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Jim Krause | Classes | P351 Video Field & Post Production

Summer 2018 Week 2 - Wednesday Lab


  • Lab today: Audio & intro to field lighting with reflectors.
  • Carry out Audio / News Exercise. The assignment is due by Friday. Thursday) we'll do a Motion Graphics Exercise.
  • Next week we'll have a Midterm quiz Tuesday and then screen your Art Videos. Wednesday we'll carry out a lighting/portraiture exercise. Thursday is dedicated for you to shoot your interview/feature stories.

SOUND - (Readings: Cybercollege units 37, 38, 39 & 40)


  • Introduction
  • Loudness & Frequency
  • Types of microphones and their application
  • Signals & metering
  • Examples (music, close up miking, long shot miking, ambience etc)
  • Lab assignment:


Audio for film and video is more than just recording a good signal. Most soundtracks are multi-layered creations that go far beyond providing us with dialogue from our performers. We hear cues that tell us where they are- outside, inside, what the weather is like, how big the room or environment is, if there is someone sneaking up on them, etc.

When done right the audience doesn't even notice the soundtrack - But even so it's adding an important layer of information.

Audio is an important tool used to motivate edits. (Cutting to the beat in a music video for example.)

Plan time in your production schedule for sound design. Make it an integral part of your planning & production.

Keep it legal! - If you need backgrounds or sound effects for your production you have a few choices. Whatever you do, make sure your soundtrack has legal integrity.

Loudness & Frequency

Loudness can be measured in decibels (dBs) and be represented visually with VU meters.

Test tone & Average Dialog Levels

Test tone - Common practice is to use a 1 kHz reference tone along with color bars (before the start of a program or live feed). Most editing software can generate this along with color bars.

Average Dialog Levels (ADL) - The maximum peak level for digital audio is 0 db. Anything over is clipped (not good). Production standards for average dialog levels vary. Most PBS stations require -20, but other broadcasters might use -12. Check with the broadcaster or production house to determine delivery specifications. It's common practice to normalize peaks to a higher level for web distribution. It's easy to change the overall track level by using the Track Mixer.

AGC - Automatic gain control circuits try to get a consistent level. If it’s soft, it’ll boost the signal. If it’s loud it’ll turn it down. Don’t use it! It’ll bring the noise floor up and reduce your dynamic range.

Frequency is measured in Hertz or cycles per second

  • Hertz = CPS cycles per second
  • Kilohertz (kHz) = 1000 Hertz
  • Human hearing generally ranges from 20 Hz to 20 kHz
  • Concert A = 440 Hz
  • Middle C is 261.63 Hz
  • The human voice ranges from about 100 – 9,000 Hz

Electrical Characteristics:

Dynamic - Works opposite of a speaker. A wire coil attached to a diaphragm is suspended inside a magnetic field. Sound waves hit the diaphragm making the coil move. This creates a flow of electricity in the coil windings. Dynamic microphones are typically durable and a good choice for hand held vocals or percussion instruments.

Condenser - (a.k.a. electret or capacitor)- Need batteries or phantom power to operate. A plate or diaphragm moves adjacent to a stationary, charged backplate. The capacitance between the two plates changes as the diaphragm moves modulating an electric current. This current must be boosted by a preamplifier to create a usable signal.

Condenser microphones are more sensitive than dynamic microphones and due to their preamplifers, output a signal with more gain. They are a better choice for distant miking and lower level sound sources. Most full range, high-quality studio microphones are condensers.

Ribbon - A small (extremely delicate) metal ribbon is suspended inside a magnetic field. Sound waves move the ribbon, creating an electrical flow. Because of their delicate construction, ribbon microphones are not suitable for windy conditions or extremely loud sound sources. They are typically only used for vocal applications. (The RCA mike on Johnny Carson’s desk was a ribbon microphone)

Pickup patterns:

  • Omni (EV635 is a commonly found dynamic mike. Most lavaliere microphones are condensers and have omni-directional pickup patterns)
  • Cardioid (dynamic cardioids include SM57, SM58 & the RE20. Condenser cardioids include AKGC100, AT4033)
  • Hyper-cardioid (Shotgun microphones- almost all are condensers)
  • Figure eight (All ribbon microphones. The U87 & AKG414 are switchable between Cardioid and figure eight)
  • Other:
    • Boundary or Pressure Zone Microphones (PZM) are flat and designed to be placed on a flat surface. Their pickup pattern resembles half of a sphere.
    • Contact microphones are small and designed to be mounted directly onto a resonating object. (Onto the bridge of a cello or the inside of a guitar) These are used mostly for music.


  • Lavaliere - Very popular for film & video. Provide a consistent sound close to the source and are inconspicuous. Wireless versions of these are a must have for professional videographers.
  • Hand held – try to avoid using these unless you’re doing interviews with people on the street (an assistant with a boom would be better). When using, make sure to keep them a consistent distance from the source. Best used on a stand.
  • Stands (floor & desk) obtrusive good for music; desk: obtrusive but an excellent way to hold a microphone (Leno, Letterman)
  • Boom – handheld and floor stand models (typically used with a shotgun mike)
  • Headset – Conspicuous but provide audio monitoring for performers and a consistent sound source. (Used frequently for live sporting events and by singers)
  • Parabolic mount. A large bowl with handles on the outside and a microphone mount on the inside. Place a microphone in the middle and you have a highly directional microphone- more directional and sensitive than a shotgun mike. Commonly used for sporting events and spying, be sure you faithfully listen to the headphone while using. You need to move these continuously to keep them focused.

Signals, cables and connectors

Digital vs Analog

Most of todays AV gear has digital inputs and outputs (HDMI, DVI-D, USB, etc.). However many signals still need to come from or be sent to devices via analog connectors (microphones, speakers, etc.).

Mic / Line Level - Analog audio signals are typically either line level or mic level.

Cables: Balanced vs. Unbalanced - Analog audio cables are either balanced or unbalanced

Balanced cables have three wires (two conductors & a ground) and are far less prone to electrical interference than unbalanced (2-wire) cables. Long cable runs of unbalanced cables will also cause a loss in high frequencies.

Cables with 3-pin XLR connectors on the ends (like mike cables) are balanced. They have three wires- two conductors and a ground.

Know how to properly wrap cables! You need to know this in order to work professionally- really. Ask me in lab if you need a refresher.

Wireless microphones - Diversity vs. Non-Diversity - Diversity receivers have two antennas.

Jim's Audio Production Tips:

  • In general, lavaliere (wired & wireless) and shotgun microphones are the most usfeul mics in video/film field production. These are the mic you'll commonly use for interviews and capturing dramatic scenes. Desktop (stand-mounted) and handheld microphones can also be useful- mainly when you have folks at a table or podium- or when someone needs to hold a microphone.
  • Get some good headphones! - I like having a few good pairs - totally enclosed and bud-type (noise-cancelling is a nice feature)
  • Faithfully monitor your audio with headphones while shooting and make sure your levels are in the proper range. Listen to both tracks for drop-outs, popped Ps or Ts, and any other distortion. Record a little and play it back. If you are in a noisy environment, go to somewhere where you can hear it.
  • When shooting interviews you can use one track for your subject and the other for either your interviewer or NAT sound from the camera.
  • Never use AGC unless you have no other option (shooting breaking news, covering a fire, etc.). An alternate method is to set one channel 6dB below the other.
  • When shooting B-roll or any video, always record audio- even if you don't think you need it.
  • DSLR/film shooters: When you're shooting sound with a separate audio recorder always slate or clap to establish a synch reference. If you need to synch audio tracks in post PluralEyes by Singular software might be useful.
  • On location, always record some ambient audio with the same microphone you are recording your interview with. (Often called room tone.) This can be layered into the soundtrack during post. If you need to add some dialog to a scene, you’ll have a background bed to lay under it.
  • When scouting shooting locations listen. Is it quiet enough? (vehicle noise, construction, etc.) You need to make sure to not record unwanted sounds or copyrighted music in the background.
  • Are you taping a person in the field and also recording voice overs? If so, use the same microphone in the same manner. This way the audio will match.

FYI The Production Lab has the following tools which might be useful:

  • Mic stands (& C stands)
  • microphones
  • field mixers
  • field recorders
  • slates

Portraiture Lighting recap

  • Framing/composition
  • Lighting


These should be in every photographer/videographer's gear bag. Look at samples:


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