Macro DOF Calculator — Depth of Field at Magnification

DOF decreases with the square of magnification. At 1:1 (1x), DOF is measured in millimetres. At 2:1 (2x), it is even shallower. At 1:1 and f/8 on full frame, total DOF is only about 0.93mm. This is why focus stacking is essential for macro photography.

At magnification M, the effective aperture is N x (1+M). At 1:1 magnification and f/8, the effective aperture is f/16. This means 2 stops of light loss and diffraction equivalent to f/16. TTL metering compensates automatically.

Use f/5.6 to f/11 set on the lens. At 1:1, this gives effective apertures of f/11 to f/22. Beyond f/11 set, diffraction noticeably softens the image. For maximum sharpness, use f/5.6-8 and focus stack for more depth.

Yes. The standard DOF formula assumes focus distance is much greater than focal length. At macro distances, the simplified formula DOF = 2cN(1+M)/M² is more accurate. It shows that DOF depends only on magnification, aperture and CoC — not focal length.