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超焦距与景深计算器

根据任意焦距、光圈、传感器尺寸和对焦距离，计算超焦距及可接受清晰度的近/远极限，非常适合风光摄影。

焦距（mm）

光圈（f/）

传感器（弥散圆 CoC）

对焦距离

单位

超焦距

—

在此处对焦，清晰范围为 — 到 ∞

对焦处的景深

—

近端 — · 远端 —

光圈	超焦距	近端极限	远端极限	总景深

计算原理

超焦距 H = f² / (N × c) + f，其中 f = 焦距，N = 光圈值，c = 弥散圆直径。近端极限 = (H × s) / (H + (s − f))。远端极限 = (H × s) / (H − (s − f))；结果为负表示无穷远。

在超焦距处对焦可获得最大景深：从 H/2 到无穷远的范围都能保持可接受的清晰度。

计算原理

Hyperfocal distance is computed as H = f squared / (N x c) + f, where f is focal length, N the f-number and c the circle of confusion for your sensor. Near and far limits come from the standard depth-of-field pair: near = (H x s) / (H + (s - f)) and far = (H x s) / (H - (s - f)), with s your focus distance. When that far denominator falls to zero or below, the tool prints infinity.

The Sensor (CoC) dropdown is the setting most people overlook, and it feeds c directly: 0.030 mm for full frame, 0.020 mm for APS-C Nikon / Sony, 0.019 mm for APS-C Canon, 0.015 mm for Micro Four Thirds, 0.011 mm for 1-inch, plus 0.038 and 0.044 mm for medium format. Focal length, aperture and focus distance default to 24 mm, f/8 and 3 m, switchable to feet.

Circle of confusion is a convention rather than a measurement. These values work out to roughly the sensor diagonal divided by 1,440, which assumes a modest enlargement viewed at a normal distance. Pixel-peep at 100% and your usable depth of field will be noticeably shallower than the table suggests. The comparison rows also run f/2.8 through f/22 whether or not your lens offers them, and diffraction is not modelled, so the gain at f/22 is overstated.

常见问题

Where should I focus for a sharp landscape?

Focus at the hyperfocal distance shown and everything from half that distance to infinity falls within the acceptable-sharpness limits. At the default 24 mm, f/8, full frame, that means focusing about 2.42 m away for sharpness from roughly 1.21 m onward.

Why does the far limit show the infinity symbol?

Once your focus distance reaches or exceeds the hyperfocal distance, the far limit is unbounded. The tool detects that H - (s - f) has dropped to zero or below and prints the infinity symbol rather than an implausibly large number.

What circle of confusion should I use for APS-C?

The presets are 0.020 mm for Nikon and Sony APS-C and 0.019 mm for Canon APS-C, reflecting their slightly different sensor sizes. Smaller sensors take a smaller circle of confusion because the captured image must be enlarged more to reach the same print size.

Does stopping down to f/22 really give more sharpness?

The table shows depth of field still growing at f/22, but it does not model diffraction, which softens the entire frame at small apertures. On most modern lenses f/8 to f/11 is the practical limit before diffraction cancels out the extra depth.

Is hyperfocal focusing the same as focusing on infinity?

No. Focusing at infinity throws away the near half of your available depth of field. Focus at the hyperfocal distance instead and you keep infinity acceptably sharp while gaining everything from half the hyperfocal distance forward, which the tool shows for you.

别名

hyperfocal distance calculatordepth of field calculatorlandscape sharpness calculator

超焦距与景深计算器

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