[northcoastgreg]

And yet, despite the soft corners, the DA15 manages to lead the "greatest Pentax lens ever" tournament, relegating the FA31 to second place. It's my favourite lens too, because of the colours, contrast, compactness and build quality.

Exactly. In the end, it's always about the images, and the fact is, corner to corner resolution is not as important as it is often made out to be. I've taken thousands of images with my DA 15, and there's only been three or four times where I've regretted that the lens wasn't sharper toward the edges. In practical use, it turns out that "soft" corners are rarely much of an issue. Hardly anyone, when viewing an image, looks at the corners. But they will always notice the colors and the contrast. I have other lenses that are sharper in the corners but don't have the contrast or the colors of the DA 15, and I find myself less satisfied with images from those lenses than with images from the DA 15. I rarely miss corner resolution, but always miss better color and contrast.

[emalvick]

I've purchased a DA 15 as a potential replacement or supplement to my Tamron 10-24, which slightly lacks and is a bit large.

My own thought is that at 15 mm, I'm generally not that concerned by the corners. My images cover a wide expanse that I can generally live with a bit of lack of sharpness at the corners. If it was a portrait lens, I might have concern, but I don't. I know there are complaints that it could be faster, but I'm generally shooting landscapes at that focal length, so I'm rarely wanting to shoot at anything more open than f8.

Anyway, I like the lens a lot, but I definitely need special reasons to shoot it. I would not vote it my favorite lens, but it's because I like other focal lengths better.

[KDAFA]

Exactly. In the end, it's always about the images, and the fact is, corner to corner resolution is not as important as it is often made out to be. I've taken thousands of images with my DA 15, and there's only been three or four times where I've regretted that the lens wasn't sharper toward the edges. In practical use, it turns out that "soft" corners are rarely much of an issue. Hardly anyone, when viewing an image, looks at the corners. But they will always notice the colors and the contrast. I have other lenses that are sharper in the corners but don't have the contrast or the colors of the DA 15, and I find myself less satisfied with images from those lenses than with images from the DA 15. I rarely miss corner resolution, but always miss better color and contrast.

Although off-topic, allow me to say that a similar situation exists with the FA43 Limited f1.9. Every now and then you'll hear it said that it isn't sharp in the corners wide open (f1.9). Personally I've never understood the concern in practical usage; at that large an aperture I'm looking for shallow DOF, eg. in portraiture, to blur out the background - no worries with corner sharpness there. Or again, who would shoot landscapes or architectural work at large apertures? And like the DA15 Ltd, the 43 is a lens that utterly excels at colour and contrast, with magical rendering when done right. Never found the corners issue relevant in use.