Camera Field Of View Calculator
Calculate horizontal, vertical, and diagonal camera field of view (FOV) in degrees and scene dimensions from sensor size, focal length, and distance.
Open toolCircle Of Confusion Calculator
Enter your camera sensor width and height, print diagonal, viewing distance, and visual acuity in the Circle Of Confusion Calculator below to compute custom Sensor CoC in millimeters and microns alongside Zeiss (d/1730) and standard (d/1500) benchmarks.
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Enter the inputs, then select Calculate Circle of Confusion.
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How Circle Of Confusion Calculator works
The Circle Of Confusion Calculator computes your sensor diagonal, determines the print enlargement factor (Print Diagonal / Sensor Diagonal), calculates the maximum imperceptible blur circle on the print based on viewing distance and visual acuity, and divides by enlargement to find the exact CoC on the sensor plane.
Sensor CoC (mm) = ((ViewingDist / 250) / Acuity_lp_mm) * (SensorDiagonal / PrintDiagonal).
Outputs Sensor CoC in both millimeters (e.g., 0.029 mm) and micrometers/microns (e.g., 28.8 um) plus diffraction-limited aperture (f-stop where Airy disk diameter equals CoC).
Circle Of Confusion Calculator Quick Reference & Input Guide
Review the input parameters, allowed value ranges, and worked reference cases for the Circle Of Confusion Calculator below before running your calculation.
| Parameter / Scenario | Default / Sample Value | Rule or Allowed Range | Output / Usage Note |
|---|---|---|---|
| Input: Sensor width | 36 | Range: 1 to 300 | Required workspace parameter |
| Input: Sensor height | 24 | Range: 1 to 300 | Required workspace parameter |
| Input: Final display or print diagonal | 300 | Range: 10 to 5000 | Required workspace parameter |
| Input: Viewing distance | 250 | Range: 50 to 20000 | Required workspace parameter |
| Worked Case 1: Full Frame 36x24 mm sensor (300 mm print at 250 mm distance, 5 lp/mm) | Preloaded / test values | Sensor Diagonal (d) = sqrt(W^2 + H^2); Enlargement (E) = PrintDiagonal / d; Print CoC = (ViewingDistance / 250) / Acuity; Sensor CoC = Print CoC / E | Sensor diagonal is 43.27 mm and enlargement is 6.93x. Print CoC is 0.200 mm, yielding a custom Sensor CoC of 0.0288 mm (28.8 um), matching d/1500 (0.0288 mm) and slightly looser than Zeiss d/1730 (0.0250 mm). |
| Worked Case 2: APS-C 23.5x15.6 mm sensor with critical 7 lp/mm acuity | Preloaded / test values | Sensor Diagonal (d) = sqrt(W^2 + H^2); Enlargement (E) = PrintDiagonal / d; Print CoC = (ViewingDistance / 250) / Acuity; Sensor CoC = Print CoC / E | Sensor diagonal is 28.21 mm. At 300 mm print diagonal, 250 mm viewing distance, and 7 lp/mm acuity, custom Sensor CoC tightens to 0.0134 mm (13.4 um) vs. Zeiss d/1730 of 0.0163 mm. |
How to use Circle Of Confusion Calculator step by step
Find your exact CoC value before calculating hyperfocal distance or depth of field.
Enter sensor width and height in mm
Input your active sensor width and height (36 x 24 mm for Full Frame, 23.5 x 15.6 mm for APS-C).
Set print diagonal and viewing distance
Enter the final print or display diagonal in mm (300 mm for an 8x10 print) and observer viewing distance (250 mm standard near point).
Set visual acuity and compare against Zeiss d/1730
Keep 5 lp/mm for standard viewing or raise to 7-8 lp/mm for critical exhibition prints, then click Calculate Circle of Confusion.
Worked examples for Circle Of Confusion Calculator
Compare standard 8x10 viewing on Full Frame against critical gallery viewing on APS-C.
Full Frame 36x24 mm sensor (300 mm print at 250 mm distance, 5 lp/mm)
Sensor diagonal is 43.27 mm and enlargement is 6.93x. Print CoC is 0.200 mm, yielding a custom Sensor CoC of 0.0288 mm (28.8 um), matching d/1500 (0.0288 mm) and slightly looser than Zeiss d/1730 (0.0250 mm).
APS-C 23.5x15.6 mm sensor with critical 7 lp/mm acuity
Sensor diagonal is 28.21 mm. At 300 mm print diagonal, 250 mm viewing distance, and 7 lp/mm acuity, custom Sensor CoC tightens to 0.0134 mm (13.4 um) vs. Zeiss d/1730 of 0.0163 mm.
Feed your custom CoC directly into Depth of Field calculations
Copy the calculated Sensor CoC (in mm) and paste it into the Depth Of Field Calculator for hyperfocal and near/far focus limits tailored to your print size.
How to interpret the Circle Of Confusion Calculator output
Compare your Custom Sensor CoC against Zeiss d/1730 and check the diffraction limit.
The headline result displays your Custom Sensor CoC in millimeters and microns. Breakdown cards show Sensor diagonal & enlargement ratio, Print-plane CoC, Zeiss d/1730 and d/1500 reference values, and the Diffraction-limited f-stop (where green-light Airy disk = CoC).
Input limits, assumptions, and related tools
Remember that CoC is a perceptual viewing threshold, not a physical property of the lens alone.
Normal 20/20 human vision resolves about 1 arcminute (~5 line pairs per mm at 250 mm viewing distance). To compute near and far focus distances using your CoC, open the Depth Of Field Calculator.
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Open toolCircle Of Confusion Calculator: common questions
Answers about using Circle Of Confusion Calculator and understanding its results.
What is the Circle of Confusion (CoC) in photography?
The Circle of Confusion is the largest blur spot on an image sensor that a human observer still perceives as a sharp point on the final print or display at a given viewing distance and enlargement ratio.
Where do the d/1500 and Zeiss d/1730 rules come from?
On a 35mm full-frame sensor (diagonal d = 43.27 mm), enlarging to an 8x10 inch print (diagonal ~300 mm) viewed at 250 mm (10 in) with 5 lp/mm visual acuity gives CoC = 43.27 / 1500 = 0.0288 mm (often rounded to 0.030 mm). The stricter Zeiss formula uses d / 1730 = 0.025 mm.
What happens to the Circle of Confusion if you stand twice as far from a twice-as-large print?
If print diagonal and viewing distance scale up by the same factor (for example, viewing each print from a distance equal to its diagonal), the enlargement ratio and viewing-distance ratio cancel out, leaving Sensor CoC unchanged!
How do high-resolution pixel-peeping or cropping affect CoC?
Cropping an image (or viewing a 45 MP image at 100% zoom on a monitor from 500 mm away) increases the effective enlargement E without increasing viewing distance, which requires a smaller Sensor CoC (often 0.010 to 0.015 mm) and yields a shallower perceived depth of field.
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