key concept Zones and tones

Us spot metering mode to explore exposure values…

Working out the exposure for a scene often means looking at different areas individually, and that’s where spot metering mode is so useful. It’s linked to the active autofocus point, so the simplest way to use it is to set the camera to single-point AF mode and choose the centre AF point. Now, with the AF point over your subject, as you adjust the shutter speed and lens aperture settings, you’ll see the marker move along the exposure bar. You don’t have to move it to the centre; for intentionally lighter or darker results, you can use an offset to give you the exposure you want.