very sharp, great build and weather-sealing

price is too high, back-focus problems on the K10D (I guess on the K100Ds too) and the accuracy of the SDM system

Severe back-focus on my K10D and I don't understand why Pentax changed the (in my opinion great screw-motor) with the slower SDM, the image quality (manually focused because the SDM AF shows back-focus) is great by the way. I bought this DA* 55mm 1.4 especially the AF (already have the manual Zeiss Planar 50mm 1.4 and Takumar SMC 50mm 1.4)m I am very displeased with the AF accuracy.

Similar Products Used:

(manual focus only)
Planar 50mm 1.4
Takumar SMC 50mm 1.4

Tested on K20D:
Very good optics
tack sharp already at f1.4
no flare.

Strong ooF CAs
Very slow AF compared to my Canon stuff. Uuuh, ohhh ...
Rather harsh bokeh.

Heavy CAs, otherwise good, slow AF

Similar Products Used:

Canon 50/1.8
Canon 85/1.8
Pentax A50/1.2

Optically it is very good.
Compared to the FA50 contrast and sharpness are improved.
Bokeh is about the same, perhaps the DA is slightly smoother.
CAs are normal for this kind of lens.

The main disadvantage of the lens is that the autofocus is sloooow.
Compared to the FA85, which it should replace, the DA focusses about 3 times slower.
This is disapointing.
It is very difficult to follow playing children with this lens.
This lens is for static motives.

I have tested the lens.
Optically good, AF speed slow.

Similar Products Used:

Pentax FA50
Pentax FA85
Voigtlander Nocton 58mm