[DaveHolmes]

Center focus and recompose is a sloppy technique,
use SEL and the four way controller.

For cameras such as K5, K20 or K-r (infact most DSLRs) with their visible AF points I would absolutely agree... For K-x users however, centre-point recompose is almost necessary even though it has 12 focus-points! (Infact I often wonder why it has 12 if you can only 'really' be sure where one of them is!)

[hoanpham]

My K20 is not good other than center focus point. I will try the K5 when it came back from service.
Looks like both Simon and Denis don't have any problem on K5 AF. You may not notice that when using SEL with the K5.

I am not looking for this lens until your report of Pentax' group meeting in Singapore.
That thread pulls the trigger. Thanks for sharing. Good lens indeed.

[JohnBee]

Oh, that's just great!
The last thing I needed was another lens I'll have to add to my kit.

Fantastic images btw.

[creampuff]

A quick snapshot of coffee at the airport before takeoff.
An example where the SEL button was used to set the point of focus away from center. Pentax K-r Sigma 30mm at f/2.2.

Processed the image with the new Lightroom 4 Beta. I've used every version of Lightroom but this one has more awesomeness than the current version 3.6. Love the selective WB correction feature that I've used here. The highlight and shadow recovery capability is also stunning. If you're serious about post processing, don't waste time with anything else, it's intuitive, simple to keep track of growing folders of images, easy to use plus the results are non-destructive and great. Download it and give it a go.

---

Last edited by creampuff; 01-12-2012 at 07:17 PM.

[bossa]

That system ... and using Live View (time permitting). LV is extremely accurate if you can take your time focusing. I was playing around with the Cosina 55/1.2 a couple of nights ago and even at f1.2 the LV gets close to 100% accuracy whereas using the OVF gets me significantly less.

Thanks, I'll give that a go.

[bossa]

A quick snapshot of coffee at the airport before takeoff.
An example where the SEL button was used to set the point of focus away from center. Pentax K-r Sigma 30mm at f/2.2.

Processed the image with the new Lightroom 4 Beta. I've used every version of Lightroom but this one has more awesomeness than the current version 3.6. Love the selective WB correction feature that I've used here. The highlight and shadow recovery capability is also stunning. If you're serious about post processing, don't waste time with anything else, it's intuitive, simple to keep track of growing folders of images, easy to use plus the results are non-destructive and great. Download it and give it a go.

The far side of the near cup's rim and the bottom of it's handle are in focus. Is that what you were looking for in this shot? I would have liked to see the swirls more IF myself.

I have found my Canon S screen (even though i butchered it installing it) works wonders for manually focusing faster lenses. And although the display is not super crisp, you can still see what's in and OOF pretty well. I have managed to get about 90% success rate with it and way better than Auto with it.

[creampuff]

The far side of the near cup's rim and the bottom of it's handle are in focus. Is that what you were looking for in this shot? I would have liked to see the swirls more IF myself.

I have found my Canon S screen (even though i butchered it installing it) works wonders for manually focusing faster lenses. And although the display is not super crisp, you can still see what's in and OOF pretty well. I have managed to get about 90% success rate with it and way better than Auto with it.

Yes, the focus point was on the far rim of the front cup. This was after all a quick snapshot. Aesthetically, it might have been better to focus on the leaf swirl but it would have thrown the background even more OOF and I would have needed to stop down a little more to control the amount of background blur. Also the camera angle to the subject is off.

This kinda shot shows up the one thing that would have made the Sigma even more perfect, reducing the existing minimum focusing distance of 0.4m. If it could focus a little closer like 0.3m, I'd seriously consider supplementing my do everything DA 35mm f/2.8 Macro Limited for all my close up working assignments. But I'll still keep the DA 35 Macro Limited because the color rendition is warmer than the cooler Sigma, the flat field focus and the bokeh from the nine aperture blades.

---

Last edited by creampuff; 01-12-2012 at 07:49 PM.

[bossa]

Yeah, I was wondering about field curvature when I mentioned that focus arrangement but it's probably just because of the wafer thin plane of focus combined with the angle of the shot. A smaller aperture would have prevented that a little I suppose. No criticism was meant though...

[cali92rs]

Some more Sigma 30mm fun...









BTW, that white spot is venus

[hoanpham]

Some samples, wide open.





Focus on center right edge (Asahi/pentax logo). First AF, then move camera 1-2cm to avoid field curvature:


Focus on upper left AF point (Asahi logo):

[jstevewhite]

Some samples, wide open.

I love the dreamy feeling this lens gives "kid shots" - pretty images of good lookin' kids there

[TOUGEFC]

Some samples, wide open.





Focus on center right edge (Asahi/pentax logo). First AF, then move camera 1-2cm to avoid field curvature:


Focus on upper left AF point (Asahi logo):

Nice shots mate

I love the dreamy feeling this lens gives "kid shots" - pretty images of good lookin' kids there

Where you been Steve? Having seen you on here for a while?

[jstevewhite]

Where you been Steve? Having seen you on here for a while?

Oh, you know - holiday, work, family stuff, real life, like that. Haven't taken nearly as many pix as I'd like to have done. But I do love that 30mm f1.4! How've you been?

[vrrattko]

Hi guys, excellent thread here.....lots of useful advices. I have one question - I know that sigma 30 is mostly portrait and street lens, however quite recently somebody uploaded full size photos from Yosemites taken with this lens - apparently stopped down and focused to infinity. It was taken with Olympus dSLR, so the image was a bit cropped...using only lenses sweet spot. All tests show weak corner performance, but i didn't see anything like that at those yosemite photos. Maybe that is not issue on 4/3, but only on APS-C. Would you mind somebody uploading some landscape shot, stopped down to 5.6 or 8 and focused on infinity. I'd really like to know if the bad corners on sigma are real issue or just another urban myth. Cheers....

[sheld]

Hi guys, excellent thread here.....lots of useful advices. I have one question - I know that sigma 30 is mostly portrait and street lens, however quite recently somebody uploaded full size photos from Yosemites taken with this lens - apparently stopped down and focused to infinity. It was taken with Olympus dSLR, so the image was a bit cropped...using only lenses sweet spot. All tests show weak corner performance, but i didn't see anything like that at those yosemite photos. Maybe that is not issue on 4/3, but only on APS-C. Would you mind somebody uploading some landscape shot, stopped down to 5.6 or 8 and focused on infinity. I'd really like to know if the bad corners on sigma are real issue or just another urban myth. Cheers....

Personally, I think its an urban myth, and I've posted on this before, https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/121684-thought...ml#post1784686. Its mostly a problem with field curvature, and absolute sharpness in the corners is actually quite good at F/8, and reasonable at F/2, especially when compared to fast zoom lenses at F/2.8. Unfortunately, I don't usually shoot the Sigma 30mm in better light, so all of the landscape examples I could find were examples I could find were at F/2, like this HDR tripod shot; 30mm Sigma, F/2, tripod, Pentax K-x; I wanted a short enough exposure so that the waves would not look like a total blur. Obviously, this is resized and sharpened for the web, and the image was at F/2, so the corners aren't nearly as good as they would be at F/8, but the corners are good enough for me.


I do have this test shot, at 30mm F/8 from my living room.


And here is a 1:1 crop straight from the camera, Pentax K-x bright settings, from the lower left corner of the F/8 photo. I'll try to take a real landscape shot focused at infinity, 30mm F/8 this evening.