ISO
Also known as: sensor gain, ISO sensitivity
ISO sets how much a camera amplifies its sensor signal. Higher ISO brightens dark scenes but adds visible noise, especially on small action-camera sensors.
Updated
What it means
In a digital camera, ISO is gain applied to the sensor signal. It does not make the sensor collect more light - it amplifies what was captured, random noise included. Low values like 100 give clean images, and each doubling of ISO brightens the picture by one stop while making noise more visible.
Action cameras and small drones have tiny sensors, so noise shows up early. Footage that looks clean at ISO 100 to 400 can turn grainy and smeary by 1600 or 3200, where in-camera noise reduction starts erasing fine detail like grass, snow texture and hair. Along with shutter speed, ISO is the main exposure control on cameras with a fixed aperture.
How it works in practice
In auto mode, cameras raise ISO as light drops. GoPro lets you set ISO Min and ISO Max in its Protune settings, which is one of the most useful controls on the camera: capping ISO Max at 800 or 1600 for dusk riding keeps noise in check at the expense of a darker image.
Drone pilots usually fix ISO at the lowest value and control brightness with ND filters instead. On many cameras a Log profile such as D-Log M has a higher minimum ISO than the standard color mode, so check what your model allows before planning exposure for a bright day.
What to watch out for
Night and indoor footage is where ISO bites. A camera that hits its ISO ceiling will also slow the shutter, so you get noise and motion blur together. Add light, slow down, or accept a darker clip rather than letting ISO run all the way to the maximum.
Underexposing at low ISO and brightening later is not a free fix either - small-sensor footage, especially 8-bit H.264, falls apart in the shadows when pushed. High frame rates add pressure too: 240 fps forces a very short exposure, so slow motion in dim light almost always means high ISO and visible grain.
How RawClip handles it
ISO is baked in at the camera, so get exposure right while shooting. RawClip picks moments by motion, jumps, faces and peak action across all your uploads, removes dull and duplicate footage, and cuts the strongest parts into one highlight.