What is ISO?

ISO controls the amount of light your camera lets in, and therefore how light or dark photos turn out to be. The ‘base’ value of ISO is typically around 100, usually used for sunny outdoor photos or high lighting shoots. For darker / low lighting shoots, ISO 1600 or above is best.

If the ISO is too low – such as the ISO 200 image below – photos can come out too dark or blurry. If the ISO is too high – such as the ISO 6400 image below – photos can turn out grainy or noisy.

Noise

Visual ‘noise’ by definition is ‘excessive and irrelevant visual information that can distract, confuse, or overwhelm an observer’. In photography it usually takes the form of grain.

Experimenting with ISO

To experiment with ISO, I took a camera and chose a few subjects to photograph. I found I got the best results (of differences between the ISO settings) in a dark room photographing an LED music deck.

I held the camera in the same position and repeated the same shot using a range of ISO settings, and these were my results.