[elho_cid]

Totally wrong.

why? based on data from a lens renting company that was posted on some forums here the days of 16-50 misaligned and failing are over. Also EF-S 17-55/2.8 had such problems in early production and newer ones are great and reliable.

[oliver939]

few more question to the owners:
is the sigma 17-50 well recognize by the K5 and does the EXIF data are correct?
This is important to know (my sigma 10-20 is shown with straneg exif in LR).

how does this sigma compare with the tamron 17-50 f2.8?

[simico]

why? based on data from a lens renting company that was posted on some forums here the days of 16-50 misaligned and failing are over. Also EF-S 17-55/2.8 had such problems in early production and newer ones are great and reliable.

Misaligned lenses are a past, that's true. But you wrote "Nowdays the Da*16-50 are far better, including better SDM drive. The CA were more pronounced on K10D than on later bodies." and that's not true at all. The optics and thus the image quality is exactly the same, SDM also isn't any better since it's exactly the same. CA is still horrible on newer bodies.

The new Sigma AF 17-50mm f/2.8 HSM DC EX OS spanks the DA* 16-50, even if the fanboys don't like it. I found Tamron's 17-50 and 28-75 image quality to be as good as (and in some areas slightly better than) DA* 16-50. This is all from personal experience, after personally trying out these lenses. I wish the newest Sigma was in stock when I was looking for a 2.8 stamdard zoom.
As you can guess I'm not satisfied with my DA* 16-50, I'd exchange it for the new Sigma or a good copy of Tamron 17-50 in a second.

[elho_cid]

I have not photographed extensively with lots of those fast zooms but from those I used my rating would be:
1/ DA*16-50
2/ canon EF-S 17-55
3/ Tamron 17-50
4/ sigma 18-50 DC

I was skeptical about the DA* as well but the new production is better indeed. Perhaps the CA are also related to the alignment but I saw lots of them on an old DA* I tried with K10D and I passed this lens.
Not long ago I met a friend with new Da*16-50 and I tried it with my new K-5. Absolutely brilliant. I didn't expect it to exceed the image quality I'm used to with Canon lens.
Here is the thread about increased reliability:
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/121718-superso...nsrentals.html

[philip100]

In standard zoom lenses, my rating is:
1. Sigma 17-50mm f/2.8
2. Tamron 17-50mm f/2.8
3. Pentax *16-50mm f/2.8

Why? I always compare price to quality:

Sigma:
-impressive imaging quality and sharpness (best of those 3 lenses)
-very good build quality
-OS (more effective than SR)
-adequate price

Tamron:
-adequate price
-very good sharpness and imaging quality

Pentax:
-very good imaging quality
-very good build quality
-Sealing
(but not adequate to price at all)

[Tommot1965]

Hello everyone. I am new to Pentax forums.
Does anybody have actual experience with the K-5 and Sigma 17-50 f/2.8 EX OS HSM, specially about AF function . Do they work well together K-5 and Sigma ?
Thanks

Fabio

Im lucky enough to own the K5 and the sigma 17-50 OS.

the work very well together , the AF is good and the HSM is very quiet .

the lens is very sharp, across all zoom focal lengths , and at wide apertures

[Tommot1965]

few more question to the owners:
is the sigma 17-50 well recognize by the K5 and does the EXIF data are correct?
This is important to know (my sigma 10-20 is shown with straneg exif in LR).

how does this sigma compare with the tamron 17-50 f2.8?

not sure what your after here?

Photo me shows the lens as a "Pentax lens type Da or Da*"
lens Name/Id is..... "unkown"


in all the images I've taken so far, they show the Focal length of the lens correctly and the aperture ,

[Deimos]

Tamron 17-50 is great

[Jeff Charles]

Tamron 17-50 is great

How's the focus speed? I use one on a D90. It's very good optically, but slow focusing.

Jeff

[pop4]

few more question to the owners:
is the sigma 17-50 well recognize by the K5 and does the EXIF data are correct?
This is important to know (my sigma 10-20 is shown with straneg exif in LR).

The lens comes up as "unknown lens" when I filter by metadata in LR3.3, regardless of being shot by a K-5 or K-7.

[simico]

Not long ago I met a friend with new Da*16-50 and I tried it with my new K-5

My DA* is also brand new on a brand new K-5. IQ at F2.8 sucks compared to any other 2.8 standard zoom.

[Croc]

Misaligned lenses are a past, that's true. But you wrote "Nowdays the Da*16-50 are far better, including better SDM drive. The CA were more pronounced on K10D than on later bodies." and that's not true at all. The optics and thus the image quality is exactly the same, SDM also isn't any better since it's exactly the same. CA is still horrible on newer bodies.

The new Sigma AF 17-50mm f/2.8 HSM DC EX OS spanks the DA* 16-50, even if the fanboys don't like it. I found Tamron's 17-50 and 28-75 image quality to be as good as (and in some areas slightly better than) DA* 16-50. This is all from personal experience, after personally trying out these lenses. I wish the newest Sigma was in stock when I was looking for a 2.8 stamdard zoom.
As you can guess I'm not satisfied with my DA* 16-50, I'd exchange it for the new Sigma or a good copy of Tamron 17-50 in a second.

i wish people stop posting comments like this, if i didn't see comments like this few times over last year i would never go near da* 16-50 because truth is that misaligned lenses are NOT things of the past, i just had two copies over last 2 months that were decentered, brand new from current production, one was so badly decentered it almost started all the way from center.
i don't get how company like pentax can put out defective product like this for years without getting this issue REALLY sorted.

[Armanius]

Im lucky enough to own the K5 and the sigma 17-50 OS.

the work very well together , the AF is good and the HSM is very quiet .

the lens is very sharp, across all zoom focal lengths , and at wide apertures

How does the Sigma 17-50 balance on the K5? Is the lens big on the K5? I think it's 3.6" in length (which is not bad), but it's 3.3" in diameter, and it takes a 77mm filter.

Can you post a photo of the K5 with the Sigma 17-50 mounted on it? Thanks!

[elho_cid]

i wish people stop posting comments like this, if i didn't see comments like this few times over last year i would never go near da* 16-50 because truth is that misaligned lenses are NOT things of the past, i just had two copies over last 2 months that were decentered, brand new from current production, one was so badly decentered it almost started all the way from center.

I'm sorry to hear that yopu had this experience. I believe it is real on the moon where you live. But I really experienced a great DA*16-50 and wanted to share my optimism. Why should it be forbidden to share positive experience?
The Tamron, when new, may really have great optical performance. But what about after 2 years of usage? With it's built quality?

[Armanius]

The Tamron, when new, may really have great optical performance. But what about after 2 years of usage? With it's built quality?

It does have a six year warranty. Although I've never owned a Tamron lens (or Sigma lens) before. Very tempted to get one as it's much cheaper than the Pentax equivalent.