Circle of Confusion
Get the circle of confusion diameter used in depth-of-field math for a sensor.
About Circle of Confusion
The accepted circle of confusion is a small fraction of the sensor diagonal, with stricter values for large prints viewed closely. Depth-of-field results only mean something when the blur tolerance (CoC) is set, so this value feeds every DoF estimate.
Formula
Circle of Confusion
CoC = sensor diagonal / 1500 (standard) or / 1730 (print)
- CoC
- Circle of confusion as a fraction of the sensor diagonal
Worked example
With the default values below, Circle of Confusion returns CoC (standard) of 0.029. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Sensorone of Full frame (43.3mm diag), APS-C (28.4mm diag), Micro 4/3 (21.6mm diag), 1-inch (15.9mm diag), Phone (8mm diag)
- Full frame (43.3mm diag)
Results
- CoC (standard)
- 0.029 mm
- CoC (strict print)
- 0.025 mm
- Sensor Diagonal
- 43.27 mm
Step by step
- 1Values used
- 2Circle of Confusion
- 3CoC (standard)= 0.029 mm
- 4CoC (strict print)= 0.025 mm
- 5Sensor Diagonal= 43.27 mm
Assumptions and limits
- The result is derived only from the single input listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Circle of Confusion calculated?
CoC = sensor diagonal / 1500 (standard) or / 1730 (print) The accepted circle of confusion is a small fraction of the sensor diagonal, with stricter values for large prints viewed closely.
Why does Circle of Confusion matter?
Depth-of-field results only mean something when the blur tolerance (CoC) is set, so this value feeds every DoF estimate.
What values do I need to enter?
This calculator takes 1 input: Sensor. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.