[Gondo]

Hello. I'm an owner of a K5-II. It's my first ever DSLR and for a few years have been using the DA 18-135 Kit lense. I would now like to buy some good glass.

I'd like something in the 16-50mm range and at least an F2.8. What I am wanting is a general walkaround lens for landscape, street, portrait, etc... I'd also like to do some sky shots at night. The 16mm wide end more for the sky shots. My current kit lens cannot take night shots very well due to the low Aperature size.

I intend to do some night shots in winter with freezing temperatures. Will the weatherproofing of Pentax lenses be beneficial or can I get away with a Sigma? I'd also bring the lens to the beach or on hikes where there is potential for sand and rain.

A couple of lenses the peak my interest are:

Sigma 18-30mm F1.8 (worried about lake of weatherproofing)
DA* 16-50mm F2.8 (worried about reliability SDM issues)
Sigma 30mm F1.4 Prime (low F value but a prime)

A few questions. Is the reliability of DA* lenses still an issue in 2017? Can I get away with a sigma in rain, snow, etc... without a bag or any sort of protection? Would a prime be weatherproofed or is rain still an issue even with a prime? I've never owned a prime so I'm not sure if it's worth it over the zoom as a walkaround lens. But the F1.4 intrigues me for the astro sky shots.

Any suggestions. In the future I'm planning on getting either a good 135-250mm as a walkaround or possibly a 300mm prime DA* for the telephoto end of things for moon shots and wildlife.

Money is not an object. I want something that will do the night photography in freezing temperatures and snow flurries, but I want something durable so the DA* issues worry me. The low F value of Sigma intrigues me but they are not weatherproof.

Thanks for any help.

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Last edited by MarkJerling; 08-09-2017 at 04:37 PM.

[aslyfox]

if there is no concern over a budget

perhaps for now:

HD Pentax-DA 16-85mm F3.5-5.6 ED DC WR

but it isn't a 2.8

down the road for wild life, moon etc

perhaps:

HD Pentax-D FA* 70-200mm F2.8 ED DC AW

or


HD Pentax-D FA 150-450mm F4.5-5.6 ED DC AW

[Wasp]

The Sigma 18-30mm f/1.8 would be my choice for landscapes, especially in low light conditions. But it is a bit short for portraits. For that I would go with a separate prime - an 85mm f/1.4 if the budget allows. For something more versatile, perhaps the Sigma 50-150mm f/2.8 would suit your needs.

[twilhelm]

SDM doesn't have the issues it once did, and I have an original DA 17-70 that has never given me a problem, what I'm saying is if that is the lens you think will work best, go with it. The WR is a necessity if you are going to be out in rain and snow in my opinion and I don't believe the Sigma lenses are sealed. Although not quite as wide and not a constant aperture, the HD DA 20-40 would be a good lens to consider, WR, limited metal construction and with DC AF. Plus it produces some amazing images.

[Na Horuk]

The point of DSLRs is to have many lenses, each one for the specific situation you need.
SDM has been fixed on new lenses. There is serial code thread for some SDM lenses where you can see which serial numbers are good.

Do you actually need WR? Do you go out in drizzle, rain? If no, get Tamron 17-50mm f2.8. If you need WR, get DA* 16-50mm f2.8, with high serial number and long warranty.

Get DA 50mm f1.8 for portraits. You usually don't take portraits in rain (ruins makeup, clothes), so you don't need WR. Or used FA 50mm f1.4.

[timw4mail]

I would suggest a prime lens closest to your favorite focal length. 30/35mm (on APS-C) is about as close as you get to the field of view of a 50mm (full frame).

Zooms are definitely handy, but primes give you larger apertures, and generally somewhat better image quality.

[eminker]

I have the DA* 50-135mm F2.8, FA* 60-250mm F4. and FA* 24mm F2. I have not had any SDM issues as yet. I've used them in sub zero cold Adirondack winter carnivals and in snow flurries/drizzle without issue.
For Sky Shots, you may want to consider a dedicated UWA manual lens like a Samyang 14mm but the FA* 16-50mm should be fine as well. Easiest way to get a feel for what works for you, may be to rent your top three choices.

[VoiceOfReason]

The Sigma 18-35 f/1.8 is a lens in a class all its own compares to the others. If you can forgo the WR I'd do it, but if you want WR go with the Pentax DA*16-50. I had one and it was pretty decent. I'd almost consider the Pentax DFA 24-70 as well.

[DeadJohn]

Astro is a special niche and some great daytime lenses work poorly for the night sky.

Strongly consider the Samyang/Rokinon/Bower 14mm f2.8 for astrophotography. They are all the same lens with different brand names painted on. 14mm is wide enough for sharp 30 second exposures of the sky without an astrotracer. This lens has notably low coma distortion which is important for stars. The manual focus has a fairly long throw which helps to nail focus. It's not weather-resistant but cold will be fine.

Keep your 18-135 for general walkaround. That already gives you reasonably good image quality and weather resistance.

If you want f2.8 for handheld low light or thin depth of field, add a 3rd lens. The Pentax DA* 16-50, Sigma 17-50, Tamron 17-50 are all valid options. Or go with a FA 43/1.9, DA 50/1.8, FA 50/1.4 and you can get even narrower depth of field. The primes are not as versatile but you already have the 18-135 for versatility.

[VoiceOfReason]

The Sigma 18-35 f/1.8 Art lens does have excellent coma correction as well. I forgot to add that. It is a great astro lens for wide stuff.

[jatrax]

If money is no object then just get the DA*16-50 and be done fooling around. It is an excellent lens. SDM does have a bad reputation, but there have been almost no issues in the last few years. Less issues perhaps than with other brands or lenses yet the stigma of SDM failure remains. Based on postings here the DA 16-85 has had more failures than the DA*16-50 over the last two years. Not that there were many of those either.

[ChatMechant]

The 16-50 is a fine lens. Get one that has been converted to screwdrive (or do it yourself) and don't worry about SDM failure ever.

[disconnekt]

Depending on your budget, I'd suggest the Tamron 17-50mm f/2.8 for the wide to normal range, and for portrait lenses if you don't mind using manual prime lenses go there's the Samyang/rebrands 85mm f/1.4 and Mitakon's 85mm f/2 (they even have a f/1.2 lens) or Pentax's 50-135mm f/2.8

[RoccoStiglitz]

Any plans to go full frame in the future?

[Blacknight659]

If money isn't in the way, you may consider a lens combo...

16-85 and a 14mm 2.8. The 16-85 is noted for being a very very nice lens and the 14mm will take care of the night photography.

But if you want one lens, go with the 16-50. You can convert to screw drive if the motor fails ( How To: Convert SDM to ScrewDrive + Video - PentaxForums.com ).