Photography Calculators

Optics & depth of field

Macro Depth of Field Calculator

At 1:1, DoF is a millimetre-scale slab even at f/8. This is the standard close-up formula with an optional pupil factor for lenses that are not symmetrical. If the total is thinner than the subject, you stack — you do not just stop down until diffraction wrecks the file.

Inputs

Units
f/

Effective taking aperture if you know it; otherwise the setting on the lens.

×

1 means 1:1. A 2:1 optic is 2. Cropping in post is extra magnification.

mm

Same CoC convention you use for ordinary DoF.

Exit/entrance pupil ratio. Leave at 1 for symmetrical macros unless you have the lens’s p.

Results

Total depth of field
0.960mm
Total depth of field
0.0010m

Recommended gear

Calculation method

Total geometric DoF in millimetres is twice the f-number times CoC times (1 + magnification/pupil factor), all divided by magnification squared. At 1:1 with P = 1 that is 4·N·c. Convert to metres by dividing by 1000. Pupil factor P ≠ 1 on some retrofocus or tele-macros; leave it at 1 if you do not have the figure.

Exact formula

DoF_mm = 2·N·c·(1 + m/P) / m². totalDoFM = DoF_mm/1000. Limits: Geometric close-up DoF (Lefkowitz); diffraction, stacking overlap, focus breathing and bellows factor on the exposure are omitted; pupil factor P = exit/entrance, not a crop factor.

Effective f-number

At 1:1 a lens set to f/8 is closer to f/16 for exposure. This calculator uses the aperture you type for DoF geometry; it does not apply bellows factor to shutter speed. Meter or chimp the histogram.

Stack step size

A practical step is about one-third of total DoF so frames overlap. If total DoF is 0.6 mm, step ~0.2 mm on the rail.

Frequently asked questions

Why is 1:1 so thin?

DoF falls with the square of magnification. Double the magnification and you have about a quarter of the DoF, aperture unchanged. That is why 2:1 almost always means a stack.

Should I stop down to f/22?

You gain geometric DoF and lose microcontrast to diffraction. On a modern sensor, f/8–f/11 plus a short stack usually beats one f/22 frame. Shoot a test pair.

What is pupil factor?

p is exit pupil over entrance pupil. Many dedicated macros sit near 1. If the front glass looks much larger than the rear, p is not 1 and the DoF formula shifts.

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