Quick Tip: Fill Flash For Contrast Control

Fill flash can be used for a quick fix for contrast problems that can be solved without further image processing. It is a powerful aid that can even trump today’s in-camera or post-process heightening of shadow detail. It can handle the problem with one exposure, and not rely on HDR or other curve adjustment tricks. Keep in mind that the sensor in your camera has a certain dynamic range that cannot be expanded even with such processing magic, and with too much work on the shadows some noise may creep in.

The fix, as shown here, is to make an exposure reading for the background or brighter light and then use flash to illuminate the shadows. The trick is to make sure the flash is not too apparent (though to the trained eye it may be noticed) and to use these occasions to produce contrast and color that is striking to the eye. Done right you can even saturate or darken the background more than it appeared, thus bring your main subject more into play.

Tools Used: Fill flash, exposure compensation, evaluative metering, Program Exposure mode, flash compensation (if necessary to soften the flash effect), exposure compensation control.

Image (#1) is a “straight” Evaluative/Program reading from the scene without flash. The metering system attempts to bridge the contrast gap and add some detail to the fairly prominent shadow areas. Overall the contrast is too high to be resolved in such a fashion and the sky and parts of the plant are washed out while the shadow details in the critical area of the flower are lost.

#1. (Left): #2. (Right)
All Photos © George Schaub

Image (#2) was created with fill flash with a –1 EV overall exposure compensation (which enriches the sky and darkens the leaves in the lower portion of the frame) and –1 EV flash exposure compensation, which diminishes the feel of flash use at this close range. Without flash this is like reading for just the highlights, which would have seriously underexposed the shadow areas. With just a touch of flash a balance is struck.

Settings: (non-flash) At ISO 160, f/11 at 1/80 second.

(flash) At ISO 160, f/11 at 1/160 second (-1 EV exposure compensation), -1 EV flash exposure compensation.

MicahB's picture

I will now be able to get a good shadow shot without the use of a high-end camera that could cost me a payday loan. Thanks for the tip and keep posting.