I'm still a beginner in photography, but
Comparing the pictures of my EF-S 18-55mm (with
a focal length and a similar opening), I must say
this is much better optical quality.
Good image sharpness compared to 18-55.
The distortion is visible to 10mm but this is not
surprising for such a wide angle!
Focusing possible only 24cm, very
significant to exaggerate the proportion of a
foreground object.