[CWyatt]

I just added this review to the database, but seeing how there's been some discussion on standard lenses lately with the new 35mm, I thought this might be of interest here too:

If you want a fast (say, f/2 or faster) standard auto-focus lens on a Pentax camera, you options are limited to the renowned FA 31mm f/1.8, this Sigma 30mm f/1.4, or the FA 35mm f/2.

I find 35mm too long, the 31mm too expensive for my budget (unfortunately), and read it has relatively slow and noisy AF.

The Sigma 30mm f/1.4 gets mixed reviews. I've had it for a few months and have taken thousand of shots in many conditions with it on a K-7. I bought it for street photography and low-light photography. Here are my thoughts:

The build is typical Sigma EX, very good without being metal or sealed. Size and weight are actually very good for a f/1.4 lens. Still keeps a pretty compact set up with the K-7. At 62mm the filter size is very good for a fast lens as well.

IQ is very high in the centre right from wide open. This is great and one reason I bought a f/1.4 lens is to be able to use it at f/1.4. By f/2 to f/2.8 centre IQ is about as high as anyone could want. The extreme corners are never great, poor wide open (although hardly ever in the field of focus), and only get to a moderate level stopping down. It's certainly geared towards performing well in the centre wide open, and this is a trade off. Bokeh and contrast seem very good, although I don't study it and compare to other lenses.

IQ issues include a small amount of barrel distortion, and red/green CA at all f-stops. This is pretty easily dealt with. There can be a small amount of purple fringing around highlights, pretty much gone by f/2. Can flare a little bit sometimes, but is quite resistant to this. Note I never use the hood, to keep size down for street work. Bokeh can get some purple/green fringing, like many fast lenses, but is controlled.

AF speed is good, unfortunately the Pentax version of this lens is not currently HSM, but this also means the lens is a bit smaller (although it's the same price). I'm not sure why there is also an HSM version listed in the lens review section for Pentax. Low light focus can be iffy at times - probably more the K-7's issue.

Why there is no DOF scale is beyond me, I would love one and am considering painting it on myself. There is no quick-shift manual focusing like many Pentax lenses.

I think the price is very good new or second hand. Especially good if you need the speed, the performance to price at fast apertures is very good.

Overall: 8/10, great purchase, hardly ever comes off the camera. Great for my needs.

[yeatzee]

No images?

[CWyatt]

No images?

Good point, here are some: https://www.pentaxforums.com/forums/post-your-photos/121597-streets-dream-rec...ml?src=subsct2

And the vast majority of my recent work is with the Sigma 30mm:
Camus Wyatt | Latest

I don't know if 100% crops will add too much to points made above.

[nater]

If you want a fast (say, f/2 or faster) standard auto-focus lens on a Pentax camera, you options are limited to the renowned FA 31mm f/1.8, this Sigma 30mm f/1.4, or the FA 35mm f/2.

What, no shout-out for the Sigma 28mm f/1.8 EX DG Aspherical Macro? A full-frame (with aperture ring), autofocus, modern 28mm lens that sells for $350... and it never seems to get mentioned.

[CWyatt]

Ah correct, I overlooked that. Will edit the review.

When purchasing a standard lens I quickly dismissed the 28mm for my own needs, due to size, focus throw and overall performance. But it also looks a decent lens. Will also add the 30mm is an APS-C dedicated lens.

[DaveInPA]

I have this lens and I do like it alot...I don't use it enough.

This is one of my favorite photos I took with it last year at Thanksgiving...a photo of my daughter and brother sitting at the dining room table (K10D, f/1.4, ISO800, 1/45 sec, no flash):

[Nick Siebers]

How does this lens compare with the FA43 limited? Faster, yes, bigger, yes, but for overall use and especially image quality? Thanks! Nick

[switters]

The only thing that has discouraged me from using this as my "fast 50" equivalent is the rather low maximum magnification, at .10x (vs. .17x for the 35/2.4 and .16x for the 35/2). This isn't a huge problem, but I do appreciate the ability to work in close with a walkaround lens.

[Jonathan Mac]

As much as I´m tempted by this lens, the known (and acknowledged here) shortcomings make me want to wait for a v2 of it, which will hopefully address them. Thanks for the brief review though.

[switters]

Has there been any mention of a v2 of this lens?

[Jonathan Mac]

Has there been any mention of a v2 of this lens?

No, but I can dream of a fast, high-IQ, normal prime for Pentax can´t I?

[DogLover]

Well, Camus, I'm glad you're so pleased with "my" Sigma 30. Is it too late to rescind our transaction? I'm joking of course, but in all seriousness, this is the only lens I've ever regretted selling. I am very glad it went to a good home where it is getting the respect it deserves.

[switters]

Isn't that what the Sigma 30/1.4 is (provided you get a good copy)?

[CWyatt]

Well, Camus, I'm glad you're so pleased with "my" Sigma 30. Is it too late to rescind our transaction? I'm joking of course, but in all seriousness, this is the only lens I've ever regretted selling. I am very glad it went to a good home where it is getting the respect it deserves.

It's the one on the camera 90% of the time now, I'm a photographer sold on fast standards after this one.

No, but I can dream of a fast, high-IQ, normal prime for Pentax can´t I?

That is what I'd class this as. Better corner to corner performance is available at a price (thinking of the FA31mm here), but this Sigma still wins in the centre at open apetures. Also I'm shooting mostly street, so I'm not hugely demanding on corner to corner sharpness.

Has there been any mention of a v2 of this lens?

Not that I know of, and I'd be pretty surprised if there is any time soon, unless it's to introduce an HSM version for Pentax.

How does this lens compare with the FA43 limited? Faster, yes, bigger, yes, but for overall use and especially image quality? Thanks! Nick

I'd really compare it to the 31mm, I find 43mm an odd length for APS-C so never really considered it, and haven't used it. I really wished the DA 40mm (claimed as a 'normal') was more like 30mm.

[GregX999]

I just received a (lightly used) copy of this lens two days ago. I haven't shot anything "real" yet - just lame crap around my house, but first impressions:

1. Larger than my other lenses (18-55 kit and a couple of DA Limiteds).

2. Very sharp in the center (as has been noted).

3. Very nice build quality.

4. AF sometimes (1 out of 4 times) hunts in low light (nothing major, just 1 or 2 quick "corrections"). I have not noticed this with my other lenses, but I've also not tried to use them low light.

5. Mine back-focused a tad, set AF Adjust to +2 and it's perfect.

6. No quick-shift focusing, and no switch on the lens. So you have to hit the switch on the body to disengage the screw-drive (difficult to do while holding camera to eye). Would be a pain if you liked to use AF, but "adjust" at times.

7. Can't focus too close - about a foot I think.

Overall, I like it so far and I predict it will end up being my most used lens (being that it's a "normal" lens - aka: 45mm equiv.). Hopefully the AF/MF thing won't bother me too much.

I was trying to decide between this lens and DA35 Limited. I would like to have the close-focusing of the DA, but I want the f1.4 even more. (My only complaint with the DA Limited series is that they're all so slow - anything slower than f2 is slow for a prime - IMO.)