How is the number of stops of benefit from vibration reduction measured?

Asked 10/2/2014

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People often say vibration reduction/image stabilization gives you “extra stops” of hand-holdability, meaning you can use a slower shutter speed and still get a sharp image. How is that stop benefit actually determined? For example, how would you work out whether VR gives you 1, 2, or more stops of advantage?

stops vibration-reduction handheld image-stabilization shutter-speed

Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0

Photography Stack Exchange contributor

11y ago

2 Answers

I don't know anyone who calculate those kind of thing, people just pull numbers out of their .. hemm .. I mean people produce approximate numbers based on their rich experience.

If you did want to calculate this the method would be:

Test what is the slowest shutter speed that give you sharp hand-held images with IS turned off
Test what is the slowest shutter speed that give you sharp hand-held images with IS turned on.
Calculate the difference in stops.

Obviously the "slowest shutter speed that give you sharp hand-held images" depends on a lot of external factors (from camera holding technique to how tired you are at the moment) so that is why the numbers are mostly made up, sorry, I meant to say approximation based on experience.

Originally by user2481. Source · Licensed CC BY-SA 4.0

user2481

11y ago

AI Answer

Generated from our catalog & community — verify before relying on it.

The “stop” benefit of VR/IS is measured by comparing the slowest shutter speed you can hand-hold sharply with stabilization off versus on.

A stop is a doubling or halving of exposure time. So if stabilization lets you use a shutter speed 2× slower, that’s 1 stop; 4× slower is 2 stops; 8× slower is 3 stops.

Example:

Without VR, your sharp limit is 1/60 s
With VR, your sharp limit is 1/15 s

1/15 is 4 times longer than 1/60, so that is a 2-stop advantage.

In practice, you determine this by testing:

Take a series of handheld shots with VR off and find the slowest speed that still gives sharp results.
Repeat with VR on.
Convert the difference in shutter speed into stops.

Keep in mind these numbers are approximate, because results depend on your technique, focal length, fatigue, and how consistently sharp you need the images to be. That’s why people often quote stabilization performance as a real-world estimate rather than an exact figure.

How is the number of stops of benefit from vibration reduction measured?

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