Sometimes, my use of flash is fairly conventional. For example, with this image below of a buff-tailed coronet, I used flash to balance the light between the sunlit leaves in the background and my main subject, which was in shadow. The flash also reveals the bird's brilliant colors. As is often the case when using fill flash, I reduced the flash from full power, setting my flash compensation at -1. This helps keep the flash illumination from looking artificial, as at reduced power it mixes somewhat with the ambient light for a more natural result. Andes Mountains, Ecuador. Canon 5DIII, 560mm, ISO 400, f/8, 1/15 second.
Similarly, this cheetah was in a field lit by gorgeous morning backlight, but the cheetah was sitting in the shade. I used flash at low power to add some fill light to the cheetah, and to add catchlights to the subject's eyes. Nxai Pan National Park, Botswana. Canon 70D, 513mm, ISO 400, f/5.6, 1/200 second.
Likewise, with this proud male lion resting to escape the heat of the day, the lion was partially in the shade, with deep shadows falling across the lion's face. I used flash at low power to add some fill light to the shadows, balancing the exposure. Notice that I didn't eliminate the shadows entirely; I wanted to keep enough of the shadows to add some interest to the shot. Central Kalahari Game Reserve, Botswana. Canon 5DIII, 473mm, ISO 100, f/5.6, 1/160 second.
I also like to use flash in a more creative fashion. For this image below of a great blue heron, I positioned the camera so that the colorful twilight sky was reflected in the waters around the bird. Waiting for a moment when the heron stood perfectly still, I triggered an exposure to capture the faint ambient light, firing my flash to illuminate the heron. Although the water appears smooth, it was in fact rippled by a slight breeze. The long exposure blurred the rippled water, but you can actually see the reflection of the ripples frozen in time by the flash on the heron itself. Blackwater National Wildlife Refuge, USA. Canon 20D, 500mm, ISO 400, f/5.6, 1/4 second.
I also like using flash to mix long exposure blur with stopped-action. In this image of willets roaming the beach at night, I used flash to freeze their frenetic motion, allowing the long exposure to capture the reflection of the rising full moon in the water. The result is a "ghostly" look, as if two separate exposures had been combined. Huntington Beach State Park, USA. Canon 1DsII, 300mm, ISO 400, f/11, 3.2 seconds.
Pro photographer Glenn Bartley recently released a great ebook on the use of flash called Flash Simplified: A Guide for Nature Photographers. This ebook provides a solid foundation of how and when to use flash as a tool to create better nature photographs, and an understanding of the basic flash controls and the most common scenarios for when to use each. This ebook provides practical tips for using flash in the field, and also explores more unconventional ways to use off-camera flash and multiple flashes. If you want to learn more about the creative use of flash for nature photography, Glenn's ebook Flash Simplified: A Guide for Nature Photographers is available for purchase on my online store.