Use a combination of wide apertures, long focal lengths and close viewpoints to take a number of photographs with shallow depth of field. (Remember that smaller f numbers mean wider apertures.) Try to compose the out-of-focus parts of the picture together with the main subject. Add one or two unedited sequences, together with relevant shooting data and an indication of your selects, to your learning log.
Wide apertures create shallow depth of field, especially when combined with a long focal length and a close viewpoint. In human vision the eye registers out-of-focus areas as vague or indistinct – we can’t look directly at the blur. But in a photograph, areas of soft focus can form a large part of the image surface so they need to be handled with just as much care as the main subject.
Don’t forget that the camera’s viewfinder image is obtained at maximum aperture for maximum brightness and therefore at the shallowest depth of field. Use the depth of field preview button to see the actual depth of field at any particular aperture. (This is especially useful in film cameras where you don’t have the benefit of reviewing a shot immediately after you’ve taken it). It’s surprising to see the effect that a single f stop can have on the appearance of an image.
For this exercise I went to Wollaton Hall and Deer Park at dusk with my Canon 5D Mkiii and a Canon 70-300mm lens. This lens doesn’t have a particularly wide maximum aperture (5.6 at the longest focal length), but its maximum focal length of 300mm allowed me to take some shots of the deer from a respectful distance. Using the maximum aperture allowed for the deer to be in focus and the background to be blurred to get the desired depth of field.
Note: some of these images have been cropped and slightly adjusted for contrast and exposure using Lightroom.
Image 1: f/5.6 1/60s ISO 1600, focal length 300mm
This shot is heavily cropped to show the deer’s breath condensing in the cold air. The background is blurred with the light from the sun setting behind the trees creating a pink bokeh effect.
Image 2: f/5.6 1/125s ISO 1600, focal length 300mm
Here the grass at the front of the image and the background are out of focus.
Image 3: f/5.6 1/125s ISO 1600, focal length 170mm
Here the trees and deer in the background are blurred. This accentuates the main subject matter in the shot.
Image 4: f/5.6 1/60s ISO 1600, focal length 300mm
Here the grass in the foreground, and the trees and grass in the background, are blurred.
Image 4: f/5.0 1/60s ISO 1600, focal length 210mm
Here the grass blurs as it extends into the distance. The trees and shape of the deer in the background are a hazy blur.
Image 5: f/5.0 1/80s ISO 1600, focal length 200mm
Here the grass blurs as it extends into the distance. The trees in the background are a hazy blur as the doe daintily steps into the frame.