Off-Camera Flash: How to Get the Right Flash Exposure

by Jim Zuckerman

off-camera-flash-Venice-Italy
Outdoors at Carnival
© Jim Zuckerman
All Rights Reserved
There are several issues that arise when you consider illuminating a subject with off-camera flash, and exposure is one of them.

Flash exposure intimidates pretty much everyone because it seems like it's so hard to predict and control. There are two aspects of exposure going on at the same time: the exposure from the flash on the foreground and the ambient light exposure on the foreground as well as the background. The truth is, these are very easy to manage.

There are two functions on our cameras that are used to deal with both aspects of exposure: 1) the exposure compensation feature (for ambient light), and 2) the flash exposure compensation feature (for the flash). If you don't know where these functions reside on your camera, it's time to find out. Check your manual. Every camera is different.

Here is the procedure I use when using off-camera flash such that I want to balance the lighting on the subject with the background as you can see in the outdoor shot (at right) and the interior photo of a model on a staircase in a palace below. When I say "balance the exposure," this doesn't necessarily imply that the foreground exposure is equal to the background exposure. In both of these pictures, you can see that the background is somewhat dark. This is what I wanted because that forces more attention on the subject, and it makes the subject more dramatic.

digital flash exposure
Carnival Model on Staircase
© Jim Zuckerman
All Rights Reserved
  1. I put the flash on ETTL (iTTL for Nikon users) and the camera on Program mode.

  2. I take a picture and then examine it on the LCD monitor on the back of the camera.

  3. If the ambient light is too light or too dark, I use the exposure compensation feature to make the adjustment. The light can be affected in 1/3 f/stop increments up or down.
If the flash exposure is not right, I use the flash exposure compensation feature to tweak that. This also works in 1/3 f/stop increments.

These functions - the exposure compensation feature and the flash exposure compensation feature -- work independently of each other. It's a simple matter of adjusting these controls to get what you want. Once you tweak the exposure, take another picture to see the results. If you need to make a further adjustment, do so and then shoot again.

In the past, professional photographers used Polaroid film to make test prints to judge exposure and lighting. Now, with digital cameras, we have the liquid crystal display (LCD) monitor to do the same thing. This takes the guesswork out of flash photography because you can see the results immediately.

Don't make the mistake of thinking experienced photographers don't need this kind of trial and error approach to flash photography, and that if you can't get it right the first time, you are not doing something right. Trust me - we have to do it exactly as you do.


digital flash exposure
Carnival, Venice, Italy
© Jim Zuckerman
All Rights Reserved

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