Several posts on this forum have mentioned the Cokin P series line, especially for GNDs (the main reason I'm planning to purchase a Cokin filter). However, I was looking up the specs and it appears the Cokin A series is the appropriate size given the format of the micro 4/3 system. According to the Cokin website, the A series is "recommended for lenses between 36 and 62mm in diameter with a focal length over 35mm". Now, I do have a 14-150mm lens (58mm filter thread) and am considering picking up the 9-18mm (52mm filter thread). Would the A series produce vignetting or other issues with these lenses? Or, if all I care about are the "sunset" and GND filters, should I just buy those and hold them over the lens for the exposure? I assume "filter shake" isn't as much of an issue as camera shake?