XL1 AUDIO GUIDE
Digital Audio Recording
CANON DIGITAL AUDIO RECORDING
Canon’s XL1 records in the (relatively) new DV format. This format makes for greatly expanded audio capabilities because of its use of Pulse Code Modulation (PCM).
Æthis type of recording differs from analogue recording where sound waves are recorded as changes in the magnetic field on the tape.
Æwith digital audio recording, sound is recorded as a 0 or 1, which is then converted to a pulse code. [binary vibe].
SOUND WAVES
‐Sound waves = vibrations in the air; 2 properties:
ÆThe frequency goes from bass (low) to treble (high) and refers to the number of times per second the wave goes through a cycle. The more cycles per second, the higher the frequency
ÆThe amplitude goes from soft to loud and refers to the swing of the curve. The further the curve swings above or below the centre line, the louder the signal.
[together frequency + amplitude make up the sine wave]
‐The average ear processes 20 (20Hz) to 20 000 cycles per second.
Æthe wavelength becomes shorter as the frequency rises
HOW THE CAMERA PROCESSES DIGITAL SOUND
Æ
Sound
mic | Æ analogue signal Æ A/D Converter |
Camera
The camera picks up an analogue signal and uses an Analogue‐to‐Digital (A/D) converter.
For playback, the sound is processed through a Digital‐to‐Analogue (D/A) converter.
QUALITY
‐Digital systems measure in steps, but the analogue signals they’re measuring are continuous.