Fill-flash in Nature Photography

There are many cameras on the market today with flash systems capable of producing balanced fill-flash photographs in ambient light. Using fill-flash can produce professional looking results. There are many uses for fill-flash in the field. Since outdoor light is often harsh and contrasty, fill-flash can keep shadows from going black, especially with transparency film. It can also bring out the brillance of foreground subjects such as flowers, animals, or even people that might otherwise blend in with the background under ambient lighting conditions.

Cameras with Automatic Fill-flash

If you are fortunate enough to have a camera system that provides automatic balanced fill-flash, then you only have to attach your flash to your unit and fire away. There are some accessories that are handy for nature photography such as off-camera flash synch cords and flash brackets that are designed for close-up nature work. If you plan to do a lot of close up work of flowers and insects, these are worthwhile investments.

Cameras Without Automatic Fill-flash

You can still use fill-flash if you don't have a camera with a built-in program for it. An older camera with TTL flash metering can be fooled into balancing flash with ambient light. If you have a dedicated unit, connect it to your camera, then, in the manual exposure mode, set your exposure for the ambient light. Then reset the ISO to a higher setting. The camera, thinking you have a faster film, will direct the flash to put out less light. The flash will be more closely balanced with the ambient light. A one stop increase in speed will reduce flash exposure by one stop. A two stop increase will reduce it by two stops. Resetting the ISO somewhere between one and two stops higher will give the best results for nature photography.

Let's take an example: You want to use fill-flash to fill in the shadows of some foreground flowers in an outdoor landscape. Your ambient light setting is 1/125 at f/16. You are shooting with ISO 100 film. Connect your flash and increase the ISO setting to 200, 320, or 400. The higher the setting, the more subtle the effect. 320 will probably be the best setting. And remember to reset the ISO to your original setting (100 in this example) before adjusting the ambient light exposure! Also make sure that your shutter speed is within the synch range for your camera. Older cameras usually synch up to 1/60 or 1/125 of a second; some as high as 1/250th of a second.

Really Old (But Great) Cameras With Automatic Flash

Another method I have read about, but haven't tried, may work with a camera without a dedicated flash or TTL, if you have an auto flash unit with two auto programs. Many inexpensive non-dedicated flash units have a flash sensor that automatically controls the amount of flash. To use these units, you set the ISO of your film on the flash unit, and then select one of the auto programs. Two are frequently offered, such as f/4 and f/8. Here's how you do it: Set your camera lens to f/8 (or the f/stop that matches the higher of your flash's auto programs) and set the shutter speed for the proper ambient light exposure. Make sure you are within your flash unit's synch range. Then select the f/4 program on your unit. Since the unit now thinks you are shooting at a larger aperture, it will put out less light. You should get about a two stop reduction for a subtly balanced image. Experiment with this, though, before you blow a lifetime shot.