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Handheld Shutter Speed Calculator (Reciprocal Rule)

Find the slowest shutter speed you can hand-hold without camera shake using the reciprocal rule, adjusted for crop factor, image stabilization stops and high-resolution sensors.

Focal length

Sensor

Image stabilization

Sharpness standard

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How it works

equivalent focal length = focal length × crop factor · slowest shutter = 1 ÷ (equivalent focal length × sharpness factor) · with stabilization: × 2^stops

The reciprocal rule says you can hand-hold a lens at a shutter time of about one over its focal length — 1/50 s for a 50 mm lens on full frame. Because a crop sensor is enlarged more for the same print, use the full-frame equivalent focal length. Modern 30–60 megapixel sensors reveal shake that older cameras hid, so many photographers double the speed. Optical or in-body stabilization lets you slow down by its rated number of stops, but it cannot freeze a moving subject — see the motion blur calculator for that.

Worked example

A 50 mm lens on an APS-C camera (1.5× crop) acts like 75 mm, so the slowest safe handheld speed is 1/75 s — use 1/80 s. With 4 stops of stabilization you could go to about 1/4.7 s — set 1/5 s.

Sources: Wikipedia — Image stabilization · Wikipedia — Crop factor

Frequently asked questions

What is the reciprocal rule?

A rule of thumb that the slowest shutter speed for sharp handheld shots is 1 divided by the (full-frame equivalent) focal length: 1/200 s at 200 mm, 1/24 s at 24 mm.

Does crop factor matter for camera shake?

Yes. A crop sensor enlarges the image more, so shake is magnified too. Multiply the focal length by the crop factor before applying the rule.

How many stops does image stabilization give?

Lens and body systems are rated at 3–8 stops by CIPA tests. In practice expect a bit less, especially at long focal lengths; each stop doubles the usable shutter time.

Why are my shots blurry above the reciprocal speed?

Either the subject moved (stabilization does not help with that), the camera has a very high resolution, or your technique needs help — brace your elbows, exhale and squeeze the shutter, or use burst mode.

Related calculators

Motion Blur Shutter Speed Calculator

Find the slowest shutter speed that freezes a moving subject from its speed, distance, focal length, sensor size and resolution, or see how many pixels of motion blur a shutter speed gives.

Crop Factor Equivalent Focal Length Calculator

See what focal length your lens really behaves like on a crop sensor — plus the equivalent aperture for depth of field.

Equivalent Exposure Calculator

Keep the same exposure when you change aperture, shutter speed or ISO: enter your metered settings, change two of them and get the third, with the nearest standard setting and the stops each change adds.

Depth of Field Calculator

Find the near limit, far limit and total depth of field for any lens, aperture and focus distance — plus the hyperfocal distance for your sensor.

ND Filter Shutter Speed Calculator

Screw on a neutral-density filter and get the new shutter speed instantly — with the stops, ND number and optical density it costs you.

This calculator is for educational purposes. Double-check important results before acting on them.