[sTi]

Yes, it is big and heavy. I wish it were weather sealed. I tried 2 copies of the DA* 55mm before trying the Sigma. I still think about picking up a DA*55mm since I want a weather sealed lens and keeping both.

For me the Sigma bokeh is smoother and the subject is sharper. The HSM is faster to focus. I don't get the onion ring lights, or I couldn't find any images that showed them when I just looked. I typically shoot it at F/2 and I get very sharp subjects.

Some people in the thread have said they like the more "impressionist" bokeh of the DA* 55mm, to me it just looks harsh. I like the creamy melt-away bokeh of the Sigma. I am hoping Sigma updates its 50mm to the new Art series in the near future.

The bokeh of the DA*55 is only harsh (or impressionist ) wide open, from f1.8 (and certainly from 2.0) on it is pretty smooth in my experience. Still, for super-smooth bokeh fetishists, the Pentax 50/1.2 or FA 77/1.8 is probably a better choice.

[sTi]

UPDATE: the Sigma is front focusing bad on the k-30 had to adjust by 8 steps

The Sigma is known for its focus shift when stopping down, so the necessary adjustment will probably vary with the used aperture.

[snake]

Im watching this thread because i just got a Sigma 50mm f/1.4.
Sadly, I cant do a comparison with the Pentax lenses mentioned
At this point the only thing i can tell you for sure about the Sigma is......
ITS DARN HEAVY!!!
lifting my camera is like lifting weights now.

UPDATE: the Sigma is front focusing bad on the k-30 had to adjust by 8 steps

1. Don't watch this thread to tell you about the lens you have in your hands. USE IT.
2. 8 steps is not bad. That's why the adjustment is there. I'd say it was "bad" if your adjustment range was outside of what the camera allows.

[OldNoob]

1. Don't watch this thread to tell you about the lens you have in your hands. USE IT.
2. 8 steps is not bad. That's why the adjustment is there. I'd say it was "bad" if your adjustment range was outside of what the camera allows.

Good point. It was front focusing "Almost beyond correction"

[grahame]

Never tried Sigma 50/1.4, too big a standard prime for me. Here is my experience with pentax 50s:
I owned quite a few 50s primes, pentax or others. For AF lens, I bought an FA 50/1.4 before price rising (2007?), picked a better copy between two. So I think that copy is at least not a bad one, and I was very happy with it. Later I got a minty FA50/1.7, and found it is sharper than 50/1.4, both in center and corners. So I sold FA 1.4.
Earlier this years, I got a chance to play with DA55/1.4. Just from the camera LCD screen, I noticed it is better than F50/1.7. So I bought a DA55/1.4. Very happy. Sharper in center, much shaper in corners, even 1.6 on DA vs 2.0 on FA. And more important, DA's pictures is much more solid, much better CA control, and color is better.
True, AF could be faster. But the very long focus throw makes AF very accurate. The bokeh is busy, better when pass 2.0, but still not very good. And it makes high frequency noise when focus.
Best 50rish prime I have tried. And the FL of 55mm stays right between 43 and 77. 50mm is a little too close to 43mm if you have one.

[Ray Pulley]

I must be blind...I think that bokeh is pretty nervous looking instead of smooth

My thoughts exactly, plus lots of doughnut (rings) to boot.

I do own a copy of this lens, but I have not yet had the chance to use it much.

Ray

[Rondec]

The DA *55 is probably my favorite lens. I think a lot of it is the focal length. It lies between my FA 77 (which feels too long most of the time) and my FA 31 (which feels too short). I mainly shoot it at f2 and it just gives really good results. I don't shoot at f1.4 much because as others have said, the bokeh gets pretty nervous at that point, but as far as sharpness goes, it is usable there. The Sigma is a fine lens, but a little large for what it is.

[JJJPhoto]

I have to agree with Rondec's comments. The DA* 55mm is a fantastic lens. I wasn't a big fan of it when it first came out but the 55mm and 40mm pancake are my "go to" lenses for candid portraits (the 40mm just because it's basically a body cap with amazing optics so one is always on a camera body in my bags).

Even though I own the 31mm and the 77mm Limited primes (which render BEAUTIFUL portraits) the 55mm gets more use because the focal length on APS-C is "just right" for candid portraiture. Here are a few of my recent family snapshots with the 55mm:





I've owned a variety of Sigma lenses and most of them have been "nice" but none of them (except maybe the Sigma 14mm f/2.8 Aspherical) give me the kind of results I'm used to seeing out of the Pentax Limited and DA* primes. I've now sold most of my Sigma glass (except for the previously mentioned Sigma 14mm) and I'm not in a rush to pick up more.