2 ExposureThe amount of light that is allowed to hit the film or the imaging chip in a digital camera
3 Three Things Control Exposure F-stop: Size of lens opening. Amount of light the camera allows in.Shutter speed. Length of time the light is allowed into the camera.Film Speed: Film sensitivity to lightYou can change any of these as long as you change the other
4 Exposure Measured in increments called stops Each whole stop is calculated in terms of halving and doublingIncreasing an exposure by one whole stop will double the original amount of light.Decreasing an exposure by one whole stop will cut the original amount of light in half.Each of the three variables of exposure, f-stops, shutter speeds, and film speed are all measured in stops.
5 StopF-stops, shutter speeds, and film speeds are ALL calculated in stops.There is one stop difference between:f/8 and f/111/60 and 1/125 of a secondISOs 200 and 400
6 Shutter SpeedLike f-stops, whole shutter speeds are spaced one stop apart.The longer the duration the more light that gets to the sensorThat means that a shutter speed of 1/60 lets in twice as much light as 1/125, and half as much as 1/30
9 Aperture and F-StopsLens opened up to f/2Lens stopped down to f/11
10 F-Stop A numerical representation of the diameter of a lens aperture. The “f” stands for the focal length of the lens in a fraction.The smaller the f-number, the bigger the aperture and the less depth of field.The bigger the f-number, the smaller the aperture and the greater depth of field.
11 F-Stops The f in f-stop refers to the focal length of a lens. The slash / indicates divisionThis means that an f-stop refers to the focal ratio.So in the case of f/8 on a 50 mm lens, it means 500mm is divided by 8=6.25mm, which is the physical diameter of aperture opening of f/8 in a 50mm lens.This works the same for all f-stops on all lenses.Lens opened up to f/2See more in sidebar of page 61Lens stopped down to f/11
12 F-StopsThe numbers are set up so there is a difference of one stop between each whole f-stop number in progression.Smaller numbers let in more light. Bigger numbers let in less.F/8 lets in twice as much light as f/11, and f/16 lets in half as much light as f/11Lens opened up to f/2Lens stopped down to f/11
13 F-Stops Each f-stop number indicates a standard amount of light so.. f/8 on a 24mm lens lets the same amount of light as f/8 on a 500 mm lens.
15 Depth of Field An important part of every image Refers to how much of the scene is in focus, both in front of and behind the subject or at whatever point the lens is focused.
16 Depth of Fieldf/2The smaller the aperture or opening, the larger the number of the f-stop and the greater the depth of field in the imageThe larger the aperture or opening, the smaller the number of the f-stop and the less depth of field in the imageCamera focused on the middle chess piece, the only object in focus with the f-stop of f/2f/22Camera focused on the middle chess piece, the only object in focus with the f-stop of f/2
17 Setting the Aperture Long Short Depth-of-Field Low F-stop High F-stop 3.2High F-stop16