[lesmore49]

I'm thinking of getting a new lens for my K1. The choice boils down to the 31mm Limited..F 1'9 if memory serves me or the Pentax 24-70 F 2.8, which I understand to be a rebadged Tamron.

They're close in price and of course one is a prime, the other a zoom.

I like my photos to be as sharp as they can, I like a solid, well built robust lens.

I find zoom of course more flexible, but I'm ok with a prime. I've got both zooms and primes and I'm ok with both.

I do have a Pentax 28-105 zoom and I must admit this is one heckuva lens. Sharp, food focal length range. It's plasticky, but seems ok build wise.

I also have a 40 Ltd. 70 Ltd. , 50 macro, 50 normal (f 1.4) as well as other mostly ASP-C lenses. I know the 40 and 70 are ASP-C, but they seem to work well with the K-1...the 21 mm not so much, my 10-17 Fisheye..only at 17mm. I have the 18-135, 55-300...asp-c only, also the 150-500 Sigma...full frame.

I take pix mostly of vintage cars, trucks, motorcycles, landscapes, interior shots of people (mostly relatives and friends)....birthdays, Xmas, etc...that kind of event.

Please jump in and provide advice as to what things I should consider, your experiences , etc...

Thanks in advance,

Les

[jatrax]

Except for f/2.8 the 28-105 covers the 24-70 range. Mostly, unless you need wider than 28mm. Which the 31mm is not going to help with either.

Generally I prefer a good zoom over a bunch of primes and only use primes for special purposes. But in this case I would think about the 31mm instead of the 24-70. Unless you need the 24mm of course.

[UncleVanya]

Everything I read says the 28-105 is excellent and the 24-70 mainly has benefits in speed and wide angle. The post above is spot on. But how about looking at the 15-30? That would be an excellent indoor lens with more flexibility than the FA 31 for your needs.

It's big and heavy. But hey - the 28-105 is light right? LOL

[jatrax]

how about looking at the 15-30? That would be an excellent indoor lens with more flexibility than the FA 31 for your needs.

Good point. I would love to have the 31mm and maybe someday I will but I cannot justify the cost when other lenses provide more flexibility.

choice boils down to the 31mm Limited..F 1'9 if memory serves me or the Pentax 24-70 F 2.8

Since you already have the 28-105 what are you trying to do that the 24-70 or 31mm will do? You have the range well covered already. UncleVanya's suggestion of the 15-30 has a lot of merit. If you want the 31mm just because it is the 31mm Limited then sure, go for it. But if you are trying to fill out your lens bag I would look for what else I was missing.

[Sandy Hancock]

I would get the FA31 - it is ideal for the indoor stuff you mention and is also a very capable landscape lens. Since I got the DFA28-105 I have barely used my DFA24-70. I will most likely sell the latter.

I agree that the DFA15-30 is another consideration. It's a fabulous, versatile lens and Pentax's only weather sealed option in that range.

[UncleVanya]

I would get the FA31 - it is ideal for the indoor stuff you mention and is also a very capable landscape lens. Since I got the DFA28-105 I have barely used my DFA24-70. I will most likely sell the latter.

I agree that the DFA15-30 is another consideration. It's a fabulous, versatile lens and Pentax's only weather sealed option in that range.

Sandy - that's high praise for the 28-105 - good to know. Since you own both the FA 31 and the 15-30 along with a K-1 maybe you can give insight where one is better than the other?

[robjmitchell]

Between the 28-105 and your primes you have most ranges covered. I would go the 31ltd out of the two but the 15-30 should certainly be under consideration if you dont mind the weight. Of course if your patient and prefer primes they there will be a FF wide angle eventually. Probably 2019 at the earliest.

[Na Horuk]

I do have a Pentax 28-105 zoom and I must admit this is one heckuva lens. Sharp, food focal length range. It's plasticky, but seems ok build wise.

Sell the 28-105mm, sell the DA 40mm, and buy both FA 31mm and 24-70mm. That way you have a fresh new kit. Later get one of the ultra wides, maybe a 70-200mm if you prefer telephoto, and you're done!

From your post, OP, I get the vibes that you ultimately want a number of sharp primes rather than superzooms. Go down that path, primes are becoming popular again

[mikesbike]

Like Sandy, I would go for the FA 31mm f/1.8 Limited, unless you really need a faster zoom lens. It is a fast lens good for low-light situations, and it is even sharp wide open. It offers wide angle without being overly wide, which makes it very versatile for FF use. Its other imaging characteristics are stellar as well. It is much faster and even better for low light than an f/2.8 lens.

I have fast f/2.8 zoom lenses, but I only use them when I need that speed. Otherwise, I use my slower-but-excellent alternatives because unless needed, who needs to haul the weight? I also have some faster primes, including some Limiteds, and they are a joy to use, easy to carry, and can be there for situations where that extra speed is needed.

[Sandy Hancock]

Maybe you can give insight where one is better than the other?

Most of it is obvious from the specs. I would not be without either, and often pack them both for a day out. The photos below are all from the same trip.

The FA31 is much faster, much smaller, takes regular 58mm filters and is chock full of pixie dust.





The DFA15-30 gives you the versatility of zooming to the ultra-wide end and adds WR and silent focus when those features are important.

[YankeeDan]

I've got (and use) both. When you can zoom with your feet, use the 31mm. When you can't - use the zoom.

[pschlute]

Given what you have go for the 31mm f1.8 LTD. Many regard it as the finest lens Pentax ever made.

The 24-70 2.8 is a very fine lens which I like a lot. But it will duplicate your 28-105 with only 4mm of extra wide.

The 31mm Ltd has a quality that is difficult to describe. it is sharp even at 1.8, but stop down to f4 and it is astonishing. But that is not what makes the lens , the way it transitions to oof areas is what makes this lens special to me. It is is old technology though so that means screw drive AF which is fine by me. Also it will display chromatic aberation quite significantly if photographing against a bright sky, so be prepared to do some PP work. It has a built in hood which sometimes does not give the protection you may require.

However it is a classic and as a confirmed Pentaxian you will get one one day so why not now !

[dave2k]

I have the 24-70 and the 28-105. I'll take the 28-105 when I need to travel small / light, but I prefer the 24-70 in most cases. It has the wider aperture which is nice for a number of reasons and for landscapes 24 is quite a bit wider than 28. When I review the focal lengths of my landscape shots many are at 24, indicating that I really needed the extra 4 mm. It seems that you don't have any FF lens that wide so the 24-70 would fill that void.

[IgorZ]

Most of it is obvious from the specs. I would not be without either, and often pack them both for a day out. The photos below are all from the same trip.

The FA31 is much faster, much smaller, takes regular 58mm filters and is chock full of pixie dust.

some very nice photos!

[DeadJohn]

Pentax 31mm or Pentax 24-70mm ? ... I do have a Pentax 28-105 zoom and I must admit this is one heckuva lens ... I take pix mostly of vintage cars, trucks, motorcycles, landscapes, interior shots of people ... [snipped for brevity]

I think the FA 31 is better than the 24-70 for you. My reasoning follows.

What about the 28-105 do you want to upgrade? Better low light, thinner depth of field, or something else? I suspect 28mm is already wide enough for you or else you wouldn't be considering the FA 31. Therefore, buy the FA 31. It gives you sharpness, low light flexibility, thin depth of field when needed. It's a more distinctive lens than the 24-70. Your 28-105 already covers zoom, weather resistance, silent focus, quickshift focus so the 24-70 doesn't seem to add any special features for you.

Personally, I would do as others suggested and get the 15-30. Thta's because I like wide angle and find that even 24mm is not wide enough indoors and for close-ups of cars. If your 28-105 gets you wide enough, though, you'll probably love the FA 31.