Location Audio Equipment

Transcription

1 INDUCTION PACK Location Audio Equipment Location Recording Page 1

2 GROUND RULES Location Audio Induction Pack 1 Requests for equipment bookings may be made IN ADVANCE by ing: sacs-tech@ncl.ac.uk Equipment should be collected during the opening times below 2 An induction MUST be completed before you will be allowed to hire the equipment. 3 All equipment is booked out on the understanding that the borrower carries full risk for the entire replacement cost of lost equipment and the entire repair costs of any damaged equipment. 4 Equipment may only be signed out and returned between the following times: Monday 10.30am to 12noon Wednesday 2.30pm to 4pm Friday 2.30pm to 4pm Anyone arriving outside of these times WILL be turned away. 5 You should check that you have all accessories, the batteries are charged and that the equipment works as expected when signing out and report any faults or missing items immediately to: sacs-tech@ncl.ac.uk 6 All equipment must be returned with the designated accessories, with batteries charged and media erased. Equipment returned late or with accessories missing will incur a fee of 5 per day. 7 Any borrower failing to return equipment on time on more than three occasions will be barred from borrowing further equipment for the remaining part of the academic year. Page 2

3 Staff Location Audio Induction Pack If you are experiencing technical difficulties that are not covered in this document, the following staff are here to help: o o o o John Ayers SACS Studio Manager Tel: , j.d.ayers@ncl.ac.uk Richard Bate Digital Media Technician Tel: , richard.bate@ncl.ac.uk Neil Davidson Culture Lab Technician Tel: , neil.davidson@ncl.ac.uk Dawn Pinkerton Receptionist and Facilities co-ordinator Tel: , dawn.pinkerton@ncl.ac.uk Introduction Sound is an integral part of any film. Sound works with the images to provide narrative through speech or other sound, produce emotional involvement, add suspense etc. The secret to effective sound is in capturing a good performance faithfully at the best quality available. Some of the elements that impact on usable sound include background noise and reverb, wind noise, poor mic placement, signals recorded at the wrong level, inconsistent sound between scenes. The same amount of planning should go in to the sound capture as the image capture. Location scouting should take in to account the acoustics and background noise of a space and time should be spent working out how many microphones of what type should be used and how this will synchronise with the image capture. This induction is intended to get you up and running with the available equipment as quickly as possible. You will need to practice with microphones and mixers to improve your sound recording technique. There is not the space here for a thorough grounding in how sound works, but this knowledge is well worth investigating. For more information see the bibliography or contact a member of the technical team for advice. Page 3

4 Available equipment There are 3 main elements to capturing sound: MICROPHONES MIC PREAMPS/MIXER RECORDING MEDIUM Microphones MICROPHONES As the first element of the recording chain, microphones should be chosen and used with care. They can be though of as the lens for the sound. Some microphones are better at some jobs than others. The positioning affects the sound profoundly. Decreasing the distance between the microphone and the sound source decreases reverberation (or room sound) and other background noises and increases the amount of direct sound. Recording with a directional mic can help to increase the amount of direct sound picked up and decrease the amount of noise if the active side of the mic is pointing at the source and the null side of the mic is pointing at the noise. Microphones usually pick up in one of the following directions (polar patterns): Omnidirectional picks up sound from all directions, rejects handling noise and wind noise well. Figure of Eight picks up sound from in front and behind and rejects from the sides. Cardioid picks up sound from the front and some from the side and rejects from the rear. Hyper-Cardioid and Super-Cardioid the most directional mics, picks up sound from the front and rejects from the sides. There is a small pickup from behind the mic. (For more detail see Page 4

5 There are 5 main styles of microphone that you will be using: 1. Boom the most effective setup for capturing dialogue. Booming involves attaching the microphone to a pole, called a boompole, and suspending it in front of the subject but outside of the frame. This technique allows for considerable movement by actors and captures a natural mix of speech, sound effects and movement sounds. The boom operator should closely follow the action by moving the mic to keep the sources on mic, ensuring the dialogue is captured in the clearest manner. Knowing the script and rehearsing with the actors will help the boom op anticipate movements rather than reacting to changes. This helps with maintaining a uniform sound. Recording from overhead usually gives the most natural sound and perspective. On wider shots, the mic tends to be higher resulting in thinner, more distant sounding dialogue. On closer shots, the mic is closer, resulting in greater presence. Recording from underneath can sound more boomy (as the mic picks up more chest resonance) but can be used when there is a low ceiling or other obstacles above. The boom consists of various elements: a) The microphone - this can be of any type but a hypercardioid or shotgun mic is the most prevalent as they are very directional allowing you to zoom in on the sounds that you want and largely ignore the sounds that you don t. b) The shockmount and windshield these reduce noises caused by handling the boom pole and wind. It is essential that these accessories are fitted correctly and attached firmly to the pole. c) The boom pole these can be various lengths (our longest is 3.9m!) and can be wired internally or externally. Care should be taken when assembling and using the boom. -Make sure that all connections are tight so that no small rattles occur in operation or the mic slips from its position. -Be aware of the surroundings so that you don t walk in to anyone or hit them with the boom. -All cables should be arranged so they can move freely when required but make no sound. -The boom operator should be on the left side of the camera to allow clear communication to and from the camera operator and allow a view of the camera lens to see when the width of the shot changes. -The camera operator should let the boom op know if he is in danger of entering the shot. -Observe lighting setups and beware of shadows cast by the boom. -Wear dark, non-shiny clothes. Do not carry anything that jangles or beeps. Wear sensible non-squeaky shoes. 2. Plant a fixed mic used to record a static subject where booms are impractical. This can be a boom mic secured in one place or behind a prop or it can be a lavaliere or a boundary Page 5

6 mic hidden somewhere on the set. Make sure the subject is talking in the direction of the plant mic. If they are moving consider a boom or body attached lavaliere. 3. Lavaliere these are tiny microphones worn on the subject s body to be used where a close sound is desired or a wide shot makes a boom impractical. Lavs are used less widely than booms due to problems with perspective and contact noise. As the mic is attached to the subject the sound can feel too close. Adding a boom mic in to the mix to add ambience can make the sound more natural. To aid movement these mics are usually used with a wireless system. In fiction filming it is usual to hide the lavaliere within clothing. This can impact on the clarity of the recording by making it sound muffled and add more clothes rustle. To minimise this, secure the clothing carefully on all sides of the mic with tape. For documentary or interview filming the lav can be fixed to the outside of the clothing. 4. Handheld useful for interviews and situations where seeing the mic is not a problem. You can use a mic that you would use for boom miking with a pistolgrip shockmount or use a specific hand-held ENG (electronic news gathering) mic. ENG mics are usually omnidirectional so should be held fairly close to the subject. Omnis minimise handling and wind noise, but care should still be taken when used in windy conditions. 5. Camera-Mounted A camera-mounted mic is unable to get close to the subject and is at high risk of excessive background noise and camera vibrations. This is a last resort and should only really be used when you are filming on your own. If at all possible fix the mic to a stand nearer the subject or attach a lavaliere. Microphones are extremely sensitive and should be handled with care. Extremes of temperature and humidity can seriously impact on how the mic behaves. As with all equipment you should check that you have all the accessories when you are taking it out and when you return. Page 6

7 Microphones Available in Culture Lab Location Audio Induction Pack Microphone Polar Pattern Suggested Use/Notes Sennheiser MKH416 Hyper Cardioid compact shotgun Excellent boom mic Its excellent directivity and compact design, high consonant articulation and feedback rejection make the MKH 416 a superb all-round microphone for film, radio and television, especially for outside broadcast applications. Sennheiser ME66 Super Cardioid Long shotgun Highly directional - It is especially suitable for reporting, film and broadcast location applications and for picking up quiet signals in noisy or acoustically live environments as it discriminates against sound not emanating from the main pick-up Sennheiser MKH418-S Mid-Side stereo shotgun Ideally suited for every type of application in film, radio, television and reporting, both indoors and outdoors. Sturdy and weather resistant. Mid-Side allows you to record two channels that can be decoded to a variable width stereo image in post production or directly to the recorder. Beyerdynamic M58 n(c) Omnidirectional ENG Mic Designed for electric news gathering (ENG) and electronic field production(efp) applications. Internal shock-mount dramatically reduces handling noise, while the microphone frequency response has been tailored to provide broadcasters with a very accurate and intelligible sound. DPA Surround Microphone Compact array for recording surround sound and stereo ambience and music. Audio Technica AT8022 X/Y Stereo Mic Ideal for use with portable recorders for capturing ambience and interviews. Comes with either XLR and minijack connectors TRAM TR50 Sennheiser ME 2 Omnidirectional lavaliere mic Omnidirectional lavaliere mic High quality natural sounding lavaliere. The flat body makes it easier to conceal under clothes with a wide range of fixings. The high frequency boost compensates for muffling by clothes. Has become an industry standard mic in film and tv. Good for interviews and other wireless use Microphone Accessories: Rycote Pistol Grip with Softie & Rycote full windshield kit These are essential pieces of kit for recording outside. They will ensure that wind noise is minimised. The pistol grip and softie is quick and easy to set up, the softie just slips on the end of the mic. The full windshield should be used in more extreme weather. It is slightly fiddly to setup so I suggest viewing the videos here: Page 7

8 and practicing setting the kit up before doing any serious recording. Wireless system Wireless (radio) mics send the audio signal over the airwaves using a transmitter and receiver. Their main drawback is that they are subject to RF interference, so a wired mic should be used whenever possible. Wireless mics are helpful when the boom operator cannot get close to the action and it is impractical to run cable from a lavaliere mic. Culture Lab mainly uses Sennheiser G3 systems which are fairly simple to set up. Care should always be taken with the frequencies used. Read the manual to ensure that you know how to set this up. Licences are required for some frequencies but the ranges MHz and MHz and MHz can be used without a licence. See for full details. Spare batteries are essential for wireless mics as low batteries can cause distortion and dropouts before failing completely. Cables and Connectors Video and audio work requires lots of cables. To keep them working correctly you should always ensure that they are coiled neatly and secured with a cable tie if available. Use the over/under technique. (see or Connectors can be delicate and many only fit in a socket in a certain way. Beware of forcing connectors in to equipment, if it feels as if you have to force it it s probably in the wrong socket or oriented incorrectly. Internally wired booms have connectors on the bottom. Beware of crushing the connector when resting the boom on the floor between takes. Page 8

9 Mic Preamps/Mixers MIC PREAMPS/MIXER The preamp is the device that converts the microphone signal in to a usable line level for mixing and recording. In Culture Lab the preamps are all built in to mixers of one kind or another. A mixer allows you to monitor and control the levels of the microphones in real time without being in the way of the camera and action. Although individual mixers differ in operation, all models will require you to do the following: 1. Set the Gain gain is the amount of amplification that the preamp applies to the signal. Correctly setting a mixer gain structure is one of the most important contributors to creating a clear sound. Conversely, an improperly set gain structure is one of the leading contributors to bad sound. Set the gain too low and the signal can become faint and grainy, to high and you risk distortion. To set the gain you should have the performer rehearse their part whilst you change the Gain or Trim level settings, check the Meters and listen to the signal (usually in PFL (pre fade listening) mode). The optimum signal should be averaging around -20dB and peaking just around -12dB. Your signal should never exceed 0dB as this will cause distortion. Usually in performance, the performer will speak or play louder than in the rehearsal so you will need to keep an eye on the meter at all times. 2. Route the signal to the correct output If you have multiple microphones it is a good idea to divide them amongst the available tracks. For example, if you have 2 channels on a stereo recorder you could send lavalieres to the left channel and the boom to the right channel. This is done from the Pan control. 3. Calibrate the output if you are recording to an external recorder or camera you should send a test tone at 0dBFS and change the gains on the recorder until the signal shows 0dB on the recorder s meters. 4. Setup monitor mixes Some mixers allow you to send the main output to more than one destination. This can allow recording to a camera as well as an external audio recorder or send headphone feeds for the director, camera operator and the boom op. See individual manuals for details. Monitoring and headphones Most mixers will have at least one set of headphone outputs (some have more) for the sound mixer to monitor the mix. If other members of the team want to monitor the audio you may have to send out of the mixer to an external headphone amp. The switch marked PFL (pre-fade listening) or Solo on a mixer channel will allow you to monitor just that mic to listen for any problems. You can set up a wireless link to this if you have a spare radio mic transmitter and receiver. Culture Lab have one battery powered headphone amp and a few mains powered models which can provide up to 4 headphone mixes. Page 9

10 Available Mixers/Preamps/Recorders (not including cameras) Location Audio Induction Pack Mixer Channel summary Notes Sound Devices 302 Mixer 3 Mic/Line Inputs, 2 Outputs. Onboard M-S Matrix for channels 1&2. Weighs less than 1KG. Powered by 3 x AA batteries. Sound Devices 552 Mixer/Recorder 5 Mic/Line Inputs, 5 Direct Outputs, 2 Main Outputs. Also able to record stereo to SD cards. Powered by 4 x AA batteries. Really flexible and powerful mixer. Definitely read the manual before use! Sound Devices 744T Mixer/Recorder Tascam DR680 Recorder Zoom H4N Recorder Zoom H2 Recorder Sound Devices USBPre Soundcard 2 Mic/Line Inputs, 2 Line Inputs, 2 Outputs. Records 4 channel wavs to internal hard drive or compact flash with Firewire transfer. Reads timecode to sync with camera. Powered by L and M mount camera batteries. 6 mic inputs, 2 outputs Records 8 channels to SD Card. Ideal for surround sound recordings. Powered by 8 x AA batteries or power adapter. 2 Mic Inputs, 2 built in mics. Stereo output on minijack. 4 built in mics, mic line inputs on minijack Stereo SD Card recorder. Easy to navigate. Sound quality not as good as Sound Devices but still very usable. Can record 4 channels at once when using built in mics and external mics. Powered by 2x AA batteries. Compact and light. Can record 360 degrees to 2 channels for stereo ambiences. Quick and easy to setup. Very compact and light. Powered by 2 x AA batteries. 2 mic inputs, 2 outputs USB recording for mac or pc. High quality preamps and reliable. Powered by USB. Can also be used as external preamp for a camera. Page 10

11 Recording Medium Once the sound is how you want it you will need somewhere to store the performance. As mentioned above, some mixers have recording RECORDING MEDIUM facilities built in, with others you will have to send it to an external recording medium. This could be a camera, a digital recorder, analog tape machine or a computer. Single or double system? This decision should be made early on in your planning: should the sound be recorded to the camera (single system) or to an external recorder (double system) or both (combined single and double)? With double system you usually get better quality recordings, as on camera analog-to-digital conversion will have limited dynamic and frequency range compared to the mixer. The number of audio tracks you can record to a camera is also limited if you are using multiple mics. When using double system you will need to use find some way of synchronising the camera and audio recorder. This is usually done through using a slate usually a clapperboard type, to allow an easily synchronisable point (although software such as Pluraleyes allows a certain amount of automatic audio and picture synchronisation). On some recorders you can use timecode from the camera to synchronise the recordings (space doesn t allow for a proper explanation of timecode and framerate here see Holman 2010 Chapter 8). Double System Timecode Mic signal For the simplest type of shooting, single system is really convenient. You can either connect the microphone directly to the camera or control the audio via a mixer. Plugging straight in to the camera without a mixer will give you almost no control over the audio but is ideal for simple setup where the audio is in a controlled environment and will not be changing significantly. A mixer will allow you to ride the levels and avoid overloading the mixer as well as accommodating and routing multiple mics (obviously if you are working on your own its next to impossible to control a mixer and a camera at the same time). Single System (optional mixer) Mic signal Page 11

12 Combined systems allow you to get the best quality audio, you can record multiple tracks to a standalone multitrack recorder and send a mixdown to the camera (either via radio mic links or a cable). This gives instant usable results as well as the option of more complex postproduction. This setup also provides redundancy in case of camera faults which can lead to audio dropouts or distortion. Combined System Timecode Mixdown Mic signal Multiple tracks, mono and stereo miking. Signal routing. Most cameras and recorders allow two-channel recording. In film it is good practice to record your dialogue in mono and pan it to the centre, this avoids incongruities when the camera angle changes and the source changes position on the screen. If you are using one mono boom mic, you can route this to both L and R inputs on your camera or recorder, if you are using a combination of lavalieres and boom you would route the lavs to L and the boom to R, this is two channel mono recording not stereo recording. Stereo recording allows for more realistic spatial and depth localisation and a more spacious and complex ambient sound. There are various highly effective stereo microphone techniques; a good source of these is the book Stereo Microphone Techniques by Bruce Bartlett (1991). A simple way to capture effective stereo sound in one microphone is to use Culture Lab s Sennheiser MKH418S Mid-Side microphone. This is a special stereo microphone that outputs two signals: a Mid channel (a hypercardioid forward facing) and a Side channel (figure of eight side facing) which needs decoding in post-production (or on your mixer/recording device the Sound Devices mixers can M-S link channels). Recording M-S allows control of the width of the stereo field in postproduction and provides excellent mono-compatibility. When using stereo with mono spot mics you will need more than 2 channels to record to. For example you can record the M-S signal on channels 1 and 2 and lavalieres on channel 3 and a mono boom on channel 4. Multitrack recorders are able to route signals to different tracks as well as link and group tracks. Consult the manuals to find how this is done and always check the routing before recording. Page 12

13 Digital Audio Basics (really basic information) Location Audio Induction Pack All our recording devices are digital. This means that they convert the analogue electrical signal from the microphone in to a stream of digital information. You can specify the resolution that this happens at in terms of Bit Depth and Sampling Frequency. Bit depth refers to the number of bits used to represent the amplitude dimension of a sound the higher the bit depth the wider the dynamic range available (the range the from the quietest to the loudest sound). I would suggest always working at 24 bit where available. Sampling frequency refers to the number of measurements per second that is taken of the audio. The sample rate required is just over twice the highest audible frequency (20kHz). CD audio is recorded at 44.1kHz but most film work is recorded at 48kHz or above (96kHz is becoming more and more common with some HD work recorded at 192kHz). Needless to say the higher the bit depth and sample rate, the better the quality of the audio. Most of our equipment can record at at least 24bit/48kHz. The limits are imposed by storage work out how much footage you need and use the calculator here to estimate the amount of storage space you will need: Bit Depth and Sample Rate settings are usually found within the menus of each recorder, consult the manual to find where this is. Always check the settings before recording as the person who used the recorder before you may have had specific requirements that are different to yours. File Formats There are a plethora of file formats in use today. When recording you should aim to record broadcast wave file (.WAV) rather than any other compressed lossy format such as MP3. Once you have compressed your signal it is impossible to recover the lost data. Transfer/Logging Most of our recorders record to SD or CF card, internal memory and hard drive so transfer is as simple as dragging the files from one drive to your edit machine. Because of this it is essential that you give your files meaningful names and keep them organised. One way of doing this is to have a master folder for the project with folders within for each scene and take (e.g. Sc_02_T_003). Then within these folders name each file for the track source (Sc_02_T_003_Character_Lav.WAV or Sc_02_T_003_Boom.WAV). It is good practice to slate each recording at the start (recording someone saying scene and take number etc), so if your logging gets confused you can always listen to the start of each track to find out what you have. You should save a text file in the folder with any notes on the takes, e.g. which take was the best, any noises or issues you noted at the time. Page 13

14 Back up your audio to multiple destinations (e.g a DVD and a hard drive). Don t assume that people will look after your work for you! Health & Safety Sound Levels Using recording equipment at extreme volume levels can seriously damage your ears, not to mention the equipment! It is recommended that you keep monitoring levels low. Using headphones for long periods of time will fatigue the ears considerably. Plan regular breaks in to your shooting schedule to allow your ears to recover. Manual Handling Most audio equipment is fairly light, but you will have to carry it for long periods of time when on location. Boom operators are especially at risk of damage to their back. Again, plan regular breaks in your shooting schedule and put down equipment safely when you can. When you are lifting equipment, please bear in mind the following principles of manual handling proposed by the HSE. THINK BEFORE YOU LIFT; KEEP THE LOAD CLOSE TO YOUR WAIST; ADOPT A STABLE POSITION; ENSURE A GOOD HOLD ON THE LOAD; AT THE START OF THE LIFT, MODERATE FLEXION (SLIGHT BENDING) OF THE BACK, HIPS AND KNEES IS PREFERABLE TO FULLY FLEXING THE BACK (STOOPING) OR THE HIPS AND KNEES (SQUATTING); DON'T FLEX YOUR SPINE ANY FURTHER AS YOU LIFT; AVOID TWISTING THE TRUNK OR LEANING SIDEWAYS, ESPECIALLY WHILE THE BACK IS BENT; KEEP YOU HEAD UP WHEN HANDLING; MOVE SMOOTHLY; DON'T LIFT MORE THAN YOU CAN EASILY MANAGE; PUT DOWN THEN ADJUST. Cable Handling Page 14 Beware of your cables when shooting. Try to run cables away from where people will be walking. Cover runs with a cable trap or gaffer tape.

15 Cables should be coiled neatly and secured with a cable tie if available. (see Bibliography Bartlett, Bruce, Stereo Microphone Techniques Boston, Focal Press, Campbell, Murray, Greated, Clive A., The musician's guide to acoustics Oxford University Press, 2001 Eargle, John, Handbook of recording engineering New York, Springer, Eargle John, The microphone book, Burlington, Elsevier, Katz, Bob Mastering audio: the art and science, Amsterdam; Boston, Elsevier/Focal Press, 2007 Holman, Tomlinson, Sound For Film and Television, Burlington, Elsevier, Holman, Tomlinson, Sound for digital video, Burlington, Elsevier, Yewdall, David, The practical art of motion picture sound, Boston, Focal Press, Page 15

16 Finally Location Audio Induction Pack Please re-read the GROUND RULES (page 1) and abide by them at all times! Copies of this document, links to all manuals mentioned in this document and all other induction materials can be found at: Page 16