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.
f4.0 @ 1/80sec, ISO 100, FL 80mm
email@example.com sec, ISO 100, FL 80mm
Using the smallest aperture for my Canon 24-105mm lens and using AV (aperture priority) setting with a focal length of 80mm, the depth of field is very narrow with only the title of the main book clearly visible. The shutter speed is the fastest of the three images published here at 1/80 sec. By increasing the size of the aperture to f16 the shutter speed slows to 1/6 sec and the depth of field is increased. In this image we can now see more of the title of the main book and can begin to pick out the titles of the books in the background. When the shutter is set to f22 (the smallest aperture) the shutter speed is significantly slower at 0.3 sec., however the depth of field is increasing with the authors name now visible but the titles of the books in the background remain blurred. The difference in depth of field between an aperture of f16 and f22 is not as significant as between f4.0 and f16.
Find a subject in front of a background with depth. Take a close viewpoint and zoom in; you’ll need to be aware of the minimum focusing distance of your lens. Focus on the subject and take a single shot. Then, without changing the focal length, set the focus to infinity and take a second shot.
Taken on a Canon 5D Mk III (full frame), 1/400 @ f4.0, FL 105mm. The first image is zoomed to 105mm with the model heron in focus in the foreground and without changing the viewpoint I moved the lens to infinity focus and the heron becomes blurred with the grass and frost in background now in focus.
Find a location with good light for a portrait shot. Place your subject some distance in front of a simple background and select a wide aperture together with a moderately long focal length such as 100mm on a 35mm full-frame camera (about 65mm on a cropped-frame camera). Take a viewpoint about one and a half metres from your subject, allowing you to compose a headshot comfortably within the frame. Focus on the eyes and take the shot.
I was probably a bit close to my husband for this exercise. However, it does demonstrate the way the shallow depth of field makes the subject stand out. Taken on a cropped sensor 4/3 Lumix GX7 set on Aperture Priority, 1/320 @ F 5.6, FL 42mm.
Given a very helpful comment on my blog regarding the portrait shot of my husband, I wonder if this would be a better option for the exercise. The background may still be a bit cluttered but the lighting is better. Taken with a Canon 5D Mk III using a 24-105mm lens and zoomed at 73 mm. 1/320 @ f4.0.