SHALOW DoF

a subject from a distracting foreground and background. Portrait photographers routinely use lenses that have wide maximum apertures, such as f/1.2, to create a wafer-thin depth of field and bucket loads of background blur that keeps the viewer’s attention where it should be – on the person.

When you want to increase the depth of field and get more of a scene or subject to look sharp. Typically, you’d use a narrow aperture when you’re photographing a landscape or shooting a close-up. Narrow apertures lead to long exposure