Price paid 2017 -->39,20 euros
I didn't expect much about this lens, I bought it because I was so so so please with the 50mm 1.4, I started to get more auto revuenon. With that kind of brand it is like poker.
The lens

You can focus as close as 12 cm, Construction is mediocre, I don't like the feel, weight.
Central sharpness is good, corner are poor
Let's see on the field
SAMPLE 1
Center 100%
Left 100%
Right 100%
SAMPLE 2 on my dirty radio
Center 100%
SAMPLE 3
Center 100%
Left and Right 100%
Ok so you understand the poor corners now :-) no need for more corners 100% pics.
SAMPLE 4
Center 100% - not bad at all
SAMPLE 5 @ f4
Center 100%
SAMPLE 6 @ f8 - close focus
Center 100%
So now I see the strenght of this lens, the macro is nice, corner doesn't matter with that kind of shot.
SAMPLE 7 @ f4
100%
SAMPLE 8 @ f8
100%
f4 vs f8 - 100%
It is not razor sharp, it is sharp enough, make your own conclusion !
END OF TEST