Definition
What is ISO in video?
ISO is the sensitivity setting used by many digital cameras to describe how the recorded image is amplified or interpreted. Raising ISO can make footage appear brighter, but it may increase noise or reduce usable highlight headroom depending on the camera and recording mode.
Digital cameras do not become physically more light-sensitive in the same simple way that film stocks changed. Each camera has one or more base or native ISO settings where its sensor and processing deliver a preferred balance of noise and latitude; the behavior above and below those settings varies by model.
ISO should be chosen with exposure tools such as waveform, false color, and a calibrated monitor, not solely by the brightness of a display. If more light is available, adding light, opening aperture, or slowing a permitted shutter may produce a cleaner result than simply raising ISO.
Example in the edit
In a dim interview location, the operator first adds a soft key light, then selects the camera’s higher native ISO and checks the waveform before raising ISO further.
Why editors use it
ISO choices affect noise, highlight retention, and grading flexibility, so they must be made for the specific camera and scene rather than treated as a universal brightness slider.
Quick answers
Frequently asked questions about ISO
Does a higher ISO always create more noise?
Often it can, but the exact behavior depends on the camera, its native ISO modes, recording format, and exposure quality.
Is ISO the same as exposure?
No. ISO is one camera setting involved in achieving a desired exposure; aperture, shutter time, light, and ND filtration also matter.
What is native ISO?
It is a camera’s preferred sensitivity setting, or one of several such settings, where its sensor and processing are designed to perform especially well.