Photography Exposure

Understanding and getting photography exposure correct is essential to taking great photos. Think of exposure as a container such as a bucket that needs to be filled to the top with water. If you only fill the container three quarters full it is under full or under exposed. If you put too much water into it the water will spill over the top and the container will be over full or over exposed. If you correctly fill the container to the top it will be properly full or properly exposed. 
Photography exposure determines how light or dark your photo will appear once it has been captured by your camera. If you over expose a photo it will appear too bright and finer details pf the photo will be lost. Similarly if you under expose a photo it will appear too dark and again the finer details will be lost. Get it right and you have the chance to take a great photo.

Photography exposure and  automatic mode

Don't just rely on your cameras automatic mode for photography exposure. While it is true that the sensor inside your camera will serve you well most of the time there will be times when it can be fooled. Your camera's sensor works by averaging out the light and dark areas of your potential photo and may struggle with deep contrasts, For example, a bright sky over a dark landscape. It is best to learn how to control exposure by using the three elements that effect it, They are aperture value, shutter speed and ISO settings.

Elements of photography exposrue

The three controlling exposure elements and your photos characteristics that they effect

the elements of exposure triangle
It doesn't matter how you reach the correct exposure value for your photo. You can flood the camera sensor for a brief moment, trickle light in over a prolonged period or even adjust the sensitivity of your cameras sensor to effectively reduce or enlarge the size of the container or bucket you need to fill.
This is great news for photographers giving us more control over our photos in situations where we need it.
For example, if you want to photograph a fast moving car you would choose a fast shutter speed to minimise the cars movement while the photo is being taken. Doing this would keep the image of the car sharp but the photo would in all probability be under exposed. This is because your camera only has a very brief moment to capture enough of the light required to correctly expose the shot. You would then compensate for this by selecting a larger aperture (smaller f stop number) to allow a greater amount of light to pass through the camera lens in the time that the shutter stays open.
The important thing to remember is that there are many different combinations of ways to create the exposure that you require for your photo. Each combination though will effect your photo in different ways as listed below and will result in very different photos. 
  • The aperture value you chose will affect the photos  depth of field .
  • The Shutter speed you choose will affect the photos  motion blur .
  • The ISO value you chose will affect the amount of  noise in photos .

Your camera is a very intricate piece of equipment so take the time to play around and experiment with its settings. Master the art of exposure and you will be well on your way to knowing how to take good photos.