Because something moved, and on a tripod it is usually the camera rather than the scene: the shutter firing, a hand on the body, wind, or a stabilisation system correcting movement that is not there.
A long exposure records everything that happens during it, including the parts you did not intend.
The order worth eliminating
- Your hand. Use a remote release or the self-timer; pressing a shutter button moves the camera at the exact moment it matters.
- The shutter itself. Mirror and shutter movement put an impulse into the support. Where a body publishes an electronic or delayed mode, that is what it is for.
- Stabilisation. On a rigid support it may be correcting noise. No title in this catalogue names a measurement protocol for it, so a published stop count is a number rather than a measurement.
- The support. A tripod at its last thin section is at its least stiff, and wind loads it dynamically — which no declared maximum load describes.
What is not making them soft
The pixel count, the sensor format, and the filter on the front — unless it is a thick mount vignetting the corners, which is a different fault with a different look.
The test that isolates it
Two frames, same settings, one with the camera touched and one with a timer. If the second is sharp, the cause was contact. If neither is, work down the list — the support and the shutter are the next two, in that order.
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
Should stabilisation be off on a tripod?
Read what the maker publishes for that system. Some detect a tripod and adjust; older designs can act on their own residual signal and introduce the very movement they exist to remove. Where the documentation is silent, switching it off costs nothing and removes the variable.
How do I avoid touching the camera at all?
A remote release, a self-timer, or the body’s own delay. This catalogue keeps remote shutter releases as their own family, and the published figures on them are range and whether they are wired or wireless — not their effect on sharpness, which is why it goes unsaid.
Last reviewed 12 September 2026