How to Use the Aperture to Control Light in Photography

Besides changing the shutter speed to manipulate light as it enters the camera, you can adjust the aperture, the opening through which light enters the camera. Like an eye, the aperture expands or contracts according to how much light you want. The aperture is adjusted according to a scale of f-stops. The lower the f-stop, the wider the aperture opening and the more light is allowed in. An f-stop number is universal from one lens to another.

Difficulty: Moderately Challenging

Instructions

1. 
    

   Familiarize yourself with f-stop numbers. Commonly running between f/1.0 to f/64, f/1 allows in the most light. Each subsequent f-stop is half as fast as the previous one, which means that light flow is halved with each stop, allowing less and less light. Learn to "stop down."

2. 
    

   Bracket photographs. Record aperture setting and shutter speed for every picture you take. Take at least three pictures, one at a middle f-stop for the light you desire and one each at f-stop settings on either side. For example, if you use f/16, also take the same picture at f/11 and f/22. In this way, you will begin to get a sense of the way light is controlled by aperture settings.

3. 
    

   Use different lenses. As you use telephoto or wide angle lenses, you will learn that aperture is constant from one type of lens to another. A solid knowledge of f-stops translates to all lenses.

4. 
    

   Take pictures using every f-stop. The aperture setting affects a negative and its print. Write down the different ways the light affects subjects, as you manipulate light from stop to stop.

Resources

• What is an Aperture?
• Aperture Controls Light and Depth Of Field
• Aperture