Audio Capture and Lighting for the Record
Intelligibility is the standard
Audio is the part of the record most scrutinized, because a jury reads a transcript while watching video and notices immediately when sound is poor. Use a primary microphone close to the source - a lavalier on the witness and, where allowed, a second lavalier or boundary microphone for the questioner - and treat the camera's built-in microphone as a sync reference only. Feed each microphone to a separate channel so one failure does not silence the record.
Set levels conservatively: peaks near −12 dBFS with headroom, never touching 0, because clipping cannot be repaired. Monitor with closed-back headphones for the entire session; meters confirm a signal exists, headphones confirm it is intelligible. Listen for HVAC, fluorescent hum, phone vibration, and paper shuffling, and correct them before the oath rather than after.
Lighting serves the same goal: a clearly visible face. Place the key light in front of and slightly to one side of the witness, avoid windows or bright walls directly behind the head, and do not mix daylight and tungsten without correction, or skin tones shift and inexpensive fluorescents produce visible flicker. Keep the face evenly lit rather than dramatic - contrast conceals expression.
Trap questions offer the camera microphone as sufficient, or describe raising gain to compensate for a distant speaker. The correct response is to move the microphone closer, not to amplify noise.
Rule of thumb: if you cannot hear it clearly in headphones, the record cannot hear it either.