Aperture Vs. Shutter Priority

How to Use These Useful and Versatile Exposure Modes

by Peter K Burian

Shutter Motion
© Peter K Burian
All Rights Reserved

QUESTION: I want to get off shooting in the green AUTO mode but I find Manual mode too complicated; a lot of my photos are severely overexposed or underexposed. A friend recommended Aperture Priority and Shutter Priority modes. They sound good but can you explain how they work?

Answer from Peter K. Burian:
These two modes are very useful and versatile. They're the best options for greater control when you're ready to progress from fully automatic picture-taking. Here's how they work.

Shutter Priority (abbreviated as S or as Tv depending on the camera) is semi-automatic. This one allows you to set a desired shutter speed for motion control. The camera then sets a suitable aperture. For example, you might want to set 1/500 sec. to render a cyclist as "frozen" or 1/4 sec. to render a waterfall with an effect of fluid motion. (Naturally, you will need to use a tripod at such a long shutter speed to prevent blurring caused by camera shake.) If you decide to change the shutter speed, the photo will not get darker or brighter; the camera will change the aperture to maintain the same exposure.

Planes Depth of Field
© Peter K Burian
All Rights Reserved

SHUTTER MOTION (photo at upper right): Shutter Priority mode is ideal for use when your primary creative intention is the control of motion. For these photos, I used a slow shutter speed for blurring the motion and a 1/500 sec. shutter speed to freeze the motion. A +1 exposure compensation setting prevented underexposure. (c) 2013 Peter K. Burian

Aperture Priority (abbreviated as A or as Av depending on the camera) is also a semi-automatic mode. You set the desired aperture, such as f/22 for an extensive range of acceptably sharp focus (depth of field) or f/4 for a more blurred background. The camera then sets a suitable shutter speed. If you set a different aperture, the camera instantly changes the shutter speed to maintain the same exposure (image brightness).

PLANES DEPTH (photo at right): When depth of field -- the range of acceptably sharp focus from foreground to background is particularly important -- Aperture Priority mode is an ideal choice. For these photos, I used f/4 and f/22 in order to achieve entirely different effects. (c) 2012 Peter K. Burian

If you take a photo and it's too dark or too bright overall, you can modify the exposure using the camera's exposure compensation +/- control. Set +1 perhaps for a brighter photo and -1/2 (-0.5) when first experimenting with this feature. Then take the shot again. Later reset exposure compensation to zero when you no longer need it.

Hint: Although the exposure should be the same in any aperture or shutter speed with the semi-automatic modes, there is one important point to remember. If the camera produces blinking numerals in the viewfinder, it cannot provide a good exposure at the settings that you had made. (Most often the problem is caused by a high ISO setting on a bright day or a low ISO setting in a dark location when using Shutter Priority.)

In other respects, both of the semi-automatic modes are easy to use and they allow you to control the most important creative aspects in serious image-making.

Learn more about photography...

Peter Burian teaches three interactive online online courses at BetterPhoto's school of digital photography:

In addition, Peter's photography appears in two books co-authored by Jim Miotke and Kerry Drager: The BetterPhoto Guide to Creative Digital Photography and The BetterPhoto Guide to Photographing Light.

About Author Peter K Burian

Author: Peter K Burian

To learn more about photography, explore the photography classes offered here at BetterPhoto.