The Screaming Eagle & when not to use flash

Bald Eagle (Haliaeetus leucocephalus Pygarge à tête blanche) Homer Alaska, USA. ©Christopher Dodds http://www.chrisdoddsphoto.com All Rights Reserved. Canon EOS 1Ds Mark III, 500mm F4 IS, 2X II Tele-converter,1.4X II Tele-converter, Gitzo tripod and Wimberley Head II. ISO 640, F20 1/80s Manual Exposure and Manual Focus. Full Frame. Click HERE to order a print or license image for publication.

I have been to Alaska to photograph Bald Eagles many times, and always wish for golden light during the first, and last, hour of light. It's often cloudy when I'm there, and my flash is always mounted and ready to go. Typically I would use some light fill flash on heavily overcast days; even when this bird looked to the side I used fill flash. The thing is, I was looking for a perfectly framed, tight portrait of a screaming eagle; and I wanted to see straight down it's throat without any shadows. The single best time to get this shot was during a snowstorm when the clouds and snow diffuse the natural light and bounce it around creating a virtually shadowless world.  It was hovering around freezing and the snow was changing to rain (as we'd endured for a couple of days). I saw this eagle singing and decided to dedicate some time to this shot. So, why no flash? Simple, It would have created a shadow from the front part of it's beak that is hooked downward.

Comments welcome & appreciated.