Learning About Exposure

Exposure is the amount of light that creates your image. The main goal of each image you take is to use three key elements correctly to make a good exposure. The three elements are your aperture (f/stop), shutter speed and your ISO. 

• Aperture (f/stop) - This is the setting that tells you how much light will enter into your camera. This also changes your depth of field.

• Shutter Speed - This number indicates how quick or slow your shutter opens and closes to let in light. The faster the shutter speed, the sharper your image will be. A slow shutter speed can cause motion to blur, or show camera shake.

• ISO - is how sensitive your sensor is to light. The lower the ISO number, the sharper your image will look, but you will need a decent amount of light for a good exposure. The higher the ISO number, the more grain/noise you will notice (not as sharp) BUT this will allow you to take images in a darker setting.

The image on the left is definitely dark; this is called under-exposed. My shutter speed was too fast, and didn't let in enough light. The image on the right is over-exposed. This is when an image is too bright or 'washed out'. The white areas on the cake and the platter start losing detail from the image being too bright. On this image, I had my ISO a little too high and it let it more light than I needed. The middle image is an example of a good exposure!

On your camera's display screen and when looking through your viewfinder, you will see your exposure meter (see image below). Your camera will tell you when your settings will get a good exposure when the notches below the meter line up at the 0. When they fall to the left, or towards the (-) mark, that means your photo will be underexposed (too dark) and when they fall towards the (+) mark, your photo will be overexposed (too bright). Depending on your lighting situation, you might want your image a little brighter or darker than what your camera tells you. Use your exposure meter to help guide you as you change your settings!