Suggestions and opinions concerning a zoom lens for my K3II

candeloromauro · 01-11-2016, 04:54 AM

Hi,
I am new in the website, so hi to all!

I would like to ask a question concerning lenses.
I have a pentax k3-II and I would like to buy a good lens to take pics in low-light conditions, specifically for concerts.
I was looking at a 24-70 f.2.8 or something like that and I found those 2 options that seems affordable (I would buy a used lens):
Sigma 24-70mm F2.8 IF EX DG HSM Lens Reviews - Sigma Lenses - Pentax Lens Review Database
and
Tamron 28-75mm F2.8 AF XR Di LD Macro SP Lens Reviews - Tamron Lenses - Pentax Lens Review Database
I don't understand exactly why the price different is so high, and what parameters I should consider to make a decision.

Moreover, what would you suggest? Maybe you also have other suggestions?

Any suggestion would be great and very appreciated!!!
Thank you very much for your help!
Mauro.

**TER-OR** · 01-11-2016, 08:56 AM

The price difference - Sigma tends to be a bit more expensive, and this is a HSM motorized focus lens. Sigma's motors tend to be very good.

**boriscleto** · 01-11-2016, 09:33 AM

The 24-70 is 4 mm wider and HSM. 4 mm doesn't sound like a lot, but in wide angle lenses a few millimeters is a big difference. In this case the difference between being a wide angle to telephoto zoom and a normal to telephoto zoom. Notice that the horizontal FOV for the 24-70 is 56 degrees @ 24mm, the FOV for the 28-70 is 50 degrees @ 28mm...

**Apet-Sure** · 01-11-2016, 10:27 AM

After reading reviews for both the Tamron and the Sigma, I've had the Tamron on my wish list for a while. It seemed to be the best bang for the buck for my purposes.

It seems to me that autofocus performance would be an important consideration when shooting moving performers at a concert. Although one reviewer rates the Tamron a 5 and two rate it a 6 in this category, many rate it at 9 and 10. I did a little statistical analysis of all the review ratings. Throwing out the lowest score (5) and one of the 10s, I came up with an average score of 8.56. It is interesting to note that the pictures posted by member ZoeB in her review of the Tamron were taken at a concert(s).

However, the Sigma HSM autofocus is reported to be very fast and accurate. To quote reviewer jackassp, "AF via HSM is silent and fast, and performs very very well in low light." Low light performance can be important at concerts.

Bottom line, how critical is it for you to get the highest percentage of 'keeper' shots? If I was shooting promo pics for the band I would spend the extra money for the Sigma. Otherwise I'd get the Tamron and maybe miss a few 'keepers'. Both lenses seem to have very good image quality. Disclaimer - I haven't used either of these lenses.

Last edited by Apet-Sure; 01-11-2016 at 10:36 AM.

**TER-OR** · 01-11-2016, 12:25 PM

I have a Sigma 28mm f1.8 macro - my only Sigma lens. I have rented a Sigma 8-16 and may eventually buy that special lens. I have only used a lower-end Tamron zoom on my old K10 so I can't comment on their quality. Sigma is good though, from my experience.

Another factor though is the K3 has a much faster screw-focus than previous models so the Tamron may well perform as well as the motorized Sigma now.

I'd note, though, that 28mm is pretty "normal" and not really wide-angle on a cropsensor. If you need wide-angle for stage work, this may be too tight. 24mm may be a bit tight, too. In that case something like the 16-45 could be better.

**Rondec** · 01-11-2016, 12:34 PM

24-70 is quite a bit wider than 28-75. Tamron is also screw drive and an older model. As to whether or not having HSM, a little wider lens are important depends on the photographer.

Unregistered User 8 · 01-11-2016, 03:12 PM

Hi Mauro. Welcome aboard the forum. You have hidden your introduction inside a question !!! Looking forward to seeing some of your photographs with the zoom you choose.

mikeSF · 01-11-2016, 03:48 PM

Welcome to the group

candeloromauro · 01-12-2016, 02:59 AM

Originally posted by TER-OR

The price difference - Sigma tends to be a bit more expensive, and this is a HSM motorized focus lens. Sigma's motors tend to be very good.

Thanks TER-OR, sorry for the basic question, but basically, if you buy a motorized lens, than is the motor of the lens to be used, and not the one in the camera, right?

candeloromauro · 01-12-2016, 03:12 AM

Hei,
thanks pjv and mikeSF! I attach a picture of the last solar eclipse, taken in Trondheim, Norway. I took it with my Pentax Kx, that went to pension in October to give space to my new K3II. Hope you enjoy it!
And thanks all for the comments.

Basically, to summarize, the embedded motor and the overall quality of the Sigma are increasing the price. Moreover I should consider the 4/5 mm difference when it comes to zoom limits.

Sorry for the question (that may be trivial), but if you purchase a motorized lens, then the camera motor is basically bypassed (since the lens one is used), correct?
Do you know if the Sigma mounts a motor (or should I talk in general about autofocus?) that is better than the K3II? At this point I think that this could make the difference in the evaluation.
I think that would be nice to have the opinion of someone that tried it out with one of the latest pentax, since the link to the Sigma lens is quite outdated (2012), so maybe could have been very good at that time, but maybe not so good anymore, if compared to the advances in the Pentax autofocus and cameras.

ps. since I'm an amateur, I'm open to any comment, so please, just speak your mind out and tell me if I say something that is not correct.

Mauro.

Name: eclipse.jpg
Views: 295
Size: 27.9 KB

Name: eclipse.jpg
Views: 295
Size: 27.9 KB

**TER-OR** · 01-13-2016, 06:43 AM

Originally posted by candeloromauro

Thanks TER-OR, sorry for the basic question, but basically, if you buy a motorized lens, than is the motor of the lens to be used, and not the one in the camera, right?

That's correct. The lens has a focus motor and doesn't use the screw-drive. Most don't even have drive screw focus mechanisms, just the motor. The only motor focus lens I have is the 18-135. It's really nice, essentially silent and fast. That lens doesn't seem to hunt as much OR I just don't notice. I will say, though, the focus hunt with the 55-300 is much faster with the K3II than the K5.

Sigma, from what I've read, has a well-regarded motor system.

candeloromauro · 01-13-2016, 04:52 PM

Originally posted by TER-OR

That's correct. The lens has a focus motor and doesn't use the screw-drive. Most don't even have drive screw focus mechanisms, just the motor. The only motor focus lens I have is the 18-135. It's really nice, essentially silent and fast. That lens doesn't seem to hunt as much OR I just don't notice. I will say, though, the focus hunt with the 55-300 is much faster with the K3II than the K5.

Sigma, from what I've read, has a well-regarded motor system.

Thank you very much!
Just last question, since you provided more info that made me more curious

So, what you're saying is that the mechanical focusing device is operated by the lens, but the software system that find the optimal focus is still the one on the camera, right? That would make the K3II better when the K5 in terms of focusing time (keeping the same lens). Am I correct?
Thanks TER-OR!
m.

**TER-OR** · 01-14-2016, 06:34 AM

Originally posted by candeloromauro

Thank you very much!
Just last question, since you provided more info that made me more curious

So, what you're saying is that the mechanical zooming device is operated by the lens, but the software system that find the optimal focus is still the one on the camera, right? That would make the K3II better when the K5 in terms of focusing time (keeping the same lens). Am I correct?
Thanks TER-OR!
m.

Yes, the new cameras have a couple focusing systems, both can be used depending on the mode you're using - phase and contrast detection. Where the K3II beats the K5 is in the improved physical and software for those systems AND the focus screw drive which is faster and more powerful than that in the K5. The motorized lenses, of course, focus only as quickly as the lens motors allow, the screw drive is not used. So, on my K5 the 18-135 is no slower than when on the K3II, but the focus may actually be faster because the autofocus systems are better. The 55-300 on the other hand is faster in both regards on the K3II.

The zoom is independent of the focus.
Camera controls focus, you control zoom. Lens just does what it's told (hopefully).

candeloromauro · 01-14-2016, 08:10 AM

Originally posted by TER-OR

Yes, the new cameras have a couple focusing systems, both can be used depending on the mode you're using - phase and contrast detection. Where the K3II beats the K5 is in the improved physical and software for those systems AND the focus screw drive which is faster and more powerful than that in the K5. The motorized lenses, of course, focus only as quickly as the lens motors allow, the screw drive is not used. So, on my K5 the 18-135 is no slower than when on the K3II, but the focus may actually be faster because the autofocus systems are better. The 55-300 on the other hand is faster in both regards on the K3II.

The zoom is independent of the focus.
Camera controls focus, you control zoom. Lens just does what it's told (hopefully).

Thank you very much,
and sorry, with "mechanical zooming" I actually meant the "mechanical focusing". My bad! (I corrected it in the previous message).
M.

01-11-2016, 04:54 AM	#1
candeloromauro New Member Join Date: Jan 2016 Posts: 24	Suggestions and opinions concerning a zoom lens for my K3II Hi, I am new in the website, so hi to all! I would like to ask a question concerning lenses. I have a pentax k3-II and I would like to buy a good lens to take pics in low-light conditions, specifically for concerts. I was looking at a 24-70 f.2.8 or something like that and I found those 2 options that seems affordable (I would buy a used lens): Sigma 24-70mm F2.8 IF EX DG HSM Lens Reviews - Sigma Lenses - Pentax Lens Review Database and Tamron 28-75mm F2.8 AF XR Di LD Macro SP Lens Reviews - Tamron Lenses - Pentax Lens Review Database I don't understand exactly why the price different is so high, and what parameters I should consider to make a decision. Moreover, what would you suggest? Maybe you also have other suggestions? Any suggestion would be great and very appreciated!!! Thank you very much for your help! Mauro.

01-11-2016, 10:27 AM	#4
Apet-Sure Site Supporter Join Date: Dec 2015 Location: Goldsboro North Carolina Photos: Gallery \| Albums Posts: 2,861	Which lens for concerts? After reading reviews for both the Tamron and the Sigma, I've had the Tamron on my wish list for a while. It seemed to be the best bang for the buck for my purposes. It seems to me that autofocus performance would be an important consideration when shooting moving performers at a concert. Although one reviewer rates the Tamron a 5 and two rate it a 6 in this category, many rate it at 9 and 10. I did a little statistical analysis of all the review ratings. Throwing out the lowest score (5) and one of the 10s, I came up with an average score of 8.56. It is interesting to note that the pictures posted by member ZoeB in her review of the Tamron were taken at a concert(s). However, the Sigma HSM autofocus is reported to be very fast and accurate. To quote reviewer jackassp, "AF via HSM is silent and fast, and performs very very well in low light." Low light performance can be important at concerts. Bottom line, how critical is it for you to get the highest percentage of 'keeper' shots? If I was shooting promo pics for the band I would spend the extra money for the Sigma. Otherwise I'd get the Tamron and maybe miss a few 'keepers'. Both lenses seem to have very good image quality. Disclaimer - I haven't used either of these lenses. Last edited by Apet-Sure; 01-11-2016 at 10:36 AM.

01-12-2016, 03:12 AM	#10
candeloromauro New Member Join Date: Jan 2016 Posts: 24 Original Poster	Hei, thanks pjv and mikeSF! I attach a picture of the last solar eclipse, taken in Trondheim, Norway. I took it with my Pentax Kx, that went to pension in October to give space to my new K3II. Hope you enjoy it! And thanks all for the comments. Basically, to summarize, the embedded motor and the overall quality of the Sigma are increasing the price. Moreover I should consider the 4/5 mm difference when it comes to zoom limits. Sorry for the question (that may be trivial), but if you purchase a motorized lens, then the camera motor is basically bypassed (since the lens one is used), correct? Do you know if the Sigma mounts a motor (or should I talk in general about autofocus?) that is better than the K3II? At this point I think that this could make the difference in the evaluation. I think that would be nice to have the opinion of someone that tried it out with one of the latest pentax, since the link to the Sigma lens is quite outdated (2012), so maybe could have been very good at that time, but maybe not so good anymore, if compared to the advances in the Pentax autofocus and cameras. ps. since I'm an amateur, I'm open to any comment, so please, just speak your mind out and tell me if I say something that is not correct. Mauro. Last edited by Tom S.; 01-12-2016 at 04:35 PM.

01-13-2016, 04:52 PM	#12
candeloromauro New Member Join Date: Jan 2016 Posts: 24 Original Poster	Originally posted by TER-OR That's correct. The lens has a focus motor and doesn't use the screw-drive. Most don't even have drive screw focus mechanisms, just the motor. The only motor focus lens I have is the 18-135. It's really nice, essentially silent and fast. That lens doesn't seem to hunt as much OR I just don't notice. I will say, though, the focus hunt with the 55-300 is much faster with the K3II than the K5. Sigma, from what I've read, has a well-regarded motor system. Thank you very much! Just last question, since you provided more info that made me more curious So, what you're saying is that the mechanical focusing device is operated by the lens, but the software system that find the optimal focus is still the one on the camera, right? That would make the K3II better when the K5 in terms of focusing time (keeping the same lens). Am I correct? Thanks TER-OR! m. Last edited by candeloromauro; 01-14-2016 at 08:10 AM.

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01-11-2016, 08:56 AM	#2
TER-OR Site Supporter Join Date: Apr 2009 Location: Dundee, IL Photos: Gallery \| Albums Posts: 6,699	The price difference - Sigma tends to be a bit more expensive, and this is a HSM motorized focus lens. Sigma's motors tend to be very good.

01-11-2016, 09:33 AM	#3
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,475	The 24-70 is 4 mm wider and HSM. 4 mm doesn't sound like a lot, but in wide angle lenses a few millimeters is a big difference. In this case the difference between being a wide angle to telephoto zoom and a normal to telephoto zoom. Notice that the horizontal FOV for the 24-70 is 56 degrees @ 24mm, the FOV for the 28-70 is 50 degrees @ 28mm...

01-11-2016, 12:25 PM	#5
TER-OR Site Supporter Join Date: Apr 2009 Location: Dundee, IL Photos: Gallery \| Albums Posts: 6,699	I have a Sigma 28mm f1.8 macro - my only Sigma lens. I have rented a Sigma 8-16 and may eventually buy that special lens. I have only used a lower-end Tamron zoom on my old K10 so I can't comment on their quality. Sigma is good though, from my experience. Another factor though is the K3 has a much faster screw-focus than previous models so the Tamron may well perform as well as the motorized Sigma now. I'd note, though, that 28mm is pretty "normal" and not really wide-angle on a cropsensor. If you need wide-angle for stage work, this may be too tight. 24mm may be a bit tight, too. In that case something like the 16-45 could be better.

01-11-2016, 12:34 PM	#6
Rondec Loyal Site Supporter Join Date: Mar 2009 Location: Gladys, Virginia Photos: Gallery Posts: 27,653	24-70 is quite a bit wider than 28-75. Tamron is also screw drive and an older model. As to whether or not having HSM, a little wider lens are important depends on the photographer.

01-11-2016, 03:12 PM	#7
Unregistered User 8 Closed Account Join Date: Mar 2015 Photos: Gallery Posts: 8,694	Hi Mauro. Welcome aboard the forum. You have hidden your introduction inside a question !!! Looking forward to seeing some of your photographs with the zoom you choose.

01-11-2016, 03:48 PM	#8
mikeSF Pentaxian Join Date: Jan 2009 Location: East Bay Area, CA Photos: Gallery Posts: 6,620	Welcome to the group

01-12-2016, 02:59 AM	#9
candeloromauro New Member Join Date: Jan 2016 Posts: 24 Original Poster	Originally posted by TER-OR The price difference - Sigma tends to be a bit more expensive, and this is a HSM motorized focus lens. Sigma's motors tend to be very good. Thanks TER-OR, sorry for the basic question, but basically, if you buy a motorized lens, than is the motor of the lens to be used, and not the one in the camera, right?

01-13-2016, 06:43 AM	#11
TER-OR Site Supporter Join Date: Apr 2009 Location: Dundee, IL Photos: Gallery \| Albums Posts: 6,699	Originally posted by candeloromauro Thanks TER-OR, sorry for the basic question, but basically, if you buy a motorized lens, than is the motor of the lens to be used, and not the one in the camera, right? That's correct. The lens has a focus motor and doesn't use the screw-drive. Most don't even have drive screw focus mechanisms, just the motor. The only motor focus lens I have is the 18-135. It's really nice, essentially silent and fast. That lens doesn't seem to hunt as much OR I just don't notice. I will say, though, the focus hunt with the 55-300 is much faster with the K3II than the K5. Sigma, from what I've read, has a well-regarded motor system.

01-14-2016, 06:34 AM	#13
TER-OR Site Supporter Join Date: Apr 2009 Location: Dundee, IL Photos: Gallery \| Albums Posts: 6,699	Originally posted by candeloromauro Thank you very much! Just last question, since you provided more info that made me more curious So, what you're saying is that the mechanical zooming device is operated by the lens, but the software system that find the optimal focus is still the one on the camera, right? That would make the K3II better when the K5 in terms of focusing time (keeping the same lens). Am I correct? Thanks TER-OR! m. Yes, the new cameras have a couple focusing systems, both can be used depending on the mode you're using - phase and contrast detection. Where the K3II beats the K5 is in the improved physical and software for those systems AND the focus screw drive which is faster and more powerful than that in the K5. The motorized lenses, of course, focus only as quickly as the lens motors allow, the screw drive is not used. So, on my K5 the 18-135 is no slower than when on the K3II, but the focus may actually be faster because the autofocus systems are better. The 55-300 on the other hand is faster in both regards on the K3II. The zoom is independent of the focus. Camera controls focus, you control zoom. Lens just does what it's told (hopefully).

01-14-2016, 08:10 AM	#14
candeloromauro New Member Join Date: Jan 2016 Posts: 24 Original Poster	Originally posted by TER-OR Yes, the new cameras have a couple focusing systems, both can be used depending on the mode you're using - phase and contrast detection. Where the K3II beats the K5 is in the improved physical and software for those systems AND the focus screw drive which is faster and more powerful than that in the K5. The motorized lenses, of course, focus only as quickly as the lens motors allow, the screw drive is not used. So, on my K5 the 18-135 is no slower than when on the K3II, but the focus may actually be faster because the autofocus systems are better. The 55-300 on the other hand is faster in both regards on the K3II. The zoom is independent of the focus. Camera controls focus, you control zoom. Lens just does what it's told (hopefully). Thank you very much, and sorry, with "mechanical zooming" I actually meant the "mechanical focusing". My bad! (I corrected it in the previous message). M.