Samsung EVNX20ZZBSBUS ユーザーズマニュアル

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Concepts in Photography
Aperture
The aperture, a hole that controls the amount of light that enters the 
camera, is one of the three factors that determine the exposure. The 
aperture housing contains thin, metal plates that open and close to let 
light through the aperture and into the camera. The size of the aperture 
is closely related to the brightness of a photo: the larger the aperture, 
the brighter the photo; the smaller the aperture, the darker the photo.
Aperture sizes
Minimum aperture
Medium aperture 
Maximum aperture
Darker photo  
(aperture opened slightly)
Brighter photo  
(aperture opened wide)
The size of the aperture is represented by a value known as an 
“F-number.” The f-number represents the focal length divided by the 
diameter of the lens. For example, if a lens with a 50 mm focal length 
has an f-number of F2, the diameter of the aperture is 25 mm.  
(50 mm/25 mm=F2) The smaller the f-number, the greater the size of 
the aperture.
The opening in the aperture is described as the Exposure Value (EV). 
Increasing the Exposure Value (+1 EV) means the amount of light 
doubles. Decreasing the Exposure Value (-1 EV) means the amount of 
light halves. You can also use the exposure compensation feature to 
fine-tune the amount of light by subdividing exposure values into 1/2, 
1/3 EV, and so on.
+1 EV
F1.4
F2
F2.8
F4
F5.6
F8
-1 EV
Exposure Value Steps