← ToolBox / 超焦距 H 计算

🧮 Hyperfocal Distance Calculator

Compute the hyperfocal distance from focal length, aperture and circle of confusion to maximise sharpness from near to infinity.

焦距 mm

光圈 f

弥散圆 mm

超焦距：H = f² ÷ (N·c) + f（mm，f 焦距、N 光圈值、c 弥散圆直径）；米口径 = H ÷ 1000（m）。校验：f、N、c 三项非空守卫。判据：无固定分级，光圈越小（N 越大）超焦距越近，对焦于超焦距可获得最大景深。

对焦到超焦距，景深从 H/2 延伸至无穷远。

📚 深度解析：超焦距计算

超焦距

50mm、f/8、全幅弥散圆 c=0.03mm：H = f²/(N·c)+f = 2500/(8×0.03)+50 ≈ 10433mm ≈ 10.4m；对 10.4m 聚焦，近界 5.2m 远界无穷。

收光圈扩清晰

同 50mm 收 f/16：H ≈ 50²/(16×0.03)+50 ≈ 5262mm ≈ 5.3m，近界约 2.6m 即全清，适合深景风光。

Item	Formula / Rule	Source / Standard
Hyperfocal formula	H = f² ÷ (N × c) + f, with f and c both in millimetres and H returned in millimetres	Kingslake, Optics in Photography, SPIE Press, 1992
Sharp range	Focusing at H keeps everything from H/2 to infinity acceptably sharp	Kingslake, Optics in Photography, SPIE Press, 1992
CoC basis	Full frame uses c = 0.03 mm, APS-C 0.02 mm and M4/3 0.015 mm	ISO 12231:2012 Photography — Vocabulary