If you shine the laser into the center of the lens there will be a diffraction pattern of concentric circles that fall back on the Versalab face. The laser will be pointing parallel to the axis of the lens elements when the concentric circles form a bullseye.
Originally Posted by gamincurieux
Do you have the knob that holds the focusing helicoid tightened (#17)? Is there any wiggle or change in the lens alignment when spinning the fine-focus helicoid ring (#15)? Also, ring #18 that lets the lens rotate, is that tight?
Last edited by ic-racer; 01-02-2012 at 11:57 AM. Click to view previous post history.