I have the Canon EF-S 10-22mm and I'm going to purchase the Tiffen Variable Density filter. I only have 2 lenses right now the above and the 100mm macro. So I figured I'd get a 58mm-77mm step up ring so that I could use the filter on my 100mm lens. That got me to thinking. Should I pop the extra cash and get the 82mm VD filter and get a 77mm-82mm step up so that I avoid any possibility of vignetting? Is vignetting a problem with the 77mm VD filter and the 10-22mm lens? I would like to order tonight. Any help would be appreciated.