ISO - What does it mean to me?

One of the biggest questions I receive is "What does ISO mean and how do I apply it to my photography"? ISO stands for International Standards Organization, and it is a standardized industry scale for measuring sensitivity to light.

This is used in relation to how sensitive camera film is to light, or in the digital world the sensitivity of a digital image sensor. ISO is measured in numbers, with the lowest number being the least sensitive to light usually at the 50 to 100 range and the highest number being the most sensitive to light usually 3500 to 6400 range. Note: If you are shooting with an extremely expensive camera you might have lower/higher ranges available to you.

What do I mean by "sensitive" to light? Well if your camera is at 200 ISO it is not going to allow the sensor to "soak" in too much light. Otherwise you will have an 'over-exposed' image (those images that are almost or completely white). If it is set at 3200 ISO it is going to allow the sensor to "soak" in more light. Otherwise you will have an 'under-exposed' image (those ones that are almost or all completely dark) Generally in sunny, bright situations you will utilize a lower ISO (which also leads to much more detail in the image itself) since you don't want too much light to be absorbed. Whereas if you are in a night-time situation, or somewhere you can't use your flash indoors (church for example) you will want to 'jack-up' the ISO or absorb as much light as possible (which also leads to a grainy image)

Most digital cameras are set on "AUTO ISO" most of the time, meaning the camera itself determines how much light is the shot and how sensitive it has to be towards that light. Normally the camera is perfectly capable of determining this on its own but if you are noticing many blurry or really bright images most allow a control setting so you can change it. 


Of course if you really want to get artistic with your images you can up the ISO in a bright light situation to increase grain or lessen the ISO in a darker situation to create a blurred effect. So now that you have an understanding of what ISO means and how is applies to you go have some fun and create some unique images!!