Fewer than the number on the box suggests, because that number comes from a laboratory protocol with a named focal length and posture. Treat it as a comparison between two products rather than as a promise about your own hands.
A stop of stabilisation means one halving of the shutter speed that would otherwise be needed. Five stops claimed means five halvings, measured in conditions the maker describes — or does not.
What this catalogue publishes
Very little, and it is worth stating plainly. Across the 266 products surveyed here, no title names a measurement protocol at all; the German word for image stabiliser appears in two, and an optical stabilisation abbreviation in three. Where a stop count appears on a listing without the protocol beside it, this site records the number and says what is missing.
Why the protocol is the whole of it
Two makers quoting the same number against different protocols have not made the same claim. A figure with its protocol named can be compared with another figure measured the same way; a bare figure can only be compared with another bare figure, which is to say not compared at all.
What actually decides a sharp frame
Shutter speed first, and the light that allows it. Then the aperture — the long end of a variable zoom is where this bites hardest. Then support: a set of legs removes the question rather than reducing it, which is why the declared load and the section count of a tripod are worth more attention than an extra claimed stop.
Where this page and the maker’s own manual disagree, the manual decides. Every focal length, aperture, guide number, stop of stabilisation, load rating and sealing claim on this page is reported from the manufacturer’s own documentation, with its unit written as published, and named as such — none of it is measured here. An engraved figure is reported as the maker engraves it, and is never restated in another convention, because the two are not the same number. And for any figure quoted in stops: a stabilisation rating is a laboratory result obtained under a named protocol, not a promise about handheld work. Where a maker names the protocol and the focal length it was measured at, both are reported here beside the number. Where none is named, that absence is reported too, and no figure is inferred in its place.
What people ask before they commit
Why is the figure not reproducible at home?
Because it is measured against a protocol — a stated focal length, a defined posture, a rig that produces repeatable movement. Your stance, your breathing and the lens you actually own are none of those. The figure is honest about what it measured; it was never a claim about a particular photographer.
Does stabilisation help a moving subject?
No. It compensates for camera movement, not subject movement, so a walking child at a slow shutter speed stays blurred no matter how many stops are claimed. Subject movement is answered by shutter speed, which means by light, which means by aperture and sensitivity.
Last reviewed 12 September 2026