What is ISO?

ISO is about the image sensor sensitivity to light in digital camera and film sensitivity to light in film based camera. So, the higher the ISO, the more sensitive the image sensor and the film is. And the more sensitive the image sensor and film is, the more likely of you to take pictures in low light condition.

Lower ISO number will give better quality pictures. This is because the higher ISO number you go, the more likely you will introduce noise to your picture. You just don’t want to ruin your ideal picture with something you can adjust.

Then, why do you need a higher ISO?

High ISO is usually needed when light is low or indoor photography. One of the examples when you need high ISO is when you are photographing your children blowing the candle in a dimmed environment.

Maybe you will think of using flash. But your subject might end up too white for the background. Unless you are using a DSLR camera which you can disperse your flash.

Have Fun in Photography,

Michael Wong. :-)