I touched on filters for black and white photography in a prior post and since I've been talking about B&W, I figured I might as well touch base again. These colored glass filters are pretty essential to good black and white photography. Basically, they alter how much light of a certain color can pass through the lens and reach the film. Simply put, they make their complimentary colors darker on the print while making their own color lighter...a red filter makes reds lighter and blues and greens darker and so on, very useful in getting the most out of a scene. I could probably write a couple of pages on this process but, You get the picture. There are also some neutral density filters here, in a stack...they're for controlling overall brightness and come in different degrees of light and dark.