What is ISO? Sometimes it refers to the International Standard Organisation. But in photography, it’s an important setting related to the sensitivity of the film or sensor of your camera.
Definition of ISO
In the analog or film photography, ISO indicates the sensitivity of the film. The lesser sensitivity, the lesser is the noise. This way you could probably use 800 ISO film for the night shoot. For the bright day, something like 50 ISO is apt. When I was shooting, the most versatile was 200 ISO as it was possible to use it for the various light conditions.
In the digital cameras, it works in a similar way but it also indicates the sensitivity of the image sensor. And if you like to achieve the noiseless image for commercial usage, you may like to use ISO – 100.
How ISO works?
ISO is not the only setting which you can change to click the image in a poor light condition. It usually works along with the Settings of Shutter Speed and Aperture. The excessive noise created by the large ISO numbers sometimes can be reduced during post processing. But as a result, the image loses its sharpness. Concerning the fact that the image may lose its quality, it’s better to use other settings to create conditions for a better ISO numbers. However, if the light conditions during the focusing were not perfect, you may get an extra noise even with ISO 100. Surprisingly in this situation, you may need to change ISO for the higher number like 200.
It also important if your subject moves or you are shooting handheld. In such a situation, ISO is usually increased to get a sharp picture. Higher ISO numbers such as 600 or even 1600 (depends on the quality of your camera) are often used for street photography. However, basic DSLRs have smaller sensors so the amount of noise on 600 ISO may destroy the picture.
To decide what ISO range to be used, ask yourself the following questions:
- Is that enough of light?
- Do you like to have visible noise in your picture?
- Are you using the tripod or handheld?
- Is your subject static or moving?