[davidmanze]

Hold it ;-) I will still do the MTFs - so a reversed front element isn't going to happen.

 
Are I see ...... I thought we were talking fifty as in millimetres focal length ..............

      I was in no way expecting you to test a reversed front lens element Klaus ....... (although it might have been amusing) ...... the MTF graph would have looked like a short spike in the center with no border readings at all, much less the corners ......

   however, there is something I find endearing about those Helios range of lenses ........ so, while we were both drawn to scratch our itches .......  I posted a couple of shots that I scratched earlier  !! .........