Examples, ISO 100, ISO 200, ISO 400, ISO 3200, ISO 6400.

Map the triangle.

Imagine a bucket that must collect enough water.

You can fill it by bigger hole, voucher, longer time shutter,

amplifying what's collected so.

That's all photography is.

Every exposure is a compromise.

Real example, Anna running in the dark.

You need fast shutter.

So, shutter 1-1000, aperture F2, ISO 400 instead of shutter 130, aperture F8, ISO 100

because the second image will blur.

NACA iPhone exercise open camera.

Photograph exactly the same object three times.

Photo 1, bright sunshine.

Photo 2, indoors near a window.

Photo 3, dim room.

Then 1, open each photo.

2, swipe up or tap the 3.

3, look at ISO, aperture, shutter speed.

You'll see the iPhone automatically changing the settings.

That's the first step towards thinking like a camera.