Built-in mic

pros.

• Always at hand
• No separate equipment needed
• No extra person needed.

 cons.

• Picks up all sounds of camera (focusing)
• Picks up all sounds from the cameraman
• Sound quality
  • poor stereo separation
  • noise
  • poor intelligibility

separate mic

One or more separate mics can cancel all cons mentioned above.

Professionals use separate mics with a separate mixer and recorder. Only during editing the sound is added to the footage.

With this method however, the advantages of the built-in mic are lost.

Best of both worlds

Use a separate shotgun mic mounted on the camera.

• Less unwanted sounds of the camera and cameraman
• Better sound quality than the built-in mic.