I visited some hummingbirds in Phoenix, Arizona this morning. They are surely fast fliers and without a flash it would be impossible to even see their wings while they are hovering. I put a folding bounce diffuser onto my Vivitar flash on camera, and used the sky as a background. I seem to have got the flash exposure (aperture) and ambient light exposure (aperture and shutter speed, F-11@1/100 sec.) just right on this sunny morning at 8:45 am.