Crop factor
Also known as: focal length multiplier, sensor crop
How much smaller a sensor is than full-frame 35 mm, expressed as a multiplier. It tells you how a lens on that camera compares in field of view.
Updated
What it means
Photographers describe lenses by focal length, and those numbers were defined for 35 mm film. A smaller sensor sees only the middle part of what a lens projects, so the same lens gives a tighter view. The crop factor is the ratio between a full-frame diagonal and the smaller sensor diagonal, for example 1.5 for many APS-C cameras or much more for action cameras.
Spec sheets often quote an equivalent focal length, such as 16 mm equivalent for an action cam lens that is physically a few millimeters long. That equivalent number is the real focal length multiplied by the crop factor, and it is the easiest way to compare field of view across cameras.
How it works in practice
Crop factor also appears in video for a second reason: some modes use only part of the sensor. Shooting 4K on a camera with a larger native area, turning on stabilization, or choosing a high frame rate can add an extra crop, so the image looks tighter than the lens would suggest.
When you plan a multi-camera shoot, crop factor helps you match angles. Knowing that a drone lens equals roughly 24 mm and your action camera is closer to 14 mm explains why the same scene feels so different between the two, and helps you decide which digital zoom or punch-in to use when matching shots.
What to watch out for
Equivalent focal length describes framing, not light gathering or depth of field. A small-sensor camera with a lens equivalent to 24 mm still behaves like a small sensor in low light, so do not expect full-frame noise performance from the number alone.
Marketing also mixes conventions. Some brands quote the field of view in degrees, others the equivalent focal length, and some quote the widest mode only. Check which lens mode a figure refers to before comparing two cameras, or you may pick a model that is much tighter than you wanted for helmet POV.
How RawClip handles it
RawClip does not change framing or lens geometry. Footage from cameras with different crop factors can go into one order, and the AI combines the wide action shots and tighter angles into a single highlight.