Depth is the illusion of recession into space behind the picture plane — the sense that some elements sit nearer and others further from the viewer.
Depth is constructed by a small set of pictorial cues: overlap, diminishing scale, atmospheric softening, linear perspective, and tonal gradation from foreground to background. A picture can have deep recessional space (a long view through a landscape), shallow space (a stage-like band a few inches deep), or no depth at all (everything pressed onto the plane). Description tends to ask not only how much depth a picture has but what kind — sharply ruled perspective reads differently from soft atmospheric falloff, and a stack of overlapping flat shapes reads differently again. Depth is one of the oldest pictorial concerns and the one modernism most insistently reduced or refused.
See also
- picture-plane — the surface depth opens behind
- flatness — depth’s refusal
- figure-ground — the most basic depth relation