Exposure Basics Introduction to Photography

What is Exposure  In photography, exposure is the total amount of light allowed to fall on the digital sensor while shooting a photograph.  Exposure is controlled by two parts: Aperture and Shutter Speed

Shutter Speed  Shutter speed is the amount of time the shutter is open and the camera’s sensor is exposed to light.  The faster it opens and closes the less light will be allowed in and the more the action will be frozen.

Shutter Speed cont’d  The slower the shutter opens and closes the more a moving object will be blurred.

Aperture  Aperture is that resizable opening the the cameras lens that allows light.  It works on exactly the same principles as your own eye’s iris.  When it needs more light it opens larger and when it it too bright it shrinks down.

Thinking About Exposure Think of exposing a photo the same way you think of filling a glass with water. Your goal is to fill the glass to the top without it spilling over. The faucet is the aperture. The more you open it the more water that comes out.

Thinking About Exposure cont’d The faster the water comes out the quicker the glass fills. If you leave the water running too long, you will overflow the water. Glass = Light Sensor Water = Light Faucet = Aperture Time = Shutter Speed

Thinking About Exposure cont’d

Exposure Cont’d Aperture

Exposure Cont’d  Shutter Speed

Aperture Vs. Shutter Speed

Different Settings

Changing the Settings  QUESTION:  If you know the perfect balance of shutter speed and aperture, why would you ever change the settings?  ANSWER:  Different settings will give you different results in your photos.

Motion Control  There are three ways you can control motion in your pictures  1) Frozen Motion  2) Blurred Motion  3) Panning Motion

Frozen Time

Blurred Action

Panning

Shutter Speed

Fast & Slow Shutter Speeds

Camera Shake Using too slow of shutter speed can often result in your photos being blurry from the movement of the camera. Use a support (tripod, monopod, or wall) to reduce the amount of camera shake.

Depth of Field  Depth of field is the distance that the camera focuses the image. Adjusting the aperture will change the DOF.  A “deep” depth of field will have a very large focal range. Everything from the closest subject to the horizon in the distance will all be in focus.  A “shallow” depth of field will have a very short focal range. The person you are taking a photo of will be in focus but everything in the background will be blurry.

Depth of Field

DOF & Aperture

Depth of Field Example

Exposure Chart