The Exposure Triangle- The key to unlock your control over photography!

Exposure Triangle... Sounds too rhetoric, eh? Don't worry this isn't going to be a traditional lesson, even though its components sound so. I'll try to make these basic things easy and comprehensible, fun to understand... because knowing about exposure will change your view about photography. Taking a picture will never be the same again. ;) If you understand it, you will see a tremendous difference in the way you photograph, next time you pick a camera.

The Three Elements

Photo Credit: Valerie Hayken

Each of the three elements or components forming this triangle are related to light, and its interaction with the camera. Any change in one of them will impact the rest of the components. 

•  ISO: measure of camera's sensitivity to light
•  Aperture: the size of lens' opening when image is taken; it controls the amount of light entering
• Shutter Speed: the amount of time shutter stays open, or the speed with which the shutter open and close

To better make us clear, let us understand exposure through the most accounted but easy to remember example. 

The Window Metaphor

In many contents about photography you will find this example to illustrate the relation between ISO, Aperture and Shutter speed.

Imagine your camera is a window. It has shutters to open and shut.

Aperture is the window size. The more the window reveals, the more light enters the room and the brighter it gets.

The amount of time the window shutter remains open is shutter speed. The longer they are left open, the more light enters through the window.

Now imagine you are inside the room and wearing sunglasses when the window opens. This makes your eyes desensitized to the light that enters the room. This is what low ISO is!

I hope this picture helps bringing down the example on earth for you.

   Photo Credit: Emma Davies via Love Your Pics

So basically if you wish to increase the light in the room:

• You can keep the shutters open for longer time (drop the shutter speed)
• You can enlarge the size of window (increase aperture)
• or you take off your sunglasses ;) (i.e. increase the ISO)

With the advent of digital cameras in every hand, today it is very easy to experiment with these elements. This information is necessary to know your camera better, as today different shooting modes are available even in smartphones. It will be even more easier to grasp and experiment my previous blog about shooting modes in your camera.
To understand this concept in an illustration, you can check this demonstration. 

Those of you who are interested to read something serious about this topic should check out Understanding Exposure by Bryan Peterson, as reference. 

We will discuss each component in future posts with practical examples.