[K-Three]

My 18-55 (1st gen, no WR) has gotten really stiff to focus, not sure if just old, or if it got whacked at some point. The cameras can't drive the focus past a certain rough point in the focus, I can feel it bind as I do it manually. I suspect a repair is more than it's worth, and I have an itch to buy something new anyway.

I have this focal range covered with a couple of other lenses, the 18-135, and the 18-250, I carry the 18-135 most everywhere with me. My wife occasionally shoots, and needs something in the short range, the 18-250 is usually too much size and range for what she needs or wants. I'm also thinking a ƒ/2.8 short zoom lens would be nice to have in the arsenal. While most of my work is outside, I do help out with some non-profits around here shooting indoor events, where flash is not appreciated. I've got fast primes I've been using, but a body with a short zoom might be a good tool too.

It looks like my options are the Tamron 17-50, the Sigma in the same range and the Pentax 16-50, after reading the PF shoot out between the three, I'm about to get the Tamron. While most of my collection is Pentax, I'm leery of the SDM issues that the 16-50 is known for,

The only other lens I'm finding in the range is the 20-40, but it's not constant aperture,
Working with a K5 &K3, not thinking about FF anytime soon.

Would appreciate the wit and wisdom of this group, other lenses that I might have missed?
Thoughts on the test results and personal experience with the various lenses?
Thanks in advance for your help,

[VoiceOfReason]

Sigma 18-35 f/1.8 Art. I love my copy. It's sharp even wide open, fast, and well built. Some have issues focusing (mine doesn't), but LV takes care of that.

[jatrax]

Thoughts on the test results and personal experience with the various lenses?

I shot with the DA*16-50 for years and would still be using it if I had not moved to the K-1. SDM was definitely an issue as evidenced by the numerous complaints back in the day. However, if you buy new there should be no issues whatsoever. When was the last time anyone posted about SDM failure on this forum? Back in the day, it was EVERY day. The new lenses are as robust as anything else out there. Used would be a different story but even if it does go out you can change it to screw drive and keep going. Or buy one used that has already been changed to screwdrive, the focus was IMHO just a bit faster with screwdrive than with SDM anyway. And I shot my both ways.

That's if you want the f/2.8. If not, take a good look at the DA 16-85.

IMHO, SDM failure is no longer a reason to not buy a new 16-50.

[UncleVanya]

I have the 16-50 f2.8 and the 20-40 f2.8-4 they are very different lenses. The 16-50 is quite a bit larger and heavier than the 20-40 (larger even than the 18-135). They both make great photos. The 20-40 is light and small but not constant aperture and has a shorter zoom range than the 16-50. In practice the larger lens is more versatile but in practical use I find the 20-40 to be quite useful and the size is very helpful when carrying a smaller bag.

[Alex645]

Iʻm a prime lens shooter, but the one go-to zoom Iʻd highly recommend, that would supplement your optics is the PENTAX HD DA 16-85mm f/3.5-5.6 ED DC WR.

Pentax HD PENTAX DA 16-85mm f/3.5-5.6 ED DC WR Lens 21387 B&H

One ED and three aspherical elements, HD and SP lens coatings, quick-shift focus control, DC AF motor, weather-resistant (11 seals), rounded 7-blade diaphragm, and an extra 2mm less on the wide end. Currently they are on sale if youʻre looking to buy new.

[Kozlok]

A used 16-50 is really quite inexpensive these days. They go for 300-400 or so from what I've seen lately. It's biggest let-down is flare, but for in indoor lens, it's not a problem. If you don't need the WR, the Tamron or Sigma are probably just as lovely. If SDM fails, convert to screwdrive and keep shooting. No matter which you pick, it will be fine.

[mikesbike]

You are looking for a wide-angle to moderate tele, in a fast zoom lens for indoor use without flash. For this you definitely need f/2.8, especially if movement is involved. More definitely if fast movement is involved, and also depending on how low the lighting. The next thing to consider is what FL you will actually need. Since you bring up the Tamron 17-50mm, apparently you've already concluded your actual need will be in that range. I have heard good things about the Tamron, that it delivers very-good to excellent results throughout its zoom range and apertures. Sometimes maybe defocused issues just in corners due to field curvature, but this shouldn't be an issue for the needs you describe.

[K-Three]

Thanks for the input,
The Sigma Art 18-35, ƒ/1.8 seems an interesting beast, but too big and heavy, also the PDAF focus issue scares me away. I need to be able to focus through a glass view finder.
The Pentax 16-85 has caught my attention, but has too much range overlap with what I already have, and no speed advantage,
Keep pondering and musing,

[Alex645]

The Pentax 16-85 has caught my attention, but has too much range overlap with what I already have, and no speed advantage,
Keep pondering and musing,

If youʻve never seen or used a lens in the 16mm focal length, it is really worth it. Go to a local camera store or BestBuy and check out ANY 16-85mm (Canikon) just to see it. Also at those focal lengths, speed is not so important and with speed will come size and weight.

I come from a film background, and I always wanted wider than 28mm. The 18mm is equivalent to 28mm; 17mm a compromised 25.5mm; 16mm is the 24mm equivalent. If this lens is for you, and youʻre trying to avoid focal length overlap, then wouldnʻt the Sigma 10-20mm f/3.5 EX DC HSM or Tamron SP AF 10-24mm f / 3.5-4.5 DI II make sense?

But if it is primarily for your wifeʻs camera, with you swapping with her, I would think the 16-85mm Pentax makes the most sense.

[aslyfox]

I have a suggestion guaranteed to spend your $$

consider contacting one of the rental companies - borrowlenses.com or lensrental.com [ I have had experiences ( all good ) with lensesrental ] here in the US and arrange to rent the lenses you are considering if they have it

those are the 2 companies I know of there may be others

advantage you can test out what you select yourself and determine how it handles in " real life "

disadvantage - cost

if you do rent, please post your impressions here

both of the company and process

and what you think of the equipment you try out

regardless of what you do, when it comes time to find a lens, if you are interested in " experienced " equipment, don't forget to check out the forum's market place " buy/sell "

[VoiceOfReason]

Thanks for the input,
The Sigma Art 18-35, ƒ/1.8 seems an interesting beast, but too big and heavy, also the PDAF focus issue scares me away. I need to be able to focus through a glass view finder.
The Pentax 16-85 has caught my attention, but has too much range overlap with what I already have, and no speed advantage,
Keep pondering and musing,

I've never actually had a problem with mine, and I was one of the early preorders. I always do through the viewfinder on mine. I will admit it is a pretty big lens though.

[TwoUptons]

I have the 16-50 and think it’s excellent. It is a big thing, but it makes great photos anywhere.

I occasionally use it with my K1 because of the WR and FL range, though it’s imperfect there...

On APS-C, I’ve found the 16mm end indispensable, and 50mm I’ve found ‘enough’ for most things. Any longer and I generally want a lot longer...

-Eric

[jeallen01]

FWIW, I got a pretty old Sigma 17-70 a few months ago for about $100 US, and I love it - the "go to" lens on both the K-30 and K-3 for general use.

[K-Three]

If youʻve never seen or used a lens in the 16mm focal length, it is really worth it. Go to a local camera store or BestBuy and check out ANY 16-85mm (Canikon) just to see it. Also at those focal lengths, speed is not so important and with speed will come size and weight.

I come from a film background, and I always wanted wider than 28mm. The 18mm is equivalent to 28mm; 17mm a compromised 25.5mm; 16mm is the 24mm equivalent. If this lens is for you, and youʻre trying to avoid focal length overlap, then wouldnʻt the Sigma 10-20mm f/3.5 EX DC HSM or Tamron SP AF 10-24mm f / 3.5-4.5 DI II make sense?

But if it is primarily for your wifeʻs camera, with you swapping with her, I would think the 16-85mm Pentax makes the most sense.

I've got a 15mm LTD, so I know of which you speak,
I also have a K18mm ƒ/3.5 for my old film gear that I had a lot of fun with back in the day, It's not as much fun on APSc as it was on film

[Alex645]

I've got a 15mm LTD, so I know of which you speak,

Actually 15mm for APS-C is even better! The day Ricoh releases a modern 20mm FF prime, will be a day to celebrate. Until then, thereʻs always the manual focus Rokinon 20mm or the 20-year old Pentax FA 20mm f/2.8.