Depth of field

Depth of field (DOF) is the range of distances that look acceptably sharp in a photograph or render. With a real camera it depends on the aperture, the focal length and how far away the subject is. A shallow depth of field keeps only the focused object crisp while the foreground and background melt into a soft blur; a deep depth of field keeps most of the scene sharp, from the nearest step to the horizon.

Depth of field in architectural visualization

Physical cameras in render engines follow the same logic: a lower f-number means a wider aperture and more blur. Focusing on a vase on a dining table and letting the living room behind it soften slightly steers the eye and gives an interior shot a photographic quality. Exterior and aerial images usually go the other way, with a deep depth of field, because the point is to show the whole building clearly.

Things to watch

Too much blur can make a scene look like a tabletop model, an effect that is especially strong in wide views seen from above. DOF can be calculated physically during the render or added in post-production using a Z-depth pass. The second route is fast and flexible, though it can struggle at the edges of glass, foliage and hair. For more on camera and lighting choices, see practical 3D render techniques.