Depth of Field Calculator
Enter focal length, f-number, subject distance, and circle of confusion. This optical estimate uses a symmetric thin-lens model and does not promise a photographic result.
A QUICK WALKTHROUGH
How to use this tool
- Enter the lens focal length and f-number.
- Enter focus distance and the chosen circle of confusion.
- Calculate the hyperfocal, near, and far limits.
Model and parameters
H = f²/(N·c) + f. Near = Hs/(H+s−f). Far = Hs/(H−s+f), or infinity when s ≥ H+f. Here f and c are millimetres, N is the f-number, and s is focus distance converted to millimetres.
Interpretation limit
Circle of confusion is a chosen acceptability criterion. The model omits lens design, pupil magnification, focus breathing, diffraction, sensor processing, viewing size, and individual acuity; it cannot guarantee what appears sharp in a photograph.
GOOD TO KNOW
Common questions
Which circle of confusion should I use?
Use the criterion required by your own format and output assumptions. The calculator does not infer one from a camera model.
Why can the far limit be infinity?
In this model, focusing at or beyond the hyperfocal threshold makes the far denominator zero or negative.