|Nikon D5, Sigma 35mm ƒ/1.4 DG Art, ISO 100, ƒ/1.4, 1/2500|
Where do you want the viewer to focus their attention - the hedge in the foreground, the man in the middle, or the trees in the distant background? Many professional photographers use the selective focus technique to control the viewer’s attention.
The apertures, called f-stops, are actually fractions. The f-stop ƒ/4, for example, is really ¼ (one fourth). What one fourth of, is a little beyond the scope of this article. Let’s just say that an f-stop is a fraction, ok? (ƒ/4 = 1/4th f8 = 1/8th). Typically these numbers are on the lens, 2.8, 4, 5.6, 8, 11, 16, 22 and so on.
Remember these are actually fractions: 1/2.8, 1/4, 1/5.6, 1/8, 1/11, 1/16 and 1/22. It provides a comparison of how much light each number lets through the lens. Therefore 1/5.6 allows more light through the lens than 1/22.
|Nikon D5, Sigma 35mm ƒ/1.4 DG Art, ISO 180, ƒ/8, 1/100|
Here’s the creative part: the smaller the opening (f-stop) in the lens, the less light is allowed in. Therefore, a greater area is in focus from the foreground to the background. If you want to throw most of the background out of focus, use ƒ/5.6 rather than
Today’s digital cameras allow the photographer to vary the aperture, preview the results, then make a decision about it’s effectiveness.
|Nikon D5, Nikon 85mm ƒ/1.8G, ISO 100, ƒ/1.8, 1/320|
A smaller aperture (ƒ/16 or ƒ/22) brings the foreground and background into sharper focus or a greater depth of field. It also allows for other compositional techniques to direct the viewer to the main subject of the photo.
|Nikon D5, Nikon 85mm ƒ/1.8G, ISO 100, ƒ/1.8, 1/4000|
|Nikon D5, Nikon 85mm ƒ/1.8G, ISO 100, ƒ/10, 1/320|