Samsung Galaxy NX500 Camera User Manual (en)

Concepts in Photography

How the aperture setting, shutter speed, 
and ISO sensitivity control exposure

The aperture setting, shutter speed, and ISO sensitivity are closely 
interconnected in photography. The aperture setting controls the opening 
that regulates the light that enters the camera, while the shutter speed 
determines the length of time that light is allowed to enter. ISO sensitivity 
determines the speed at which the film or digital image sensor reacts 
to light. Together, these three aspects are described as the triangle of 
exposure.

A change in shutter speed, aperture value, or ISO sensitivity can be offset 
by adjustments to the others to maintain the amount of light. The results, 
however, change according to the settings. For example, shutter speed is 
useful in expressing movement, aperture can control the depth of field, 
and ISO sensitivity can control the graininess of a photo.

Wide aperture  
= more light
Narrow aperture  
= less light

Wide = shallow depth of field  
Narrow = deep depth of field

Fast speed  
= less light
Slow speed  
= more light

Fast = still  
Slow = blurry

High sensitivity  
= more sensitive to light
Low sensitivity  
= less sensitive to light

High = more grainy  
Low = less grainy