Focus peaking

Switch peaking on and high-contrast edges that are sharp get a coloured fringe, usually red, blue or yellow, updating live as you turn the focus ring. It is the fastest way to nail manual focus on a small screen where your eye alone cannot tell. Two things catch people out. Peaking keys off contrast, so a low-contrast subject in soft light can look unfocused when it is fine, and a heavily textured background can light up while the face stays soft. The sensitivity setting matters more than the colour, and turning it down usually gives a more honest reading than turning it up.