Enrico Marega Interactive photography course
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Focusing: AF-S, AF-C and AF areas

Autofocus has to answer two questions: where to focus, and what to do if the subject moves. The AF areas answer the first, the AF-S and AF-C modes the second.

1Simulator

AF-S or AF-C

Press Start: I walk towards the camera. With AF-S the focus stays where you locked it, with AF-C it follows me.

2Simulator

Where it focuses

Choose the AF area. With the single point, tap the photo to decide where to focus.

When to use what

1Simulator AF-S (single) focuses once and locks for as long as you keep the shutter button half-pressed: perfect for still subjects. AF-C (continuous) keeps adjusting the focus: you need it for people walking, sport, animals.

Every brand has its own names. Single is AF-S on Nikon and Sony, One-Shot on Canon and S on the Fujifilm focus mode selector; on the Ricoh GR it’s the normal autofocus mode (Select AF, for example). Continuous is AF-C on Nikon and Sony, Servo AF on Canon (AI Servo on DSLRs), C on Fujifilm and Continuous AF on the Ricoh GR IV.

2Simulator The areas decide where to look. The single point is the most precise, but you move it yourself. Auto area chooses on its own, often the nearest or most contrasty object, and it can get it wrong. Face and eye detection, which almost all recent Nikon, Canon, Sony, Fujifilm and Ricoh cameras have, is the best choice for portraits.

Key points

  • AF-S (One-Shot on Canon) for still subjects, AF-C (Servo on Canon) for moving subjects.
  • Auto area tends to pick whatever is closest: always check where the box lights up.
  • In portraits, focus on the nearest eye: if it’s sharp, the photo looks sharp.

Try it yourself

Ask someone to walk towards you and shoot a burst, once in AF-S and once in AF-C. Count how many photos are in focus in each series.

Post the result and tag me @enrico.marega, or send it to me by DM: I’d love to see how you tackled it.

Quick check

A child is running towards you. Which mode do you use?
In auto area the camera has focused on the railing in the foreground instead of the person. What do you do?