The filters I use only during the day when it is bright enough, with 4 sizes one is well served, they should not be used in conjunction with a ring flash but because the colors are distorted, but prefer to use spacer rings, even the slight warp on edge of the image is okay, if need may indeed be reworked. My Camera Canon 400 D can with all filters automatically focusing, but a small downer is there even when the lenses are screwed no longer fits the lens cap, because the lenses are actually only magnifying glasses are bulbous forward, that is, when not in use Unscrew again before the camera is put away, pity a customized cover the matter would certainly done no harm and would not have really driven the price upward. But on the whole I am quite at peace, price performance are OK.