D4 and Hummingbirds

Terry,

Great Question. The reason for f/18 and f/20 is for Depth of Field. The birds are quite small, and therefore I'm only 15-20 feet away with a 500mm. I need to generate enough depth to get the whole wing, tail and flower in focus. Most of the time there is only about 4-6" of DOF.

I'd rather be shooting at f/16 and below to be in a sweeter spot of the lens, but then I would be struggling with out of focus objects.

I hope that helps.
Matt Shetzer

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Matt Shetzer
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D4, 16-35mm, 24-70mm, 70-200mm, 105mm macro, 200-400mm, 500mm