i know how to adjust shutter speed on my cam. but i don't know how to adjust f-stop. i'll have to find my manual. thanks guys for your help!!!! i have a place to start!!!! Aperture: An opening in the lens that allows a specific amount of light to reach either the film or the CCD at the time of exposure. Almost all better quality lenses have and adjustable aperture setting that is calibrated in f-stop numbers. This in conjunction with the shutter speed and ISO rating of the film, or CCD form the basic controls that allow the photographer to control the exposure. the larger the number, the smaller the lens opening. Return to Top Aperture Priority: One of the automatic modes available on some cameras. When this mode is selected the shutter speed is changes to accommodate the aperture setting (f-stop) the user has chosen