i guy at a photo shop told me that i could make a 4 point star filter by using screen and a canning jar lid. he said that i could use some screen, from a window, or something else, and then get a lid that would fit around the outside of my lens. then he said to put some foam around the inside of the lid and screen, so that it would fit snug on my lens. has anyone heard of this or done this before? or maybe know of how to do this a better way? also what kind of screen could you use, metal or plastic, does it matter?