Often, we do not pay attention to the ISO settings of a camera, which is in fact very important. If one gives enough attention to this feature of the camera, we can take quality pictures. The ISO setting is related to the sensitivity of a digital camera to light. The higher the ISO, the more sensitive it is to light.
basic fact is that the lens aperture, shutter speed and ISO form the
‘exposure triangle’ for good photography. For instance, if you
want to use a faster shutter speed without changing the aperture, you
could increase the ISO instead.
needs to be understood that when the ISO setting is increased, the
light values from the subject become higher. However, the higher the
ISO value, the worse the noise. Therefore, for good pictures ISO
adjustments are best kept for situations where they are absolutely
necessary. One should think about the ISO if the light levels fall to
the point where you ‘run out of apertures’ and a slight camera
shake can spoil the picture.
should increase the ISO if you’re shooting in marginal conditions.
Just remember that when light is strong, keep the ISO setting as low
as permissible. When there is very less light like candle light or
twilight, keep the ISO high but use a tripod or firm rest with a
cable release or time release for shutter opening of the camera.
example, when the light is harsh and you wish to take a land scape,
use IS0 setting from 50 to 100. And, for daytime outdoor sports set
the ISO value at 200. For astro-photography, keep the highest range
of ISO values and camera should be mounted on tripod.
higher values of ISO setting in dim light without camera shake, will
give you clear image but with some background noise.