Other than the hassle, is there any reason why placing a filter behind a lens wo uld result in poorer performance compared to placing the filter in front of the lens? I guess the image circle may be reduced more, but let's ignore image circ le issues for the purposes of this discussion.
Why don't manufacturers provide threads or an easy way to put on resin filters b ehind lenses? Heliopan makes an adapter that "clamps" on to lenses without thre ads, so filters or resin holders can be attached. Has anyone tried this? I tho ught that this was the main purpose for this adapter, but Bob Salomon tells me o therwise. Actually, Lee also makes a filter holder with two "rubber bands" for attachment.
Taping resin filters to the back of my lenses seems too dirty for me.