Design & colour
Depth of field & hyperfocal
Explore thin-lens focus limits with a chosen blur criterion.
A clear answer. Here’s how.
Uses a paraxial thin lens and a stop at the lens. Let D=f²/(N×c), focus distance s and focal length f in the same units: near=sD/(D+s−f), far=sD/(D−s+f), and hyperfocal=D+f. Far limit is infinite at or beyond hyperfocal. Requires s>f. Blur criterion is supplied by you; diffraction, aberrations, pupil magnification and real-lens focus breathing are excluded.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Focal length (mm)
- 50
- Aperture f-number
- 8
- Focus distance from lens principal plane (m)
- 3
- Acceptable circle of confusion (mm)
- 0.03
Example result
- Near focus limit (m)
- 2.33790523691
- Far focus limit (m)
- 4.18526785714
- Total depth of field (m)
- 1.84736262024
- Hyperfocal distance (m)
- 10.4666666667
Paraxial thin lens with your supplied blur criterion. Distances are measured from the lens principal plane.