Sometimes you may have seen a hole which opens inside the camera lens when taking the photograph. The diameter of that hole called the "Aperture". we can control the size of the aperture using camera settings. The lens aperture is usually specified as an f-number (ex: f/2, f/3) the ratio of focal length to effective aperture diameter. Size of the aperture can change as numbers and that number settings in the range somewhere between 1.4 to 32 (Depends on your camera).
|Aperture photograph |
|Aperture photograph |
We can control two main things using aperture size. One is the density of the light that comes in to the camera body through the aperture at one time, using this you can make your object is bright or dim. Second thing is the "Field of depth" which means the background density or rather soft focus of the background. If you set the smaller aperture (f/16 to f/32) you can get photograph which has greater depth of field or rather very clear background with all in focus. If you set larger aperture (f/1.4 to f/8) you can get out of focused background with clear focus on your subject.
|Sample photograph to show out of focus background and focused subject |
(This photo has taken with aperture f/5.6, shutter speed 1/640s and ISO speed 100)
Shutter speed or rather exposure time is opening time of the shutter. Since we can control the speed of the shutter using camera settings, we can control the light which comes inside to the camera withing that "shutter speed" time period. For normal photography camera's shutter will stay open for about 1/250 th of a second. If the shutter stays open for 1/100 th of a second then more than twice as much light comes in. If the shutter stays open for 1/500 of a second only half as much light come in. Shutter speeds can be as fast as 1/8000 of a second (Depends on the camera).
|Sample photograph to show the difference of shutter speeds|
In photography term for this setting is called "Film speed". The meaning of the ISO is "International Organization for Standardization". The relationship of this setting to the photograph is if you are shooting in bright light you'll want a low ISO rating i.e. ISO-100. If you are shooting in low light, perhaps indoors or an evening setting, you'll want film with a high ISO rating i.e. ISO-1600.
So basically you can control the light (which comes inside to the camera through the aperture and shutter) using this ISO speed setting as well. But keep in mind high ISO speed means high noise.
So basically when you buying a camera check above three parameters. If the camera has wide range of options in each parameter, then it is a good camera. ex: Aperture 5.6-32, Max shutter speed 1/8000, ISO 100-3200.