Originally posted by jake123 The Sigma 50mm would be my choice at a lower price with much smoother bokeh.
Well, the Sigma is (only) 13% cheaper (in EU). My main concerns with the Sigma are that is is bulky and that I am concerned how precisely the AF would nail focus.
Has anybody heard about AF precision with DA*55 vs. Sigma50?
Originally posted by RaduA you're wrong and this puppy will have both better and more even resolution than Sigma
I hope so
Originally posted by TKH The mistakes I make with my camera and the DA*55 are greater than the mistakes the lens makes
Maybe, you didn't nail the focus and RaduA is correct. As I said, I hope so.
Originally posted by blende8 Judging bokeh can only be done in comparison with other lenses and this in a controlled environment (tripod ...)
This is only partly true. If you can see a point light source out of focus, you actually can see the defocus PSF. The standard PSF looks like a bright disk with a sharp border. Lenses optimized for great bokeh tend to have a PSF with a somewhat brighter center and a somewhat softer edge, while being perfectly round.
UPDATE:
Some of the DA*55 images actually showcase its PSF. I have cropped the PSF from two of the photos in this thread, and a PSF from photozone's test of the Sigma 50. On the attached image, the left two snippets are from the DA*55 while the right snippet is Sigma 50. All at f/1.4.
It definitely has a dimmer center and quite hard edges. Sometimes, the edge doesn't appear as hard as other times (cf. left and middle center). Nevertheless, a clear tendency to circular rather than disk like PSF.
The Sigma 50 shows signs of an onion-like PSF. Which is criticized as well (only at f/1.4). In comparison, the Pentax PSF is smoother in the inner part but has a much harder border. I think there is enough evidence to be at least concerned about the DA*55 bokeh.