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Camera Depth of Field
Estimate near and far acceptable focus limits for a chosen focus distance, lens and circle of confusion.
Focal length (mm): 1–1000; Aperture (f-number): 0.7–64; Focus distance (m): 0.01–100000; Circle of confusion (mm): 0.001–0.1
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Camera Depth of Field
Focal length (mm): 50 Aperture (f-number): 4 Focus distance (m): 5 Circle of confusion (mm): 0.03
- Near limit (m)
- 4.040078
- Far limit (m)
- 6.558237
Use millimetres internally: f = focal length, N = f-number, s = focus distance × 1000, c = chosen sensor-plane circle of confusion. Require s > f. Let q = N c (s − f), H = f²/(N c) + f. Near = s f²/(f² + q); far = s f²/(f² − q), or infinity when s ≥ H. Convert limits to metres. This paraxial thin-lens model measures subject distances from the front principal plane, not the sensor mark or front glass, and assumes pupil magnification of one. Acceptable sharpness depends on the chosen c and viewing conditions; no universal sharp boundary is implied. Diffraction, aberrations, focus breathing, motion and lens-specific behaviour are excluded. Check the actual camera image.
Methodology
How it works
Use millimetres internally: f = focal length, N = f-number, s = focus distance × 1000, c = chosen sensor-plane circle of confusion. Require s > f. Let q = N c (s − f), H = f²/(N c) + f. Near = s f²/(f² + q); far = s f²/(f² − q), or infinity when s ≥ H. Convert limits to metres. This paraxial thin-lens model measures subject distances from the front principal plane, not the sensor mark or front glass, and assumes pupil magnification of one. Acceptable sharpness depends on the chosen c and viewing conditions; no universal sharp boundary is implied. Diffraction, aberrations, focus breathing, motion and lens-specific behaviour are excluded. Check the actual camera image.
Method and assumptions documented by Techrider.live
2026-11-07
Frequently asked questions
Why can the far limit be infinity?
At or beyond the hyperfocal focus distance, distant objects remain within the chosen circle-of-confusion criterion. This does not mean everything is perfectly sharp; the near limit and the viewing criterion still apply.