ISO
Ξ May 7th, 2008 | → 1 Comments |
∇ Photo | ∇ Definition, ISO, Photography, Rule of Thumb |
The acronym ISO stands for a lot of different things, but for this post ISO will be used to define Film Speed, as it is known in Photography.
Film speed describes the index of sensitivity of the film used by analogical cameras, and is also used describe the speed of light capture in most common digital cameras.
A film may have a low ISO index (called slow film) meaning that it is less sensitive, and thus, needing more time of exposure. On the other side, a high ISO index film (called fast film) is very sensitive needing less time of exposure.
Another thing to consider is that using a fast film your photos will seem to be more grainy. So I try to use the lowest ISO possible. As a rule of thumb: use ISO from 80 to 200, for sunny days outdoor photos; ISO 400 for usual indoor/shady photography; anything higher, from 800 to 1600 is used only if the lighting conditions make it necessary.
In practical terms, try the film speed simulator available here, and see for yourself the differences between using different levels of film sensitivity.
