Aster be a lens test

This is a test shot of my 'new' Auto Chinon MC 1:1.7 50mm. It arrived with a loose DoF ring but after some trepidation I've repaired it (I now know how to get these lenses apart and the low cost meant it worth the try !)

This was taken at full 1.7 hand held and as(in a hurry) I forgot to change the K-r to MF it was on AF on Av. The benefit I found was that I got a 'bleep' when it was focussed (I didn't know it would do this ? Is this 'Catch in focus' ?).
Check the purple bloom near the centre, as It was on centre point AF.

NOTE: This is the untouched jpeg straight from the K-r, no colour/brightness correction or sharpening etc !

All comments welcome !
Peter