I have written about this in the past but my exposure settings for birds are always fully manual except in some very specific circumstances. A recent sequence illustrated the reason for this quite nicely despite not resulting in any special images.

On a walk around the base track of Mount Maunganui my camera always comes along. There is always something to see and episodically some gems like a Reef heron or Wandering tattler will make an appearance. On this walk it was the usual Pied shags, gulls and passing gannets. The light was harsh sun, so not lovely.

A gull perched on a rock gave me the chance to look at some rim lit options keeping the exposure correct to protect the highlights. Birds, being birds, are prone to take flight and this gull was no exception, flying down off its perch in front of the shaded rock and then over the sea reflecting the sun. This gallery shows uncropped, unprocessed images from the sequence.

With the exposure set manually – shutter speed, aperture and ISO (Manual with auto ISO is an auto mode) – the exposure remains constant despite the background going from almost black to bright specular highlights. Any auto mode would have adjusted for the changing luminance of the scene, overexposing the bird in the earlier frames and underexposing in the brighter frames.

The only drawback to this approach is if the bird were to fly from bright light into shade. This is not often a situation I have run into but even then the ISOless nature of Nikon sensors allows shadow recovery with little, if any, penalty.

The reverse situation of a bird flying from shade into bright light is more of a challenge as an exposure set for the shade will seriously overexpose the bird when it flies into the sun resulting in unrecoverable blown highlights. In that situation I choose my exposure for the situation that will give the best background and not shoot in the other lighting scenario.