Quote Originally Posted by ruilourosa View Post

i asked beacause i heard that incresed spacing could benefit infinity sharpness at wide apertures!
It might. I've heard it was decreased spacing, though. It can't hurt to experiment, as long as you don't damage any threads or lose any spacers that might already be there.

Clarons are very sharp lenses and you'll be hard put to see any difference with standard film holders.