F-stopPhotographyA ratio expressing aperture size; smaller numbers (f/1.8) mean larger openings that let in more light.Learn about this termUnit 03: exposure trianglePhotographyRelated TermsApertureThe size of the lens opening that controls how much light en...Depth of FieldThe range of distance that appears acceptably sharp in a pho...ExposureThe amount of light that reaches the camera sensor. Controll...