Bald Eagle and depth of field

Perched Bald Eagle at f/6.3Perched Bald Eagle at f/6.3D200, f6.3, 1/800, ISO 400, +0.7 EV, 200-400mm VR with 1.4x TC at 400mm, natural light, not baited

I found this Bald Eagle (Haliaeetus leucocephalus) perched on an old post going into Bear River National Migratory Bird Refuge in northern Utah. The eagle was “sticky”, a term my friends and I use when the weather is cold enough to make the birds less likely to fly upon approach. Because I had time to photograph this eagle I tried using several different depths of field which can make and impact on the fore and backgrounds of an image.

For the image above I selected an f-stop (aperture) of 6.3, the eagle and the perch are sharp and in focus while the distant mountains, water and vegetation are out of focus and have a soft appearance. The foreground vegetation is softened and out of focus as well.

Perched Bald Eagle at f/22Perched Bald Eagle at f/22 – D200, f22, 1/80, ISO 400, +0.7 EV, 200-400mm VR with 1.4x TC at 400mm, natural light, not baited

For the photo above I selected an f-stop of 22, the eagle and the post are as sharp and in focus as the first photo, but there are differences in the fore and background of these two images taken just 5 frames apart.

The foreground vegetation has more definition and the shapes of the stems are more clearly identifiable. The water has more texture to the surface than the image taken at f6.3 and the vegetation in the background between the water and the mountains show more detail. There are also visible details in the the distant mountains that show the shapes of trees and the brush on the slopes.

I believe these two eagle pictures illustrate what changes the depth of field settings can have on the appearance of an image. Some photographers “blur” the background of their images in post processing, I prefer to use the bokeh of my lens and aperture settings at the time of creation to create a more natural effect without manipulation.



  1. Scott April 16, 2012 at 8:29 am

    I like to find a ‘sticky’ bird. I’ll be adding that term to my birding vocabulary 🙂

    • Mia McPherson April 18, 2012 at 8:13 am

      I love sticky birds Scott, it means I can take more photographs of them and usually I can get just a little closer too.

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