Has anyone attempted to use 58mm filters on the Olympus 12-40 PRO? I'm aware that it takes a 62mm filter, but I currently own a Panasonic 12-35 f/2.8 along with the 35-100 f/2.8, so I've accumulated a fair number of 58mm filters (variable ND, different strength ND, CPL, etc.). I'm interested in trading the 12-35 for the 12-40 for its stepless aperture in video as well as its manual focus clutch, but I don't want to have to go and buy a whole new series of filters. Looking at the 12-40, there is a fair amount of "real estate" between the outer edge of the element, and the filter threads, certainly a difference greater than 4mm in diameter. I am wondering if anyone has attempted to put a 62>58mm step-down ring on the 12-40 PRO and use filters on it? My main concern is vignetting at max aperture, so anyone that could chime in, it would be greatly appreciated. Thank you!