I took the plung and decided to remove the front element of my Canon EF-S 17-55mm f/2.8 IS USM lens. This is a detailed video procedure for removing the front element and it even discusses calibrating the lens for any front/back focus issues. Please reference further discussion and details pertaining to this video at motleypixel.com PERFORM THIS PROCEDURE AT YOUR OWN RISK
Tags: canon, ef-s, 17-55mm, f2.8, is, usm, lens, dust, pump, cleaning, calibrating, front, back, focus, removing, element, fixing, repair, blowing, motleypixel, roy, niswanger, dirt, remove