In previous articles, we briefly introduced the formula for calculating depth of field. Here is a simple recap:

The formula for depth of field is shown below, where:

δ: diameter of the permissible circle of confusion

F: aperture value of the lens

f: focal length of the lens

L: focusing distance

ΔL₁: front depth of field

ΔL₂: rear depth of field

ΔL: total depth of field

Front depth of field:ΔL₁ = FδL² / (f² + FδL)

Rear depth of field:ΔL₂ = FδL² / (f² − FδL)

Total depth of field:ΔL = ΔL₁ + ΔL₂ = (2f²FδL²) / (f⁴ − F²δ²L²)

It can be seen from formulas (1) and (2) that the rear depth of field is greater than the front depth of field.

As shown in the depth of field calculation formula, depth of field depends on the lens aperture, focal length, shooting distance, and the requirements for image quality (reflected in the size of the permissible circle of confusion).