[DSims]

I'll be damned, people Like Sigma's rendering?!

Ha Ha - maybe they simply put up with it or don't notice, but it's an impressive performer otherwise.

[Stavri]

Ha Ha - maybe they simply put up with it or don't notice, but it's an impressive performer otherwise.

As far as third party lenses go, Tamron's SP coating is superior in my opinion. I'd even give the edge to the Samyang/Rokinon UMC coating over Sigma's

[Canada_Rockies]

I am a DA 12-24 fan. There are some shots on my Flickr site.

[mconwxdr]

I went through a similar mini-panic attack with my DA15. I noticed softness on the edges through f9. But then I realized if you focus just a little in from infinity it improves a lot. There are a bunch of posts on here about it's field curvature and why you don't want to focus near the hyper-focal distance with this lens when you want edge-to-edge sharpness. Those eased my worries a lot. Plus I went through my old shots and saw how awesome it renders. Whenever I get the itch to try a different UWA that squashes it in a hurry.

[ChristianRock]

The Samyang/Rokinon 16mm f2 is probably going to be my next lens, budget permitting. So if you didn't click with the DA 15, you might want to check it out. Small it isn't, and it's manual focus, but the price is right and it can be sharp down to the borders by f4, according to the tests.
If you don't like it, you can sell it for hardly any loss, and try the DA 15 again...

[bpv_UW]

Thanks all for the great input.

What about the 12-24? I thought it was a stellar performance across the board (that is from memory and I could be totally wrong!).

The sigma 8-16mm f/4.5-5-6 is sharp across the frame - much better than the DA15. But there are some drawbacks to using that lens.

The more gear I've tried the more I've found the compactness matters, which is a strike against both of these lenses for me. I also tend to use a CPL a fair bit, even on wide lenses (yes, it sometimes generates funny skies due to the wide field of view, but sometimes that trade-off is worth it IMHO for the effect it has on the foreground/midground). So that's another strike against the Sigma (as well as the Samyang 14). I've thought a lot about all of those lenses, but ultimately I don't think the trade-offs are worth it for me.

Although it's not supposed to be much different, why don't you try a new HD 15 this time? They just went on sale, you can pick black or silver, and you can send it back within 30 days if it doesn't move you.

Good point, may try this.

Are you peeping just for the sake of peeping, or do you need the border performance for any other reason(s)? If just for peepings sake, then encouraging you to stop peeping so much, or to at least stop letting it slow you down is the best path to persuading you imho. That and considering the trade-offs that Digitalis alluded to... I could be wrong (because I am one of those who has chosen to allow the DA15 to control my mind) but to achieve the border performance at the wide angle of view you desire while maintaining or improving the other levels of performance and quality, you're going to be paying for it with weight, size, and expense. If those factors don't matter to you, then maybe you want to look at the 645Z and a nice WA lens for it. (Download this image and give it a peep!)

I'd like to be able to make some large prints for my house, and eventually maybe casually sell an image or two, though it'll always just be mainly a hobby to me. That said, in part, I'm just peeping to peep...can't fight that piece of my nature, I guess. I hear you that to get performance on will have to sacrifice size/weight and/or expenses (likely both). I don't want to sacrifice size/weight to a huge degree, but am fairly flexible on price (though not infinitely; a medium format system is definitely out of my reach...and way too much camera for me anyway).

Could you please link one or two examples full res prefferably - so we could pixel peep too ?? I'd think that DA 15 is very well regarded and was myself looking into that direction. Would be nice to see some full res images of low corner sharpness for the reference purposes - because what I saw so far (in rescaled version - I admit that ) - was only short of pure awesomeness - please upload something at f8 or f11 max - other than that I think diffraction is crippling any lens on digital crop camera.

Here's a shot at f/11, 1/45s, handheld, K5. If you compare center with borders in the background (mountains/houses), midground (flowers), or foreground (flowers, grass) you can see a clear difference in resolution (softer/muddier details at/near the borders). This is most noticeable in the background and midground, but still noticeable in the immediate foreground as well.

https://www.flickr.com/photos/bpverdoorn/15097009197/sizes/o/

I went through a similar mini-panic attack with my DA15. I noticed softness on the edges through f9. But then I realized if you focus just a little in from infinity it improves a lot. There are a bunch of posts on here about it's field curvature and why you don't want to focus near the hyper-focal distance with this lens when you want edge-to-edge sharpness. Those eased my worries a lot. Plus I went through my old shots and saw how awesome it renders. Whenever I get the itch to try a different UWA that squashes it in a hurry.

I'm aware of the field curvature issue, but touche. I'm sure there are times (perhaps lots of times) when I need to be more careful with focusing.


-Brandon

[manntax]

Here's a shot at f/11, 1/45s, handheld, K5. If you compare center with borders in the background (mountains/houses), midground (flowers), or foreground (flowers, grass) you can see a clear difference in resolution (softer/muddier details at/near the borders). This is most noticeable in the background and midground, but still noticeable in the immediate foreground as well. https://www.flickr.com/photos/bpverdoorn/15097009197/sizes/o/

OK, firstly that's a terrific shot you got there I checked the sharpness and indeed the shot looks softer in distant mountains and trees - BUT , I personally think that your shot is not focused properly for a hyper-focal distance ( it is focused too close ). You should focus a bit further away , instead you get what you have here - fairly sharp and crisp foreground ( it could be improved even further with some extra PP ) and soft-ish far distance. However, when I look at the foreground belt , which is sharpest , I clearly can see the difference between borders and central part of the photo - in the centre the grass looks nice and crisp, and becomes slightly less and less clear towards the edges ( both bottom corners of the shot ).

But the reason your shot is not sharper at the far distance is that you focused too close to achieve uniform sharpness across this huge area. In this situation (and so gorgeous view !) I would have gone for MANUAL focusing with double-triple checking where my sharpness goes. In your case , the focal point was too close, probably just few feet away from the camera , and so the lens produced sharp immediate foreground with gradually reducing sharpness towards the far distance. I do not know how this lens focuses , but from my manual experience with Tokina 17mm there is a point at which pretty much everything is in sharp focus - here is an example ( click for full 16PM size ) - the shot is from K-01 , F8 , 1/250th , ISO 100 ( shot has nothing to do with a good landscape - it was just my son running towards me ,and I found it hilarious how tiny he was in comparison to the whole frame :P )
- personally think that detail in this photo is amazing - one can clearly distinguish the furtherst details , or face and clothing of my boy - check the full size. Now, judging by what I've seen online so far - I think that DA 15 is capable of producing equally or sharper images - all depends on how it is focuses - so your own advice :

I'm sure there are times (perhaps lots of times) when I need to be more careful with focusing.

may well be all that you really need

---

Last edited by manntax; 09-19-2014 at 01:10 AM. Reason: broken link

[kp0c]

Originally posted by kp0c
What about the 12-24? I thought it was a stellar performance across the board (that is from memory and I could be totally wrong!).
Originally posted by Digitalis
The sigma 8-16mm f/4.5-5-6 is sharp across the frame - much better than the DA15. But there are some drawbacks to using that lens.
The more gear I've tried the more I've found the compactness matters, which is a strike against both of these lenses for me. I also tend to use a CPL a fair bit, even on wide lenses (yes, it sometimes generates funny skies due to the wide field of view, but sometimes that trade-off is worth it IMHO for the effect it has on the foreground/midground). So that's another strike against the Sigma (as well as the Samyang 14). I've thought a lot about all of those lenses, but ultimately I don't think the trade-offs are worth it for me.

I'm a little confused. You said in your first post that you are "now contemplating a move to another system" because the 15mm was not what you were hoping it was. That is obviously fine, you can change system if you believe it will give you better result. However, you then say size does matter a lot for you - so much that the 12-24mm cannot be an option. Thus, I don't understand what other system would give you a better performance than the DA 15mm while being as light and small. What system are you most interest in out of curiosity (genuine question, I don't know much about other system and their UWA offering).

[lytrytyr]

The Samyang/Rokinon 16mm f2 is probably going to be my next lens, budget permitting. So if you didn't click with the DA 15, you might want to check it out. Small it isn't, and it's manual focus, but the price is right and it can be sharp down to the borders by f4, according to the tests.

But there's a catch with the Samyang wide primes
(and a lot of the new mirrorless wide angles).

Their edge resolution looks good on the geeky tests,
but their geometric distortion barely qualifies them as "rectilinear".
Then, when you correct the distortion by moving pixels around,
you end up lowering the edge resolution anyway.

In the DA 15, Pentax chose a specific distortion/resolution tradeoff,
along with the limitations of a compact design.

[ChristianRock]

But there's a catch with the Samyang wide primes
(and a lot of the new mirrorless wide angles).

Their edge resolution looks good on the geeky tests,
but their geometric distortion barely qualifies them as "rectilinear".
Then, when you correct the distortion by moving pixels around,
you end up lowering the edge resolution anyway.

In the DA 15, Pentax chose a specific distortion/resolution tradeoff,
along with the limitations of a compact design.

As far as I know, the distortion of the Samyang 16mm f2 was classified as "very low for its class" - just over 2%. Which is more than the DA 15 which is at about 1.4%. The Samyang 14mm f2.8, on the other hand, is more like what you describe, I think - on full frame. On APS-C it's not quite as bad... but still much worse than these other two at about 5%.

Or is there more to this that I don't know? That's possible...

[lytrytyr]

As far as I know, the distortion of the Samyang 16mm f2 was classified as "very low for its class" - just over 2%. Which is more than the DA 15 which is at about 1.4%.

At 2.5%, the Samyang 16/2.8 is on a par with the good old Pentax 16-45 at 16mm.

[bpv_UW]

I'm a little confused. You said in your first post that you are "now contemplating a move to another system" because the 15mm was not what you were hoping it was. That is obviously fine, you can change system if you believe it will give you better result. However, you then say size does matter a lot for you - so much that the 12-24mm cannot be an option. Thus, I don't understand what other system would give you a better performance than the DA 15mm while being as light and small. What system are you most interest in out of curiosity (genuine question, I don't know much about other system and their UWA offering).

That makes 2 of us

I've contemplated Nikon (either D7100 or D600/610), but recently rented a D7100 and several lenses and ultimately decided the size sacrifice was just too great. I'm now primarily considering staying with Pentax or going to a mirrorless system (most likely Sony a7; though the Fujifilm XT-1 and some of the better native primes for that system are tempting in some ways, but I would really like the resolution of a good 24 mp sensor, the Fuji is only a 16).

---------- Post added 09-19-2014 at 10:24 PM ----------

here is an example ( click for full 16PM size ) - the shot is from K-01 , F8 , 1/250th , ISO 100 ( shot has nothing to do with a good landscape - it was just my son running towards me ,and I found it hilarious how tiny he was in comparison to the whole frame :P )
- personally think that detail in this photo is amazing - one can clearly distinguish the furtherst details , or face and clothing of my boy - check the full size. Now, judging by what I've seen online so far - I think that DA 15 is capable of producing equally or sharper images - all depends on how it is focuses - so your own advice :

Agreed there is overall impressive detail in this photo. One can see a little fall-off in resolution at the borders in the background (the trees), but not much. A difference between this photo and the one I posted is that the required DOF in my scene was much greater (the flowers were much closer to the front element than the grass in the foreground in your image), thus easier in your shot to find a proper focus point that will lead to foreground and background being sharp. I think you're right that my focus point was too close to the camera in my shot, but I'm not sure that choosing a more distant focus point wouldn't have led to noticeable drop off in resolution in the immediate foreground flowers. Who knows? I think at times I may expect too much in terms of DOF; focus-stacking would be a solution.

-Brandon

[Rondec]

That makes 2 of us

I've contemplated Nikon (either D7100 or D600/610), but recently rented a D7100 and several lenses and ultimately decided the size sacrifice was just too great. I'm now primarily considering staying with Pentax or going to a mirrorless system (most likely Sony a7; though the Fujifilm XT-1 and some of the better native primes for that system are tempting in some ways, but I would really like the resolution of a good 24 mp sensor, the Fuji is only a 16).

---------- Post added 09-19-2014 at 10:24 PM ----------




Agreed there is overall impressive detail in this photo. One can see a little fall-off in resolution at the borders in the background (the trees), but not much. A difference between this photo and the one I posted is that the required DOF in my scene was much greater (the flowers were much closer to the front element than the grass in the foreground in your image), thus easier in your shot to find a proper focus point that will lead to foreground and background being sharp. I think you're right that my focus point was too close to the camera in my shot, but I'm not sure that choosing a more distant focus point wouldn't have led to noticeable drop off in resolution in the immediate foreground flowers. Who knows? I think at times I may expect too much in terms of DOF; focus-stacking would be a solution.

-Brandon

I think focus stacking is probably about the only option -- or just stopping down past the diffraction point. It is really tough to get "everything" in focus without having some softening from being at f16 and diffraction setting in. Better to stay at f8 and do some focus bracketing.

[Canada_Rockies]

There is an app for phones "TrueDOF" that displays the depth of field for any lens on any format. It's inexpensive and easy to use. It also has some sort of way that it will not display past the diffraction limit so you have to guess beyond that f/stop.