Balancing Flash and Ambient Light by Charles Glatzer

Image by Charles Glatzer

Image by Charles Glatzer

Text and photographs by Charles Glatzer

When I hear someone say, “I hate flash images,” it typically tells me they feel uncomfortable or do not fully comprehend how to use flash effectively.  Many people state that they can always tell when flash is used as the images have a “flashed” look to them. By this they mean that the subject appears overly bright and unnaturally lit within the image. By applying varying levels of flash output, we are able control the degree of subject illumination independent of the ambient light. Keeping the flash and ambient exposure separate in your mind will help you better achieve your goal.

The image of the heron on the nest (above) is a good example of how I use flash to balance ambient light. Here are the steps I took to make this image using flash.

1. First, I used my in-camera spot meter to check the yellow background highlight and I set my exposure 1.3 stops above the mid tone (in this case, my exposure was 1/250 sec at f/8 at ISO 200).

2. Next, I focused my lens on the subject and read the distance scale on my lens (in this example, 10 ft). Since my flash was on the camera, the flash-to-subject distance was the same as the lens-to-subject distance (10 ft).

 

Where to check the focusing distance on your lens.

Where to check the focusing distance on your lens.

3. Then, I set my flash to manual mode, which allows me to control the flash output independent of the exposure. I used the Select button on the back of the flash, turning the dial to place the black bar even with the subject distance. (Note: Strobes will vary by manufacturer. Some use buttons, others wheels, or a combination of both to alter the flash output.) Altering the flash output moves the distance scale, and that is what you are concerned with at this point. Do not be concerned if the scale says 1:1 or 1/128. Just make sure the distance appearing on the scale (10 ft in this example) is the same as the focus distance on your lens (10 ft).

A few examples of where to find the focusing distance on your flash. Flashes set to manual.

A few examples of where to find the focusing distance on your flash. Flashes set to manual.

 

TIP: When you zoom to alter your lens focal length, the flash will also zoom to evenly illuminate the field of view. If you take a given quantity of light and squeeze it into a narrower or wider area, the output of the flash (known as the guide number) will vary. Thus, you will need to adjust the flash power each time you change the focal length of your lens. I suggest you manually fix the flash zoom to the widest focal length you plan on using. No worries if you are shooing a fixed lens.

If all other factors remain constant (f/stop. shutter speed, ISO and background illumination), both the background and the subject will be perfectly illuminated.

If you want to get a firm grasp on how to use flash effectively, consider taking Charles (Chas) Glatzer’s STL Tech Series Flash Seminar. Chas’ work has been celebrated internationally with over 40 prestigious awards for superior photographic competence demonstrated through photographic competition, advanced education, and service to the profession. His images are recognized internationally for their lighting, composition, and attention to detail and have appeared in many publications worldwide including National Geographic, Outdoor Photographer, Popular Photography, National Parks, Discover Diving, Smithsonian, Professional Photographer, Birder’s World, Birding, Nature Photographer, EOS, Digital PhotoPro, and many more.

Visit http://www.shootthelight.com/ to learn more.