2

I am using Nikon D5100. To shoot a subject which is:

  1. Stationary:
    • we can set AF-area mode to Single Point AF
    • we can set Focus mode to AF-S
  2. Moving:
    • we can set AF-area mode to Dynamic-Area AF
    • we can set Focus mode to AF-C
  3. Or we can set both AF-area and Focus mode to Auto-area AF and AF-A

These settings for AF-area mode and Focus mode look similar to me. I am not able to make out a difference between these two. What if the camera only has AF-area mode and no Focus mode?

Please let me know what I am missing here.

Thanks.

7

Short Answer: Focus mode is how the camera focus while the AF-area is where the camera focus.

Focus modes

  • AF-S/One Shot AF - Find focus only once while the release button is half-pressed
  • AF-C/AI Servo AF - Find focus until the release button is fully pressed or released
  • AF-A/AI Focus AF - Let the camera decide if it should use AF-S or AF-C
  • MF - The photographer decide the focus manually

AF Area

  • Single point - Focus mainly on the selected point
  • Dynamic-Area - Focus on the selected point and the area around it in case of movement
  • Auto-area - Camera decide where it should focus on
  • 3D-tracking - A better tracking of objects in motion. (Not all cameras have this mode)

For a bit more detailed answer on AF Area you could check the answer from the question: When to use a particular auto-focus mode

  • Auto Area AF seems to imply face detection according to Nikon's materials – Imre Jan 27 '14 at 12:04
  • There is no face detection in D5100 in the through-the-lens mode (the OP uses that for focusing). Face detection is only available in LiveView (and I have not yet seen any camera actually that does face detection through the lens). – TFuto Jan 27 '14 at 12:45
3

In AF-S, you can use

  • Single-point AF (you select a fixed focus point)
  • Auto-area AF (camera selects focus point automatically)

When focus is acquired, there is no more focus tracking.

In AF-C and AF-A, you have

  • Single-point AF (you select a fixed focus point)
  • Dynamic-area AF (you select a fixed focus point, camera tries to stay in focus by using nearby focusing points as well)
  • 3D-tracking (you select the subject by a focus point, camera tries to track that subject)
  • Auto-area AF (camera selects focus point automatically)

The camera is adjusting focus as the subject or your camera moves.

Note that AF-A can switch to AF-S or AF-C when in Single-point AF or in Auto-area AF!

So the total combinations are:

  • 2 in AF-S
  • 4 in AF-C
  • 4 in AF-A with the flavor that it can select AF-S or AF-C in two modes.

I hope this answer your question.

For more information, see the D5100's User Manual page 32 for TTL focus, page 44 for LiveView focus.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.