Depth of Field Calculator
Find the near limit, far limit and total depth of field from focal length, aperture and focus distance.
Total depth of field1.87m
Near limit2.33m
Far limit4.21m
First the hyperfocal distance H = f² ÷ (N · c) + f (in mm, then converted to metres). The near limit ≈ H · s ÷ (H + s) and the far limit ≈ H · s ÷ (H − s), where s is the focus distance. Total depth of field is far − near. For a 50 mm lens at f/8 focused at 3 m with a 0.03 mm circle of confusion: H ≈ 10.47 m, so the sharp zone runs from ≈ 2.33 m to ≈ 4.21 m — about 1.87 m deep. When the focus distance reaches or passes the hyperfocal distance the far limit becomes infinite (everything beyond stays sharp).
Questions
How is depth of field calculated?
It starts from the hyperfocal distance H = focal² ÷ (aperture × circle of confusion) + focal. The near limit is about H × distance ÷ (H + distance) and the far limit about H × distance ÷ (H − distance); the total depth of field is the gap between them.
What circle of confusion should I use?
0.03 mm is a common value for a full-frame (35 mm) sensor. Smaller sensors use a smaller circle of confusion — roughly 0.02 mm for APS-C and 0.015 mm for Micro Four Thirds.
Why does the far limit sometimes go huge?
When the focus distance reaches the hyperfocal distance, the far limit extends to infinity — everything from the near limit outward is acceptably sharp. Near that point the far-limit figure grows very large.