Understanding ExposureUnderstanding Exposure

Why use different Why use different Shutter Speeds and Apertures.Shutter Speeds and Apertures.

All photos in this presentation were taken by and are ©Drew Loker, www.drewloker.com, unless otherwise noted. However, please feel free to distribute freely this presentation as long as the photo credits stay intact.

Grand Teton

Morning

Exposure

Setting the exposure is like filling a bucket:

How much you open the valve is going to determine how long it takes to fill.

Closing the aperture is going to make the exposure time longer.

The Camera is only as Smart as the Photographer

1/125 @ f/8 1/15 @ f/8

Left: Good sky Exposure. Right: Good Skins Tones…shirt blown out.

Except for the new SMART cameras…then it is as smart as the people in FRONT of the camera.

1/320 @ f/4.5 with fill flash

Here the camera balanced the background with enough fill flash to expose for the foreground.

Photo by Aimee Loker

Using Exposure Compensation

Program and Automatic Exposure Modes do a pretty good job when the subject is evenly lit. But when the subject is off center…or much darker/bright than the back ground, you have to use the Manual exposure mode…or dial +/- Exposure Compensation.

Using Exposure Compensation

But which is correct? Depends on what you are looking for? Maybe you want a silhouette.

Exposure Compensation is when you CHANGE the base exposure increasing or decreasing the total amount of light.

Equivalent Exposure (EE) is different than Exposure Compensation. EE is when you keep the SAME total amount of light…but change the variables to either stop or blur motion, or control your depth of field.

Using Equivalent Exposure

Using Equivalent Exposure

Long Exposures allow for creative control. Left: 4 sec exposure allowed for people to blur as the walked through the image. Right: 2 sec exp. Allowed for zooming while exposing.

4 sec @ f/10, 38mm 2.2 sec @ f/10, 112mm

Credits

• http://scphoto.com/Notes/Day_11/sld007.htm