Blur comes from two places: the camera moving and the subject moving. They need different solutions.
Camera shake: the reciprocal rule
The traditional rule says the slowest handheld shutter speed is about 1 ÷ (focal length × crop factor): 1/50 s with a 50 mm lens on full frame, 1/75 s on APS-C.
Two modern adjustments:
- Image stabilization adds stops: 4 stops turns 1/50 s into about 1/3 s in theory. Results vary by person and focal length.
- High-resolution sensors show smaller blur: for 40+ MP, double the speed.
The handheld shutter speed calculator applies both.
Holding technique
- Elbows in, camera against your face (viewfinder) rather than at arm's length.
- Exhale and press the shutter gently between breaths.
- Lean against a tree or rock, or rest the lens on your bag.
- Shoot short bursts — the second or third frame is often sharpest.
Subject motion
Stabilization doesn't freeze moving subjects. A bird, a running animal or waves need fast speeds regardless of focal length. The motion blur calculator uses the subject's speed and distance to find the speed for 1–3 pixels of blur. Rough guide:
- People walking: 1/250 s
- Birds perched: 1/500–1/1000 s
- Birds in flight: 1/2000–1/4000 s
- Waves crashing: 1/1000 s to freeze, 1/4 s to blur
When to stop handholding
In dim light, raising ISO is usually better than a blurry photo — modern noise reduction is excellent. When even high ISO isn't enough, it's tripod time.
About 1 min read · Updated 2026-10-20