The principle
Changing from ISO 100 to ISO 200 is one stop. At the same aperture, the exposure time can be halved for comparable image brightness: for example from 1/125 to 1/250 second.
CAMERA BASICS · PHOTO & VIDEO
Understand ISO.
Choose exposure deliberately.
100, 200, 400, 800: ISO values form a sequence of doublings. This short video explains how the steps relate to aperture and exposure time.
Read the English summary
Doubling or halving an ISO value corresponds to one stop. This lets you coordinate ISO, shutter speed and aperture within the exposure triangle.
APPLY IT TO YOUR SETUP
One stop. Three controls.
For photographs
Check the light on the subject and the depth of field you need first. Compare test images at the intended output size rather than assuming a universal ISO limit.
For video
Frame rate, motion rendering and the camera profile are part of the decision. Record the tested combination of lighting, aperture, shutter speed and ISO for recurring sessions.
For your notes
Keep a reference image and record camera, profile and settings. Check the result again when the subject or lighting changes.
Further reading: Nikon on ISO sensitivity and exposure stops.
LEARN ON YOUR OWN CAMERA
Practise the settings together.
On the practice day you work through capture using your subjects and equipment, with a checklist to help the next session.
Enquire about a date