NAB 2012-Booth Seminars: Mics for DSLR Cameras 1

Transcription

1 1 MICROPHONE TECHNIQUES For DSLR Cameras AUDIO CONSIDERATIONS FOR DSLR CAMERAS DSLR Cameras are designed for image capture Audio is secondary to picture Small internal microphone 1/8 audio input connections No provisions for phantom power Automatic gain/level controls Minimal to no metering No headphone monitoring Canon DSLR s are now incorporating desired audio functions Metering Manual level control DISTANCE FACTOR SIGNAL TO NOISE Distance Factor The further the sound source is from a microphone, the lower the sound is at the microphone Signal to Noise Signal is the desired sound source. Noise is everything else. Expressed in a ratio

2 2 WHY CHOOSE EXTERNAL MICROPHONES Internal camera mics - too far from action Internal mics typically are not high performance mics Susceptible to camera noise pickup Can pick up camera operator talking A DSLR with a long lens can see further than the microphone can hear Microphone options: External microphone attached to camera Shotgun microphone on a boom pole Lavalier microphone on subject BOOM MICS PATTERN SELECTION Narrow pattern shotgun Greater reach More off-axis rejection Will not bring talent closer More reverberation in closed interior Cuing on talent more critical Watch pickup of sound behind talent Aim up or down, not parallel to ground Wider pattern - cardioid, cardioid Better for indoors Shorter effective range Smaller mic, easier to place in shot Take advantage of pattern Balance strong to weak voice by mic position Favor weak voice on-axis, let strong voice strike slightly off-axis BOOM MIC SELECTIONS Long shotgun (AT815b) Outdoors, wide shots, more distance Short shotgun (AT897) Outdoors, close shots, run and gun Indoors - high ceilings Hypercardioid (AT8033) Indoors most situations Tight quarters These microphones can operate on a battery as well as phantom power

3 3 BOOM MICS MOUNTING CHOICES Shock mount minimizes pick up of mechanical and boom operator handling noise AT8415 Shock Mount Proper mic insertion Over/under on bands Fits boom pole (3/8 threads) and mic stands AT8471 Isolation mount Locks on to mic Less isolation Fits mic stands K-Tek KGPSS Mic Mount Smaller profile Locking swivel adjustment BOOM MICS - WINDSCREENS Help to minimize effects of wind and air movement across the mic Use foam windscreen indoors Use fuzzy windscreen outdoors In a pinch... Consider using other items to block wind LAVALIER MICROPHONES Microphone worn by talent Gets microphone close to sound source Helps control unwanted background noise Mic can be visible or hidden These microphones can operate on a battery as well as phantom power

4 4 LAVALIER MICS - CHARACTERISTICS Proximity Lav Work best when close to sound source Emphasizes voice news-man s sound Less sensitive to background sound and noise Volume change vs. distance is more pronounced Ideal for applications where active sound reinforcement is used Transparent Lav Sound is more open like omnidirectional studio mic More sensitive to background sound and noise Sound is more natural and less forced Can be deployed at greater distances Volume vs. distance characteristics more gradual Intercut easier with boom mic sound RIGGING AND WEARING LAV MICS OUTSIDE CLOTHING Use proper clip Tie clip Viper clip Magnetic clip Attach mic to center chest opening in shirt or blouse or jacket lapel Place mic on side that talent most often turns toward Cover mic with white camera tape and color with markers to match wardrobe Dress cable under clothing Hide power supply/module in clothing or pocket Broadcast loop dressing mic on clip RIGGING AND WEARING LAV MICS UNDER CLOTHING Clothing noise Contact Clothing physically rubbing against mic or cable Acoustic Clothing rubbing against itself Under clothing microphone mounting techniques Secure cable with loop of tape Secure microphone capsule with tape triangles Secure cable to clothing with tape Moleskin strips and safety pin

5 5 CAPTURING AUDIO GETTING IT INTO THE CAMERA Single System Recording Audio is recorded directly to the camera External audio input connection is used Field Mixer (person) is linked to camera Update firmware to allow for manual level control Dual System Recording Audio is recorded to independent recording device On-camera mic is used to capture scratch audio for synchronization Field Mixer (person) and camera do not have to be linked Both methods have advantages and disadvantages CONNECTING TO DSLR DIRECTLY Most DSLR cameras have 1/8 TRS Input Microphone level input signal Stereo (L+R) No power for microphones Defeat AGC with updated firmware Audio-Technica Pro24CM Stereo Microphone Dual cardioid condenser elements Designed to attach to a camera Output 1/8 TRS right-angle plug Battery powered Includes windscreen, shoe-mount shock isolation mount Audio-Technica AT2022 Stereo Microphone Dual cardioid condenser elements Elements swivel (90 or 120 pickup pattern) Output 1/8 TRS right-angle plug Battery powered Includes windscreen, stand clamp CONNECTING MICROPHONES TO 3.5 MM STEREO TRS Single 3-pin XLR-F to 1/8 TRS XLR pin 2 connects to Tip XLR pin 3 connects to Ring XLR Pin 1 connect to Shield Audio is unbalanced Included with AT2022 Stereo Microphone Do NOT use with a mono microphone! Ring - Right Tip - Left Sleeve Common both channels Although both adapters look the same, electrically they are completely different!

6 6 CONNECTING MONO MICROPHONE TO STEREO TRS Single XLR-F to 1/8 TRS XLR pin 2 connects to BOTH Ring and Tip XLR Pin 1 & 3 connect to Shield This unbalances the microphone but both channels are in phase Allows a mono microphone to feed both camera channels Pin 1 - Sleeve Pin 3 - Sleeve Pin 2 Both Left + & Right + Ring - Right Tip - Left Sleeve Common both channels CONNECTING TWO MONO MICROPHONES TO STEREO TRS Two XLR-F to 1/8 TRS First XLR pin 2 connects to Ring (Right) Second XLR pin 2 Connects to Tip (Left) Both XLR s pins 1 & 3 connect to Shield This unbalances both microphones but channels are in phase Allows a separate microphone to feed each camera channel Pin 1 - Sleeve Pin 3 - Sleeve Pin 2 Left + Pin 1 - Sleeve Pin 3 - Sleeve Pin 2 Right + Tip - Left Sleeve - Common both channels Ring - Right STEREO MICROPHONES OUTPUT CONNECTIONS 5-pin XLRF-type connector Balanced low-impedance Fan-out at equipment end to dual 3-pin XLRM-type connectors Color coded Gray Left channel Red Right channel Microphones typically requires phantom power on both 3-pin XLRM connectors Pin 1 Sleeve Pin 2 Left + Pin 3 Left - Pin 4 Right + Pin 5 Right Right Left ground

7 7 CONNECTING STEREO MICROPHONES TO 3.5 MM STEREO TRS Single 5-pin XLR-F to 1/8 TRS XLR Pin 1 is common Shield XLR Pin 2 & 3 balanced audio (Left Ch) XLR Pin 4 & 5 balanced audio (Right Ch) This adapter unbalances the audio Pins 2 & 3 Tip Pins 4 & 5 Ring Included with AT8022 Pin 1 Sleeve Pin 2 Left Pin 3 Sleeve Pin 4 Right Pin 5 - Sleeve Ring - Right Tip - Left Sleeve Common both channels PHANTOM POWER DC voltage applied across a balanced line to power microphone s electronics Delivered on same two conductor shielded cable used to carry the audio signal Works with balanced line only Voltage appears across signal leads and shield Voltage ranges from 9 52V DC 48 Volt most common Sources for phantom power Camera, mixer, preamp or other device External power supply Battery in microphone (not true phantom power) 48 V DC ground THIS IS NOT PHANTOM POWER SMOKIN HOT microphone power adapter Hmm, that mic worked great, right before I plugged it in Makes cheap microphones sound more expensive and expensive mics sound really HOT! Wahoo's everywhere know that More power is better! So, why settle for a measly 48 V when you can get a full 120V right out of the wall. Just plug it in and your mics will be cookin, for a really HOT session. Only $9.99 ($22.00 west of the Mississippi) Order yours online today. Not available in stores. Disclaimer: Unprofessional use only, Not responsible for misuse. Keep small children and talent away at all times. Wear protective clothing, always use proper protective eyewear. Do not use in wet conditions. Downloadable version only. Hum specs not available.

8 8 SINGLE SYSTEM RECORDING USING INTERFACE BOX Lav Mic on Talent Mono Shotgun (AT897) (Use battery) Lav Mic Power Module (Use battery) Alternately an AT8022 Stereo Microphone can be used Direct (TRS) Connection to camera Basic passive interface box provides transformer isolation, and some level control SINGLE SYSTEM RECORDING USING DSLR ACTIVE INTERFACE BOX DSLR Interface Box designed specifically for use with DSLRs Has two mic inputs with level controls Phantom power Method to defeat AGC Shotgun (on boom) Direct (TRS) Connection to camera Lav Mic on Talent Lav Mic Power Module DXA-SLR interface Beachtek Don t forget headphones for audio monitoring SINGLE SYSTEM RECORDING USING MIXER Mixer provides phantom power, active gain stage, lower noise Has two mic inputs with level control Phantom power Monitoring Shotgun (on boom) Lav Mic on Talent Mixer Unit (MP2) Direct (TRS) Connection to camera Lav Mic Power Module Don t forget headphones for audio monitoring

9 9 DUAL SYSTEM RECORDING Mics connect to secondary recording device Use Clapper or some other pulse noise to sync Internal or External mic on Camera (Scratch Audio) Shotgun (on boom) Lav mic on talent Lav Mic Power Module Don t forget headphones for audio monitoring DUAL SYSTEM RECORDING USING MIXER UNIT Allows multiple mics to be used Gives soundmixer operator more control Internal or External mic on Camera (Scratch Audio) Shotgun (on boom) Mixer Unit (SD-552) Talent Lav Mic #1 Talent Lav Mic #2 Don t forget headphones for audio monitoring CONNECTING TO STEREO TRS Interface Box (BeachTek) Provides proper match (impedance) for professional mics Maintains balanced audio to microphones Provides some attenuation or level control for each input Can provide phantom power for condenser microphones Selectable single input to both channels or one-to-one input to specific channel Some are active (battery powered), some are passive Attaches to camera via tripod screw

10 10 CONNECTING TO STEREO TRS Portable Field Mixer (Direct Output) Mixer allows multiple microphones and mixing them Use TRS Tape output to connect to the camera Can be used with wireless (Camera Hop) or umbilical cable Extensive inputs/output connections Very low noise operation Slate mic, visual monitoring, headphone output Mounts separately from camera ADVANCED SETUP Wireless Camera Hop Uses ATW-1800 Series wireless to hop audio signal from mixer to camera Eliminates need for umbilical (break-away cable) Allows soundmixer and camera to roam freely Shotgun (on boom) Lav Mic on Talent Lav Mic on Talent THANKS FOR ATTENDING Come back for our other sessions: Microphone Techniques for Episodic Television and Features Rigging Lavaliers and Wireless Microphones for Film and Video Production Recording live music for broadcast Mid-side / stereo miking demystified