I had to modify my version of Mark Tucker's plungercam to allow me to focus @ infinity without pushing the loupe into the mirror on it's way up. I added a Zeiss Distar diverging lens to accomplish this and had to elongate my duck tape "bellows". Now I can tilt the loupe lens more acutely to more accurately selectively focus my image. Sort of a cheap man's Zoerk multifocus thingie (check Zoerk.com)