Purchase ground was once the continuous large aperture of 2.8. Provides in my opinion sufficient exemption for potential Portaits at 50mm.
Especially in this focal length range, the lens reproduces very well. Sharpness to the edge I find it very good at 2.8. Fade Out brings a bit more again. CA's are not a problem at 50mm.
In wide-angle, it does not look quite as good. At full aperture the sharpness in center OK, but towards the edge but it gets very soft and contrast. Fringing that is particularly strong here. Bothers me not because you can leave this out reckon yes. Fade help here very much. Landscapes or architectural photography succeed here with the shutter closed very well. Optical performance meets my requirements perfectly here.
Processing I regard as very valuable. It does not look cheap, the rings to adjust the focal length and focusing are rubberized and tacky. The lens hood is not the screamer. Looks a bit cheap, but a problem with loosening or falling off of the panel, I had but nicht.Der focus ring could run a little brisk, I find. A noise from the interior of the lens is normal. It appears this is to involve the image stabilizer. This works very well and is fortunately barely audible. The ultrasonic motor is also quiet and does its work very closely. Trouble focusing so far I could not identify. A direct intervention to focus in the AF operation is not possible.
I will continue to take pictures with this lens. It's fun and the value for money is, I think, an important factor contributing to the purchasing decision.
Summary:
+ Processing and handling (metal bayonet, high-quality plastic for housing)
+ Performance at full aperture 50mm
+ Volume Down OS (therefore useful for video)
+ Autofocus quietly and pleasantly fast
+ Price / Performance
+ - Lens hood
+ - Chromatic errors in the corners at wide angle
- Not really