Flash Photography: Balancing with Ambient Light

by Jed Manwaring

Mexico friends (full flash w/bright ambient)
Mexico friends (full flash w/bright ambient)
© Jed Manwaring
All Rights Reserved
How often have you made pictures of people that end up looking like they're in a dark cave with no detail in the background?

Here's why: The default shutter speed for most flashes is 1/60th - 1/200th sec. when used in auto modes (P,A, or S). This is fine in a situation where the ambient or available light is bright enough that the camera will record background detail. However, it is too fast when the light is low.

For example, say the ambient exposure is 1/125 at f8. The background will be correctly exposed (the ambient light), and the flash will be in balance with that light (see Mexico Friends image). But if the ambient exposure is 1/15 at f8, and your camera defaults to 1/60th or 1/125th in this mode, then your background will be very dark.

For More Pleasing Flash Shots:

Higher ISO: One easy method is to use higher speed film, or on digital cameras, set the ISO to be higher. This will allow you to pick up more background light.

Slow Down the Shutter Speed: Use Shutter Priority (S or Tv) to control the shutter speed. While some cameras default to a 1/60th or higher shutter speed, others allow you to set a slower shutter speed (often called "slow sync"). Start with your default shutter speed, and dial in a slower shutter speed, and you will pick up more ambient light with each step down in shutter speed.

Note: You can use Aperture Priority (A) to control the shutter speed, but this will change your depth of field, so what is in focus might also change.

Article by Jed Manwaring. To learn more about photography, explore the many online photography and Photoshop classes offered here at BetterPhoto.com.