier, for sure, but I'll be honest, screw drive noise just doesn't bother me for my shooting. Sigma's HSM certainly is very quiet, though!

12-01-2015, 03:02 PM	#6
lsimpkins Site Supporter Join Date: Feb 2013 Location: SE Pennsylvania Photos: Gallery \| Albums Posts: 544	Originally posted by BigMackCam Well, I spoke to my supplier and they acknowledged the problem with the second copy of my DA16-85 (it was de-centered, with blurring in the upper right even at f/8, 50mm). After two copies, one suffering from a jumpy viewfinder image when focusing, the other with de-centering, I reluctantly decided to opt for a refund. I really, really liked the lens - but the two problems I encountered were the same two problems reported by a handful of other users (at least one of whom had the same two problems with two copies). Whilst it could be that I was just very unlucky, my supplier agreed that the chances of me being content with a third copy were probably 50/50. So there it is... Replacing the 16-85 with another zoom was tough. I really wanted a Pentax lens (to go with my primes and the 55-300, all of which I love and have had no problems with). But, in the end, I went with the Sigma 17-50 f/2.8 "stack o' primes". It arrived today and - jittery after my 16-85 experience - I put it through its paces with focus adjustment (I settled on -2) and some casual tests. From what I've found so far, this is a cracking lens in terms of sharpness, both center and border, especially by f/4. I understand the extreme edges suffer wide open, except at 50mm, but haven't tested that - and don't really plan to, as I'm happy with what I see so far. It seems decent wide open, too, though I can immediately see the difference - even at the center - between f/2.8 and f/4 (not surprisingly). When the situation requires it, though, I'll have no worries about using it wide open. AF accuracy is good, though not quite as good as the DA16-85 in poor lighting, from what I can tell - I've had a few misses, but I'm fine with it. I do wish it had full-time manual focus over-ride like the DA16-85, but I knew this limitation when I chose it, so I can't complain. In any case, I didn't like the feel of the focus ring on the DA16-85 and found it difficult to use with any degree of speed. Conversely, MF with the Sigma is a real pleasure - unexpectedly good, in fact, considering the short throw. It's a heavy lens, and I wish it were WR... but I guess we can't have everything, eh? Overall, first impressions are very good indeed. It's no prime, but should be an excellent partner to the 55-300 as a two lens reduced kit. I'll be honest, though - I'm sort of pining for the DA16-85... Mike, I heartily agree with your assessment of the Sigma. For me it was a very large step up in IQ from my original 18-55mm kit lens. I concur with all your observations regarding its performance, as well as the lament regarding the missing WR. I too have paired it with the 55-300mm zoom for a reduced kit (although I hate to leave my Pentax 12-24 home as its IQ is outstanding in my opinion.

12-01-2015, 03:05 PM	#7
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,695 Original Poster	Originally posted by csa Mike, I'm really sorry to hear this; not only for you, but for me. I was planning on getting this lens in the future, does make me pause & reconsider. Thanks, Carol I'm disappointed, really. But, do bear in mind there are plenty here who are happy with their 16-85s. So long as you go with a decent supplier (those represented on PentaxForums, for instance) with good returns policies, I don't think you have anything to worry about. Honestly, if I had ended up with a good 16-85 the second time around, I wouldn't have worried about the few reports of issues I've read. It's a nicely constructed, light, WR lens with really good sharpness (if you discount the de-centering problem I had). My Sigma is heavier, it's not WR, and it doesn't cover such a useful focal range... But for me, it'll do just fine, I think.

12-01-2015, 03:08 PM	#8
csa Loyal Site Supporter Join Date: Aug 2014 Location: Montana mountains Posts: 10,133	Mike, thanks!

12-01-2015, 03:19 PM	#9
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,695 Original Poster	Originally posted by lsimpkins Mike, I heartily agree with your assessment of the Sigma. For me it was a very large step up in IQ from my original 18-55mm kit lens. I concur with all your observations regarding its performance, as well as the lament regarding the missing WR. I too have paired it with the 55-300mm zoom for a reduced kit (although I hate to leave my Pentax 12-24 home as its IQ is outstanding in my opinion. Thanks, it's great to hear a second opinion. I just wish you hadn't mentioned the 12-24 That's a lens I'd like to own, as I have nothing at the ultra-wide end (I have the DA15 which I really like, but nothing wider)... From what I hear, it's really impressive, particularly at the wide end! <drool>

12-01-2015, 05:53 PM	#10
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	Originally posted by BigMackCam You'd think so, but I've also read that the Tammy's AF can be more consistent than the Sigma. Noisier, for sure, but I'll be honest, screw drive noise just doesn't bother me for my shooting. Sigma's HSM certainly is very quiet, though! I've been reading two Pentax forums daily for eight years. The Tamron 17-50 has had more AF issues than any other K-mount lens, IMO, and is also unreliable across other brands. The Sigma is much better built, quiet AF and sharper at wide apertures. My copy needed no AF Adjust and locks focus reliably. BigMackCam, you aren't using a K-5 are you?

12-01-2015, 06:04 PM	#11
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,695 Original Poster	Originally posted by audiobomber I've been reading two Pentax forums daily for eight years. The Tamron 17-50 has had more AF issues than any other K-mount lens, IMO, and is also unreliable across other brands. The Sigma is much better built, quiet AF and sharper at wide apertures. My copy needed no AF Adjust and locks focus reliably. BigMackCam, you aren't using a K-5 are you? Thanks for that Yes, my original tests with the lens were on my K5. My main camera is a K3, though (although I swap between them and, increasingly, don't treat them as main / backup). Haven't tried the lens on the K3 just yet...

12-01-2015, 09:06 PM	#12
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	Originally posted by BigMackCam Thanks for that Yes, my original tests with the lens were on my K5. My main camera is a K3, though (although I swap between them and, increasingly, don't treat them as main / backup). Haven't tried the lens on the K3 just yet... Don't judge the 17-50 until you try it on the K-3. The K-3 has three f/2.8-sensitive AF sensors, the K-5 has none. That alone will make a difference. Plus the AF module is two generations beyond the K-5's.

12-02-2015, 10:03 AM	#13
DDoram Site Supporter Join Date: Jan 2009 Location: Edmonton, Alberta Canada Posts: 632	I have both the DA 16-85 which is a great lens and the Sigma 17-50 (f2.8). Both are great lenses; the Pentax is used as a general walk around outdoors while the Sigma is used for events due its constant f2.8.

12-02-2015, 10:07 AM	#14
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,695 Original Poster	Originally posted by audiobomber Don't judge the 17-50 until you try it on the K-3. The K-3 has three f/2.8-sensitive AF sensors, the K-5 has none. That alone will make a difference. Plus the AF module is two generations beyond the K-5's. Don't get me wrong, it's performing great on the K5, just not quite so consistent on AF accuracy as the 16-85 - specifically, close focus (5 - 6 feet), wide open at 50mm in fairly poor light. I tried it today on the K3 and it's definitely better than on the K5 - but I think the 16-85 still has the edge on accuracy. That said, I'm delighted with the Sigma - a really nice lens considering the street price.

12-02-2015, 10:10 AM	#15
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	Originally posted by BigMackCam Don't get me wrong, it's performing great on the K5, just not quite so consistent on AF accuracy as the 16-85 - specifically, close focus (5 - 6 feet), wide open at 50mm in fairly poor light. I tried it today on the K3 and it's definitely better than on the K5 - but I think the 16-85 still has the edge on accuracy. That said, I'm delighted with the Sigma - a really nice lens considering the street price. Did you try AF Adjust with the K-3? The lens won't necessarily need the same correction on different bodies.