[bofh]

Hello,

recently I purchased a K-5IIs in very good condition and paired it with the DA*16-50SDM.
Usually I photograph nature and landscapes, buildings, details which attract my attention and portraits of our cats.

Unfortunately my DA*16-50 is very soft at f/2.8, usable at f/4 (thanks to sharpening in post processing) and sort of OK at f/5.6-f/11 regarding the sharpness.
The CAs are also remarkable. I compared the images to images taken with my Samyang 35/1.4 and afterwards I wished I hadn't done that...

So I'm thinking back and forth what to do to, read the reviews (in particular the PF comparison between the DA*, the Sigma 17-50 and the Tamron 17-50).
The more I read the less decisive I become.

I'd like to have a fast standard zoom lens with AF. I don't mind whether it's screw drive or other technology and AF speed also isn't that important for me.
The image quality should be significantly better: sharper, in particular at f/2.8 or at least f/4 and less CAs would be good, too. Weather sealing is for me like fast AF: nice to have.
The focal range 16-50 suits my needs very well. Weight and size don't matter.
16mm at the short and would be very nice to have.

The new DA*16-50 would solve my problem, but regarding to the PF compatibility list stopping down won't work when paired with the K-5IIs.

What now?
Trying out another DA*, hoping that it could be a better lens? I don't like that thought.
With some attention at the light sources, the Sigma 17-50/2.8 seems to be a a candidate to replace the DA*.
Or perhaps the Sigma 17-70/2.8-4?
Or should I pay the price of the slower aperture at the long end to get a longer AND shorter focal length than the Sigma lenses and the Pentax 16-85/3.5-5.6 is the lens for me?

Please tell me your opinion.

Thank you!

E.

[ismaelg]

Hello,

I am very happy with my Tamron 17-50 f2.8 in my K5II

Thanks,
Ismael

[timb64]

I used a 16-85 extensively with a K5ii and was always very happy with the results.Mostly used it stopped down to f8 so the lack of speed in the lens was not an issue for me.

[AstroDave]

I'm a fan of the Sigma 17-50 over the Pentax. I've got both, and it was the 17-50 that went with me most of the time - but nowadays it's almost always the 18-135 (for my K-3).

The 16-50 and 17-50 date from my K-20 and K-5 days, so more typical for you, I guess. Of the two, it's the Sigma for me.

[ramseybuckeye]

I had a Sigma 17-50 2.8, although a good lens and I liked it, it was not really good at 2.8 either. I needed weather resistance so I ended up with the Pentax 20-40, less range, but so much better in every way that I sold the Sigma, the best tradeoff I ever did.

[nosillec]

Have you played with the AF fine adjustments settings? If so and you still have issues, you may have a bad copy, or if you bought used, maybe a damaged lens. Or the Samyang 35 is super sharp and maybe an unfair comparison

I have 2 DA* 16-50s (both bought used) one is screw drive with faulty weather sealing the other is SMC. Both take great photos once their limitations are understood. At 40-50mm 2.8 they're a little soft (more so if the subject is around 10ft/3m away, which seems to be a difficult spot for this lens to focus) but still usable and at 3.2 they're great. That said, if the sun is in front of me at all, I'm at 2.8, 40-50mm, and I'm trying to take a picture of something about 10ft from me, the picture is pretty much guaranteed to be unusable without serious luck and post-processing.

When got the first one, I was disappointed with the sharpness and CAs but after making the AF fine adjustments, and learning its strengths and weaknesses, I find it's on my camera more than just about any other lens other than the 43mm.

Comparing pictures taken on the 16-50 with the 43 at f3.2... With the 43, I can crop significantly if I want to. With the 16-50, I need to frame it right because cropping highlights the lens's limitations. Your comparison with the Samyang might not be reasonable.

[UncleVanya]

The 16-50 hasn’t ever been bad but I haven’t fallen for it either. I use the 20-40 plus da 15 more than the 16-50.

The 16-85 has a great reputation on the wide end in particular.

One of the 17-50 options is another possibility.

I always liked the DA 17-70 f4 as well.

[ZombieArmy]

I own a Tamron 17-50 that I find pretty acceptable. Though tbh I actually use my 18-55 kit zoom more often thanks to the WR and the fact that I actually think it's sharper at f8-f11 because I mainly use it for landscapes.

[ChristianRock]

My SMC DA* is very sharp at f3.2 already, biting sharp at f4 except at 50mm where it's just sharp, but it gets there at arounf f5. CA is mostly gone by f4.
I think you have a misaligned lens .

[UncleVanya]

Reading back - I think I agree with the last post. My 16-50 is pretty good except wide open at 16 where it is still not bad. Stopping down just a bit helps a bunch at 16mm. I don’t love mine but it does work reasonably well - but it’s big compared to what I like.

[Sholom]

I have both what I think is an "good" (optically and mechanically) copy of the 16-50 SDM (only recently starting to get slow to begin focusing after 10 years) and a 20-40. I like the photos from both on my K-5 but for many types of shots the 20-40 runs rings around the 16-50. Both lenses are at their best in the 20-35 range but the 20-40 has better color and less CA at 20 than the 16-50 does. The colors the 16-50 puts out are lovely but high contrast scenes like sunny day tree branches against a bright blue sky are uncorrectable in post: the branches turn blue. Flare at 16 is a problem and stopping down at 16 seems to just sharpen up the internal lens reflections. I bought the 20-40 to lighten my travel load and do still use the 16-50 for a lot of lower contrast, closer-up garden work, but if I am sure I won't need 50mm I take the 20-40 instead. Both my lenses seem to lose a bit of contrast at the long end but that is easily fixed in post. For taking photos of grandkids, the faster focus of the 20-40 is great, but my favorite lens for that purpose is the 43mm FA. For walk-around shooting, taking the 20-40 and throwing the 70mm DA into a pocket works well too.

[pres589]

I picked up a Sigma 17-50 and it seems decent at f2.8 and good at f4.


I kind of want the 18-35 f1.8 now instead. But maybe not enough to actually pull the trigger.

For general walk-around the Pentax 18-135 is a favorite of mine. For portrait work I would go with an f2.8 (or faster) fixed aperture zoom. Or primes.

[tibbitts]

I have had the 17-50 Sigma and Tamron. I found the Sigma definitely better, although I haven't found PDAF accurate enough at all focal lengths for f2.8. I haven't been able to adjust PDAF with a single setting for all combinations of focal length and subject distance. CDAF is fine, and manual focus is usually possible. PDAF on the Tamron is worse. For a while the lens would disconnect from the body entirely, but Tamron fixed that under warranty on the second try. They adjusted the AF during both attempts to fix the intermittent disconnect, and adjusted it the same both times... but neither time was accurate for my cameras. Since I have multiple bodies of different types and they all are inaccurate in roughly the same way with the same lenses, I'm assuming the technology is just limited in the accuracy it can reliably produce. I have two DA* zooms and neither of those can be adjusted to accurate enough PDAF to use them wide open either.

[BarryE]

A bit like you I started with the 16-50 and K5 and was less than happy with the lens. I was expecting more, especially at the edges. However, over time I did start to appreciate many aspects of the lens. I began to work with its 'weaknesses'. I stuck with it and when I was selling my work over several years I did sell many that I shot with it. For 'flower portraits', especially in/after the rain it was especially good - the portraits not needing edge sharpness at all. At f5.6 it was fine and for landscapes it worked well. I realised I'd grown to like it.

I don't have much use for it now. However, I keep it ticking over on a K3 and when the weather is poor it gets an outing and it does its job well. It feels nice, much better than the f2.8 lenses on FF.

It may not be for you, but maybe you could come to like it a bit more. Give it a hard workout before you abandon it ...

[Pål Jensen]

The SMC DA* 16-50/2.8 should be very sharp stopped down. If not, it is a bad sample....