Sigma 30mm F1.4

*dugrant153* · 06-30-2009, 09:18 AM

After falling in love with the DA*55 F1.4 and the OOF ability of shooting below F2.8, I've been desiring a really nice 30mm-ish lens.

The FA 31 Limited seems to fit the bill but I think it is way too expensive for me to purchase.

I've been looking at the Sigma 30mm F1.4 (and yes, I did check out the lens review section and have googled as much as I could so far) but am curious to know what you fellow Pentax users think of this lens?

For one thing, my concern is build quality. Has it improved? I have two used Sigma lenses and unfortunately one broke down, the other has 'sounds' in it (Sigma 50 F2.8 macro MF, Sigma 24 F2.8 MF)...

I'm particularly liking the 30mm focal length so I'd like to stick around there. I have the DA35 F2.8 but would like something a tad wider. (I also have the 55mm on the tele end, and the 21 Limited on the wide end).

deejjjaaaa · 06-30-2009, 10:10 AM

there are FF Sigmas in EX line like 24/1.8, 28/1.8

legacyb4 · 06-30-2009, 11:49 AM

I know the perfect solution!

Buy back the FA 28mm F2.8 and a new K7; from the high ISO samples I've seen, you should have no problems pushing ISO high enough to get the indoor handheld shots you need ;-)

deejjjaaaa · 06-30-2009, 11:52 AM

Originally Posted by legacyb4

I know the perfect solution!

that will be D700 then...

Erasmo · 06-30-2009, 11:58 AM

I have it and i like it, the build quality of the EX-line is surprisingly good.

Some test shots: Testing testing - a set on Flickr

*drerka* · 06-30-2009, 01:09 PM

Completely agree with Erasmo. Good lens for the money. Build quility is good. The lens hood of my 30mm comes off a bit light, but that really is a minor point. All in all a recommende buy if you want to play with a shallow DOF.

*dugrant153* · 06-30-2009, 03:01 PM

Originally Posted by legacyb4

I know the perfect solution!

Buy back the FA 28mm F2.8 and a new K7; from the high ISO samples I've seen, you should have no problems pushing ISO high enough to get the indoor handheld shots you need ;-)

haha... thanks, legacyb4. That thought did cross my mind.
I guess it's not so much about the shutter speed in lowlight as it is the ability to use F/2 when called upon. Although the FA28 is pretty sexy!

This whole 'idea' of the Sigma 30mm came about when I saw some pics on Flickr river with this lens... some of them were pretty ridiculously awesome.

Ideally, I'd like a DA*30 F1.7 or something. That would be fantastic! But don't think there's anything out like that just yet... Or for a while....

Erasmo and dreka, how is the manual focus feel on this lens? I tend to MF quite a bit these days.

dantekgeek · 06-30-2009, 04:47 PM

This is my go-to lens for all my low light work. Build quality isn't quite up to par with the Pentax Limited line, but I don't have many complaints other than that the manual focusing isn't as smooth as I'd like (not problematic, but not a joy either).

The most important thing to know about this lens is its very weird IQ distribution. Center performance is incredible, considerably sharp even wide open, and simply insane when its stopped down.

The tradeoff for this is particularly poor edge quality, especially at corners. This means you'll be getting distortion and much reduced sharpness even when you stop down a bit.

Even given its shortcomings, its a tremendous value if you're looking for a low light portrait lens. I wouldn't want anything else for shooting concerts and night street shots.

*dugrant153* · 06-30-2009, 05:45 PM

hehe... would you describe the MF feel as "sandy" or difficult to move?

As for the corner sharpness lost, I think this may be exhibited on my Sigma 24 F2.8, which (even when stopped down to F4) is very soft on one area. It could be a lens element out of alignment also. hmm...

By poor edge quality... does this mean that if my subject is in the corner, he/she/it will be strangely soft?

*farfisa* · 06-30-2009, 06:57 PM

I used a Sigma 30 for over a year on my K100D, sold it before I got my K20, so it's a little hard to compare directly to lenses I use now, but it's a good lens. Big, felt solid to me, nice focusing ring, and showed hardly any signs of use when I sold it.

The edge sharpness problem is a little overblown, I think. It's not as sharp as the centre, no, but it's not what I would call blurry or anything. Seems to do better with the real world than the focus chart.

It does the job isolating subjects and the bokeh is very smooth. However, its out of focus areas definitely lack the character of the FA limiteds and the DA*55, so if you're expecting a shorter DA*55 you're going to be a little disappointed.

The FA 31 is a little tempermental, has a little trouble with high contrast situations (fringing, blooming), but is overall the better lens.

ballgofar · 06-30-2009, 07:01 PM

This might be able to help you out:

Sigma AF 30mm f/1.4 EX DC (Pentax K) Review / Test Report

AntiBad · 06-30-2009, 11:09 PM

my copy of the sig 30mm was really bad in the edges.... very mushy, but very nice in the center. Perhaps it is just sample variation, but my copy was unusable in the edges in real world shots... just mushy and sucky.

also back focused.
good luck.

*dugrant153* · 07-03-2009, 02:13 PM

Thanks for that test report!

I'm planning to do a lot of manual focus, so the autofocus is a nice touch but not entirely necessary

As for soft around the edges... does that mean that if my model is closer to the very right end of the frame, she'll be soft and blurry even if I put the focus on her?

I've seen some pretty amazing pics on flickr river and it seems this lens definitely has a 'character' of it's own.

*ytterbium* · 07-03-2009, 03:05 PM

Just make sure you buy it somewhere you can get refund or exchange it easily.
I'd be cautious with k200d, because Sigma most likely reverse engineered some k10d camera so it would work best on it or k20d.
And be sure to check focus not only on some abstract test chart but at greater (4+ meters) distances too.
I wouldn't write off AF as well, since it is a lot harder to manually focus at 30mm than it is at some 50mm.

dantekgeek · 07-03-2009, 07:05 PM

Originally Posted by dugrant153

hehe... would you describe the MF feel as "sandy" or difficult to move?

As for the corner sharpness lost, I think this may be exhibited on my Sigma 24 F2.8, which (even when stopped down to F4) is very soft on one area. It could be a lens element out of alignment also. hmm...

By poor edge quality... does this mean that if my subject is in the corner, he/she/it will be strangely soft?

MF is definitely "sandy."

By edge quality, I don't mean just a reduction in sharpness, but actual distortion. For an example, see the corners and edge of the shot below.

Check out the difference between the center and the edges (look for the triangular windows in the buildings caused by distortion: downtown is sharp, east and west midtown is not)