Please pardon my ignorance with this subject. LF is new to me and I just got a Gaoersi 4x5 "P&S" to complement my Chamonix 4x5 F1 (for long and night exposure). Anyway, I am trying to follow the instructions here: http://bhcamera.us/install-lens.php I am not sure exactly what I did, but currently the focus ring can be "taken off" the helical, i.e. it can rotate quite a bit without actually moving the helical focus. The infinity is also about 250 degrees away from the focus mark when the cone is at infinity. It's night now, and I can't check whether the infinity is correct now, but I needed to do something to move the infinity a wee bit. In the middle of the page referenced, supposedly one can loosen the retenting ring inside the lenscone by using a pair of scissor, but I cannot get it to budge. Appreciate any help you can give. Thanks.