[richard0170]

I am in a position to treat myself to a new prime for my K3. I currently have the DA 35 mm lens, the IQ of which is plenty good enough for my use, but its not a focal length I feel comfortable with. I prefer something around the 35 mm equiv. of 40-45 mm. I currently use a pka 28 mm f2.8, which is OK, but I would like AF and something a bit faster. I am currently torn between a Sigma 30 mm f1.4 EX DC for around £200, a Sigma 30 mm f1.4 Art for £370-£400 or if I am really lucky I might be able to snag a Pentax 31 mm ltd. for under £500. To get the Pentax would be nice but I can't justify paying above £500 for it. I shoot mainly in the aperture range f4 -f8, so I don't need the very fast aperture of the Sigma. The Sigma 28mm F1.8 Ex DG would also fit the bill,and can be had for a reasonable price, but its huge.
I would really love some feedback from any users of the above lenses, before I make any decision.

[pepperberry farm]

I recently found myself in a similar quest - looking for a standard (ish) prime, and was considering the 30mm options from Sigma also..

what I bought was a Sigma-refurbished 28mm f1.8 EX DG for considerably less than either of the 30mm options you are looking at - I have found that it's a very competent and useful lens, especially it's close-focusing abilities...

[08amczb]

A month ago I did a similar decision. I've choosen the FA* 24 F2.0. I realy like the focal length, and the IQ is outstanding from F4. The IQ in the range of F2.8-F4 is good, I use the lens generaly with these apertures. Under F2.8 the lens makes a glow around the sharp image, this isn't what current lenses do. I would buy this lens again if I had to make the decision again. This is the best 35mm eqv. lens currently available for Pentax APS-C (I think).

[aslyfox]

2 suggestions

use the info under the " lenses " link above to research

and check out the Market Place when you decide - I have had good luck there

Personally I have no experience with those prime lenses mentioned by the OP ( my smallest is the 40 mm XS pun intended )

[pres589]

This is a focal length area that I feel is woefully under served today in k-mount land. Something like 24mm to 30mm, on crop, seems like a great place to have some primes and Pentax doesn't do that currently. So, what to look at;

Sigma 24mm Super-Wide II AF - small, sharp, noisy AF, not known to be rugged (don't drop it or it falls apart).
Pentax FA*24 - large diameter, f2.0 max aperture, bit of distortion, seems awesome but they're getting old and some folks don't like the IQ
Pentax F 28 - small, sharp, noisy AF, seems like an excellent lens with a max aperture of f2.8.
Pentax FA 28 - slightly larger than the F, different optical design, I like the images that I've seen from the F more than the FA.
Sigma 28mm f1.8 - see pepperberry's statement above. This is not remotely small
Sigma 30 EX - Not sharp on the edges, fast f1.4 max aperture, very wide ranging emotions on how well the AF works based on reviews.
Sigma 30 Art - different optical design than the EX, less sharp on center, more sharp on edges. Still an f1.4 len, possibly worse working AF.

Out of all of them, the Super-Wide II and the FA*24 interest me the most. If I was still shooting music shows in dark bars, that Sigma 30 EX would probably be the lens for me. I have a trio of manual 28mm primes and they're nice on crop but 24mm seems like an even sweeter spot for a do-all prime. All of the above are in the User Reviews for further reading.

[mattt]

I will throw another vote in for F 28/2.8. It's an ugly lens with brilliant glass. I sold a copy which I have regretted since. But I see it often enough in the $175-$200 cdn range at shops that I regularly consider re-acquiring.

[pres589]

I will throw another vote in for F 28/2.8. It's an ugly lens with brilliant glass. I sold a copy which I have regretted since. But I see it often enough in the $175-$200 cdn range at shops that I regularly consider re-acquiring.

The thought of having local shops with used Pentax gear that I might want to buy, and then pricing like that? I nearly fell out of my chair reading this.

The F 28/2.8 does seem like an excellent lens. I just wish it was, you know, about 24 or 25mm and offer something faster than f2.8 for greater DoF options. Basically I want a brand new FA*24.

[Kozlok]

I have the Sigma EX30/1.4 and the FA31. The Sigma is sharper in the center at all apertures. The Pentax is sharper in the corners and better for flare, and has better colors. Portrait use (centered) the Sigma is better, for anything else, the 31. The ART 30 is supposed to be better than the EX in the corners, but worse in the center. Truthfully all three should take nice photos.

I will warn you though, the Sigma really is terrible in the corners, about 1/3 of the image width is just awful. Not a problem with certain photos, huge problem with others.

[bdery]

But I see it often enough in the $175-$200 cdn range at shops that I regularly consider re-acquiring.

Which shops are those? At 175$, I'd acquire it in a heartbeat.

To answer the original question, if the 31 is within your budget, i'd select this one without second thoughts.

[savoche]

Sounds to me you want a 31. If that's the case you shouldn't buy something else. You'll just end up buying the 31 later on anyway. It should be possible to find one under £500 with some patience.

(I'll just add that, good as the 31 is, I tend to pick the FA28 more often due to its small size. The 31 is for when I need that special transition from in-focus to oof.)

[normhead]

I will throw another vote in for F 28/2.8. It's an ugly lens with brilliant glass. I sold a copy which I have regretted since. But I see it often enough in the $175-$200 cdn range at shops that I regularly consider re-acquiring.

What shops?

[ChristianRock]

Honestly from looking at the original post, I would recommend looking at the DA 21mm Limited.

[microlight]

The alternative, if a zoom could work for you, is to try and find a second-hand HD DA20-40 Limited that's in your price range. It would solve your wish for use in the f4-f8 range and give an infinitely variable viewpoint down to 20mm from the 'normal' POV of around 33mm - plus a little in the tele end too. And it's as prime-sharp as a sharp thing - it's better than my DA35 at 35mm.

[normhead]

Honestly from looking at the original post, I would recommend looking at the DA 21mm Limited.

Me too. My two travel primes for my K-3 are the 21ltd and 40 XS. With the 100 macro and 1.4 TC, it's really nice walking around kit.

[Ishpuini]

During the first year of my photography training we were required to use 35mm only (in my case the FA35/2). And I agree with you: 35mm always felt too strict to me as a standard field-of-view on APS-C. Once the ban was lifted for the next three years of the course, I replaced it with the FA31/1.8, which made a world of difference. I used mostly that lens and a 24mm for my standard FoV photography.

However, more recently, the DA20-40 has taken the place as a preferred walk around standard lens. Obviously this is not a fixed focal length lens, but somehow, to me, it feels like one. Probably due to its limited zoom range, and its short and long ends not really being short or long. It feels like a 30mm lens with some framing flexibility. I've since become a huge fan of this lens!

hth, Wim