Balancing Ambient Light with a Speedlite
Written by: Tiffany Joyce
Sometimes it is necessary to compensate for a background that is over-exposed, especially when shooting in bright light (as in outdoor photography). When using a speedlite as a fill flash, this is very easy to do. Different camera brands achieve this in different ways, so here is how to balance ambient light with light from the flash using a Nikon and a Canon.
When shooting with a Canon camera, turn on the High Speed Sync on the flash itself. Put the camera in Aperture Priority Mode (Av). Since Canon cameras have the ability to control background and foreground exposures separately using exposure compensation, simply dial down the exposure compensation in increments until the background light is at the desired level. The exposure of the flash and the exposure of the ambient light operate independently of one another, so the subject is consistently exposed while the background exposure adjusts up or down accordingly.
When shooting with a Nikon, go into the camera’s controls and turn on FP sync (Auto FP). In Nikon cameras changing the exposure compensation on the camera also changes it on the flash. So, you will need to shoot in Manual mode. Expose for the background by aiming the camera just past the subject to the background and pressing the shutter halfway to get an exposure reading from the camera’s meter. Set the aperture and shutter speed accordingly, take a shot, then adjust the shutter speed on the camera to change the exposure of the background. Increasing the shutter speed stops down the exposure, and decreasing the shutter speed stops up the exposure. Just remember that shutter speed controls ambient light and aperture controls the flash, and you will find extraordinary flexibility in controlling your photograph’s exposure.
This past weekend, I used my daughter as a model in order to demonstrate this concept for you all. We went out into the backyard at about 4:00 in the afternoon – it was about 110 degrees outside so we made it quick! I used my Canon EOS 7D and EF 50mm f1.4 lens (here is the equivalent Nikon 50mm f/1.4D AF Nikkor Lens), and attached my Canon Speedlite 580EX II Flash (here is the equivalent Nikon Speedlight).
This shot was taken at f/4.0, ISO 200, shutter speed 1/320, with no exposure compensation:
For this shot I kept the same aperture and ISO, but dialed down the exposure compensation by one stop, which set the shutter speed at 1/640:
For this shot I again kept the aperture and ISO the same, and dialed down the exposure compensation by two stops. This resulted in a shutter speed of 1/1250:
As you can see, the background in the first shot was somewhat overexposed, while the background in the third shot was somewhat underexposed. The middle shot, which was dialed down a full stop, seems to strike the right balance between the flash and the ambient light.
I love this handy little trick and I hope you find it to be useful in your own outdoor photography!
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