The DSLR Filmmaker’s Handbook: Real-World Production Techniques, Second Edition (2015)
Chapter 7. Sound on Location
“Sound is never noticed unless it’s bad.” Recording good sound on location is essential for any filmmaker. Working with DSLR cameras is totally different than working with traditional video cameras. They are much more like film cameras. Depending on your particular situation, your best option may be to record audio on a separate device and skip recording audio directly into the camera.
The Role of Sound
Sound has come a long way in terms of both technology and workflow since sound was first added to movies. Yet one thing that has remained constant is the level of difficulty in capturing great audio. It’s a tricky process whether you are shooting on a closed set or on location. There are always various factors that can’t be easily controlled. Getting good audio starts in pre-production, by understanding what you have to work with before you are actually on set.
Sound is critical, but often people don’t notice how important sound is to understanding the surroundings until they process it in isolation. Try this experiment. Shut your eyes. Then sit or stand perfectly still for five minutes and do nothing but listen . . . just listen. Try to critically identify everything you are hearing. And we do mean everything. Are you inside a house? Can you hear people talking, the radio or TV, or a pet? Listen deeper. Can you hear that clock on the shelf, water running in the sink down the hall, traffic or wind from outside, or people breathing? OK, now listen very deeply. Can you hear your computer hard drive or your monitor whine or an air conditioner or furnace fan? Or even the low hum of a refrigerator motor in the next room?
Astonishing, isn’t it? The world is a huge jumble of sound that you take for granted every second of every day. You need to remind yourself that you must record this world of sound to give your film the ring of truth and authenticity. Sound imparts realism, drama, tension, and humor.
Sound is every bit as important as the pictures you see. Still don’t think so? If we say Darth Vader, what do you think of? Your answer will probably include the sound of Vader breathing. It is an iconic part of Star Wars, and we identify with the audio and sound as much as, if not more than, the image of Darth Vader. If we played you just a sound clip of a light saber duel, how many seconds would it take you to identify it as a Jedi battle? Think of the shark in Jaws. We defy you to tell us that you do not hear that “baaadup baadup bump bump bump bump” of the string bass in the orchestra. Hearing the dialogue is essential, but it isn’t sufficient; you must also be able to hear the world around your dialogue. You must inhabit the movie universe that you are trying to create with sound. This requires you to think hard about all the aspects of the world you are trying to capture.
This chapter concentrates on managing and capturing sound on set. Chapter 11, “Audio Crash Course,” talks about working with sound in post.
Hiring a Professional
Just remember that sound is critical to your project, so if at all possible, hire a professional. If you don’t have the means, then make sure to prepare equally hard for capturing sound as you will when picking your camera and lenses. Great sound doesn’t just happen. A lot of hard work goes into capturing great audio.
Extras to Bring Whether You Have a Sound Person or Not
Bring the following:
· Two identical sets of headphones (if the headphones fail, you fail).
· Extra XLR-to-XLR cables.
· Adapters to convert to XLR.
· Various audio jacks, inverters, and converters.
· Extra microphone clips and fasteners.
· Two flashlights (one for you and one to share or if yours gets dropped).
· One Leatherman tool (a multitool is invaluable).
· One multimeter.
· One clipboard with paper and extra pens and two copies of the script.
· Extra batteries. Know all the brands and sizes you will be using and get extras.
· Hairpiece tape, which is excellent for taping down lavaliere microphones on skin or in hair.
· Twenty zip ties, various sizes.
· Twelve rubber bands.
· Twelve safety pins.
· Six spring-loaded clothespins.
· 2" to 12" strips of Velcro.
· Gaffer’s tape.
· Electrical tape.
· Superfine sandpaper.
· WD-40, talc, or baby powder.
· Soldering pen (don’t forget the solder).
· Tiny screwdriver set.
· Two old white T-shirts (for when things get sloppy, dirty, or sweaty).
· A few old blankets for muffling stray sounds, blocking wind, and deadening noises.
In DSLR filmmaking, especially when you have a small budget, every member of your crew has to be capable and actually do multiple jobs. Sound is often shortchanged here, so it is important that you not let it be. In addition, many jobs have similar talents that can easily move from job to job. For instance, a camera assistant can easily be a camera operator and in some cases a director of photography. All of the skills are similar and complementary.
Sound, on the other hand, is more or less its own beast. The skills, knowledge, and even equipment don’t translate to most of the traditional camera and lighting equipment. This is why it is best to hire a dedicated sound professional.
Hiring a sound professional will usually mean that audio will be recorded on an external system. Consequently, you will be getting audio files from the sound person after you have finished shooting. If you are working with a sound person, make sure you discuss how the files will be given to you and how the audio notes will be taken, and ensure that there is a system for file backup. The sound person will also be able to give you recommendations on gear rental and sound requirements for a set, so be sure that the sound person is included in pre-production planning.
Recording Sound with DSLR Cameras
Figure 7-1: Canon 5D Mark III camera
Each DSLR camera is similar but not identical in its audio specifications. Chances are you don’t have an audio background, so making sure you understand your equipment and taking a little extra time to learn or review some basic rules for capturing good audio is recommended.
Let’s start by taking a look at how to set up the basics to run audio from a camera. No cameras are identical, but there will be some similarities in their audio setups, so we will use the Canon 5D Mark III (Figure 7-1) as our example model.
First, just look at the specifications on your camera. This will help you get acquainted with some of the basic terminology and things that can be done with your camera in terms of audio.
Figure 7-2: Close-up of 5D Mark III internal mic
The 5D’s built-in microphone is an electret condenser microphone (Figure 7-2). These microphones used to have the stereotype of low-quality microphones, but now the best models are regularly accepted as professional-grade microphones. The major challenge with audio on DSLR cameras is the audio input and sampling rate.
The Canon 5D Mark III records 16-bit 44.1 kHz linear PCM audio in the camera. You have the ability to control the sound recording as Auto, Manual, or Disable.
The Auto setting (Figure 7-3) is a form of automatic gain control (AGC). This auto gain control will amplify many ambient noises or sounds, such as wind, car engines, and so on. This amplification of peripheral noise will distract from the dialogue you are trying to record cleanly. In a movie, it is most important for the dialogue to take auditory precedence because most of the other sound can be added or tweaked in the mix. For filmmaking or narrative pieces, any use of auto gain will certainly identify your project as low budget and not professional. AGC works great as a reference audio track to be used during post, but it should not be used for the actual audio capture to be used in a final mix. If you are ever in an emergency situation and must use the on-camera audio, turn off the automatic gain control and manually control as much as possible.
Figure 7-3: Auto, Manual, and Disable audio options
The manual settings are a recently added function of the camera; they allow the operator to manually control the audio levels. When you select Manual in the sound recording menu, you get a Rec. Level adjustment bar to manually control your audio levels.
As with any audio recording, you want to set your audio levels to peak right between –12 dB and 0 dB. If your audio levels exceed 0 dB, then your audio will be clipped, or distorted.
Image Stabilization Systems Make Noise
If you are relying on your built-in camera microphone, be aware when you use image stabilization (IS) lenses. An IS lens has a built-in gyroscope. The Canon IS system uses a microcomputer that controls sensors, actuators, and two micro gyros to eliminate vibration—and the IS system is always active in Video mode. The IS lens produces a very faint scratchy noise that is almost unnoticeable to the human ear, but it all but takes over the audio track on the camera. If you are using an IS lens, it is imperative that you use an external microphone of some sort to give yourself a good clean reference audio track in the camera.
Audio levels need to be set or normalized so that all sounds fall within a specified range and can be accurately recorded. As you set audio levels, you will need to be aware of where the upper and lower limits of the audio are set, and all sounds should fall between these limits. Audio will need to be normalized or have the entire signal adjusted so that it fits into the levels or norm. Essentially, you are moving the peaks and valleys, the highs and lows, to a range where they all can fit and be recorded. It is the audio equivalent of making sure that the camera is set to accurately record the whitest and blackest areas of your image.
Other DSLR cameras will operate similarly but with slightly different menus. For example, the Nikon D3S has a built-in monaural microphone, and you can attach a stereo microphone via the hot-shoe mount. You have the ability to set your microphone to High, Medium, Low, or Auto sensitivity or turn it off through the camera menu.
With any DSLR camera, it is important to read the technical specifications for the type of microphone, the input of the camera, and the recording specifications. In general, however, no DSLR camera has audio quality that is good enough to be used as the primary audio recording method for a high-quality project.
Using an External Recording Device
In reality, if you are going to make a movie or other dramatic project, you must use an external recording device and record in a double system. “Recording in a double system” means capturing audio with the camera as well as an external recording device. Think of your project just like a film shoot: record the image in the camera, get your high-quality sound from a separate device, and sync it in post.
Practically speaking, it is best to capture audio externally. It is easier and more efficient to get better audio using a dual recording system where the camera records the image and audio for matching purposes and a separate audio system is used to record audio. These devices allow for a direct digital recording from a microphone and provide a much higher-quality recording.
Bit Depth and Sampling
DSLR cameras have limited audio bit depth and usually top out around 16 bit. External recorders record higher at 20–24 bit depth. This increased range greatly enhances the final audio. External audio recorders also record at high sample rates. The sample rate is the number of times an analog signal is measured (sampled) per second to represent that sound. The more samples taken per second, the more accurate the sound can be. The unit of sample rate is samples per second. This is often expressed in kHz. For example, the current sample rate for CD-quality audio is 44,100 samples per second, or 44.1 kHz. Simply stated: the higher the sample rate, the better.
External audio recorders will provide a higher bit depth and often better sampling.
Figure 7-4: Tascam DR-40 external recorder
It can seem intimidating to have a separate system for recording audio, but even if you are doing audio yourself, it is actually easier to have a dedicated audio setup that functions separately from your camera. If you keep them separate, you have the option of getting several more channels for audio, the ability to record performers with multiple microphones, greater ease with post-production mixing because of multiple channels, easier voice-over or dubbing capabilities, freedom from having extra microphones or cords attached to your camera, and the ability to hand over the role of audio to another person (ideally a professional or at worst an ambitious assistant).
Audio for DSLR projects is usually captured externally by using one of a variety of digital audio recorders. These devices have many different features, but the key components that you need to look for are the ability to record high-quality audio with multiple inputs, multiple-channel ability, storage capacity, and ease of use including the ability to label takes.
When capturing audio externally, you may also need to add an audio mixer to the gear list if you have multiple tracks that need to be recorded concurrently or live.
You have a variety of options for external audio recorders. One of the most popular recorders available is the Tascam DR-40 or the Zoom H6 recorder (see Figure 7-4).
The Zoom H6 records on standard SDHC cards. If you get a 32 GB card, at the target rate of 48 kHz 24-bit you can record for about 151/2 hours.
If you want to go with a more professional-style audio recording setup, a Sound Device 744T digital audio recorder is a good option (Figure 7-5). The 744T is a powerful four-track file-based digital audio recorder. It records to and plays back audio from its internal hard drive, CompactFlash cards, or external FireWire drives. It writes and reads uncompressed PCM audio at 16 or 24 bits with sample rates between 32 kHz and 192 kHz.
Figure 7-5: 744T digital mixer/recorder
If you are not an experienced field audio professional, this system has a low learning curve, and you can set it up and be running in no time. If you add a Sound Device 422 outboard field mixer, you have a truly portable audio station. The removable, rechargeable battery is a standard Sony-compatible Li-ion camcorder cell.
The 744T interconnects with Windows and Mac OS computers for convenient data transfer and backup. Its recording media (hard drive, CompactFlash cards, and external FireWire drives) are reliable, industry-standard, and easily obtainable storage.
If you have time during the workday, you can download your audio for backup, or if your schedule doesn’t allow, there is more than enough storage to wait until the end of the day to dump your audio files and back them up.
Capturing Reference Audio
Even if you are recording to an external audio system, it is helpful to use the audio captured with the camera for reference during post. None of the onboard audio will be used in the final project, but reference audio can save time and answer any syncing questions in post. Even if you are just capturing reference audio, it makes sense to try to capture good reference audio, and a little extra work and effort will save you time on the backend.
The first step to getting better in-camera audio is to upgrade the onboard microphone wherever possible. If you are in a quiet, small location or in a location where a large microphone might draw too much attention, then you may be able to get away with the camera’s built-in microphone. With that said, you are risking headaches and extra work in post relying on the built-in microphone even for reference. Adding an accessory shotgun mic for getting the best possible reference audio into the camera will be useful for capturing reference audio.
You can buy a variety of hot shoe–mounted shotgun microphones (Figure 7-6) that you can plug directly into your camera and get a decent reference audio track to use in post. This is essentially boosting what you would get with the built-in camera microphone and making sure the signal strength is good and you don’t have things like the noise from an IS lens overpowering your reference audio track.
Figure 7-6: Hot shoe mount
Using these sorts of microphones is a way to create a better audio reference track in the camera that you will use to help sync your audio in post. The audio will still be controlled either by the camera’s AGC or by the manual control if your particular camera model allows manual audio adjustments.
If you choose to use an onboard microphone for ambient audio recording outdoors, use an additional windscreen. Any wind will ruin the audio, so a cheap windscreen can save you a ton of headaches in post. Both Rycote and RedHead offer windscreens that will cut out any unwanted wind noise. The H4n also has phantom power if you need to power microphones without batteries or another external power supply. It also has a headphone jack for monitoring, which is a clear advantage because you cannot do this with most DSLR cameras.
Deciding how you are going to record audio is just the beginning of the process. After determining your primary audio recording system and reference audio setup, you will need to plan the audio setup for the shoot. Here is where an audio professional will prove most helpful in deciding what additional gear is required and how to set up a coherent system to record quality audio throughout the shoot. Remember, moviemakers are responsible for planning all the audio, and you must understand that audio gear as much as possible in order to communicate your wants and needs with the actors and audio technicians. The next step to recording audio on set is planning the microphones, or ears, of the shoot.
Using an XLR Audio Adapter
Two major drawbacks in recording audio on your DSLR camera are the inability to see your audio levels and the fact that there is no audio-monitoring jack so you can listen and adjust your audio while you are recording. An XLR audio adapter can fix one or both of these problems. Any XLR adapter will have a headphone jack that allows you to plug in headphones and monitor the audio live. This allows for quick, small adjustments to the audio during the scene to make sure the audio levels are strong and consistent throughout the scene.
We don’t normally recommend XLR adapters because external audio recording is superior. However, if you must record audio directly into your camera, an XLR adapter will be very helpful.
Some XLR audio adapters also have audio meters on the front that visually show you the audio signal strength. This is just another way you can quickly look and make sure your audio signal is strong without being too strong to clip the audio signal.
Another reason to use XLR audio adapters is the ability to use an XLR audio cable as opposed to a smaller, mini audio plug. The XLR cable is a professional audio cable designed to carry a much stronger and better audio signal than what is possible to transmit through a standard mini plug. With that said, we don’t consider the benefits of the XLR cables to be great enough to make them a valid choice.
XLR cables are balanced, which means they have three wires inside the cable itself. One carries the signal, another carries a phase-inverted signal, and the third is a shield/ground wire. When the signal gets to the recorder, any noise that is present on either of the two audio signal wires gets automatically canceled out or rejected by two of the three wires. So, think of it more as one XLR cable carrying one channel of sound on three wires and being auto-noise-rejecting. A normal mini-plug cable carries two channels of sound on three wires. This makes mini plugs much more susceptible to noise because nothing gets canceled internally in the cable itself. This is why XLR cables are so much better than standard stereo mini-plug types or even single-channel 1/8-inch (3.5 mm) audio cables.
There are a few XLR adapters on the market, but the two most prominent are the Beachtek DXA-SLR PRO (Figure 7-7, www.beachtek.com) and the juicedLINK Riggy-Assist (Figure 7-8, www.juicedlink.com).
Figure 7-7: Beachtek DXA-SLR PRO for DSLR cameras
Figure 7-8: juicedLINK Riggy-Assist RA222 phantom power unit
These adapters have XLR inputs, phantom power, and gain control. That is great, but you still must come out of the adapter and plug directly into the camera’s 3.5 mm input, thus leaving you with the same 16-bit 44.1 kHz audio you started with. Unless there is some special need for your project, it would be better to just use an external device and not have the extra expense and extra piece of equipment attached to the camera.
Always make sure to use headphones to monitor the sound of the microphone before and during the shoot. The pickup patterns vary, and monitoring the microphone will ensure that you are getting the sound you want. Not monitoring can mean that when you get back to the edit suite, you discover that the entire day of shooting is worthless because your actors sound like they are speaking to you from a cave in the Antarctic.
Get the full ear cup style. They provide a great seal for maximum isolation. Cutting down on outside noise really helps you hear what you are getting.
Do not use the in-ear bud style for monitoring or recording audio. One bad feedback squeal and you can permanently damage your hearing.
Use a Y-Cable Splitter for the Headphones
Use a Y-cable to split the headphone jack. You can take one audio input to plug in your headphones and use the other input to plug directly into your DSLR camera’s 3.5 mm input jack. This will be a huge assistance in helping to sync the audio in post. This eliminates any sound differences between the reference audio and the master audio that can from time to time make it difficult to sync.
Also, just because you are bringing your 24-bit 48 kHz audio from your external recorder into the camera, don’t think that you can use the audio on the camera. The audio quality is being dropped back down to the camera’s audio limitations (16-bit 44.1 kHz audio). You should use the audio recorded in the camera only as reference audio for post.
A side benefit of using a split audio feed is if you play back your takes directly from the camera, you will have your actual audio (reference only) synced with the clip while you play back your dailies. This gives you a pretty good idea of what you have and whether you need to reshoot or are good to move on.
Just note that it is important to double-check your levels if you do use a splitter because every time you split a signal you lose 3 dB of gain. This is just the physics of splitting an audio signal in half and can’t be fixed. Just be aware and make sure you are still getting good levels during the audio capture.
Microphones and Key Accessories
All microphones either are designed to pick up audio in varying patterns or are most sensitive to certain sounds. Thus, some microphones are better than others for different situations. If you are unfamiliar with microphones, take a look at the most common ones.
Types of Microphones
Microphones are designed to fit various scenarios, so deciding what is required of your shoot is important. In general, microphones that will be used on set fall into two broad categories:
1. Condenser Condenser microphones allow for a high-quality sound recording. They require power to work. The power, known as phantom power, can come from a battery in the microphone or can be sent down the microphone cable from a mixer or recorder that has phantom-power capabilities. These microphones tend to be more sensitive.
2. Dynamic Dynamic microphones are well suited to fieldwork and do not require extra power to function. They can handle loud sounds well, and they are very sturdy. Years ago, we had an actor drop a Shure SM 57 microphone out of a third-story window to the asphalt driveway below. We still have that microphone, and it works perfectly.
If you categorize by type, size, construction, and cost, there are hundreds of different kinds of mics. They have different pickup patterns, sensitivity, and accuracy. There is no one correct microphone to use for any given situation. However, you want to try to use the best tool for the job at hand.
These are a few specialty microphone types you might need for particular circumstances:
1. PZM Microphone PZM stands for “pressure zone microphone”; it is also referred to as a boundary mic. These types of microphones actually attach to tables, Plexiglas plates, the floor, or other flat surfaces, and they capture the sounds that reflect off the surfaces to which they are attached. They are great for micing big space sounds like an audience laughing or clapping. If you use them on a table, be aware that every little finger tap will be heard, so make sure this is the right microphone for your scene if you choose to use it.
2. Lavaliere Microphone A lavaliere (see Figure 7-9) ranges in physical size from small to tiny and can be attached to lapels, collars, and hats. Or, it can be hidden inside a shirt or hair. In fact, they can be stuck almost anywhere. They are extremely versatile but are not the easiest microphone to use. You must take great care when placing these little gems, because they can pick up everything. Your sound enemies become clothing noise, breathing, mouth and lip noises, heartbeats, and so on. Put them too close, and they will sound boomy. Put them too far away, and the voices will be overwhelmed by background noise. However, when you find the sweet spot, they can deliver stunningly good sound. The most common type of wireless microphone is lavaliere microphones.
Figure 7-9: Shure FP1/FP5 Wireless lavaliere
3. Shotgun Microphone Shotgun microphones get their name because the microphone element is placed in a tube that looks like a shotgun barrel. They are most commonly attached to the end of a pole so they can easily be directed at an actor or object that needs to be recorded.
A boom microphone is simply a microphone at the end of a long pole (Figure 7-10). The designed use of a boom pole is to place the microphone directly above or directly below an actor’s face just outside the camera frame. This allows the microphone to get as close to the source of audio as possible without being seen in the frame. A boom pole is usually operated by a sound person, but if there is no movement by the actors in a given scene, sometimes the boom pole is mounted to a C-stand, so the audio person doesn’t have to hold the boom pole for every shot.
Figure 7-10: Boom microphone on the set of The Shamus
Boom poles are lightweight and usually made of carbon or aluminum. These telescoping rods can be either handheld or attached to a stand to capture your audio. Some models have the microphone cable inside the tube, which not only protects the wiring but also is much easier to carry around. They are more expensive, but this is where you need to be the judge of whether it is worth the extra money.
Technique is very important when using a boom, so whoever is going to be holding it needs to practice using it before you start shooting. Start by placing the microphone just out of frame. Work above and a few inches in front of the head, with the microphone pointed toward the actor’s mouth and in the general direction of the floor. You can also work from below and point up toward the ceiling if that is what the shot dictates. Pointing up or down eliminates picking up a bunch of background sound because the floor and ceiling don’t make noise. Pointing the microphone in other directions can capture sounds behind or around your actor.
Figure 7-11: A vampire clip to help reduce the rubbing of clothes against the microphone
Any time you place a wireless lavaliere microphone on an actor, you are open for unwanted sounds to appear. Any sort of rubbing of clothes against the microphone or just a little bump of the microphone by an actor’s hand when adjusting his shirt could potentially render a take unusable. Get yourself a cheap insurance device commonly called a vampire clip (Figure 7-11). This can be anything from a shielded enclosure that you place your lavaliere microphone inside (like a cage that keeps clothing and unwanted objects from bumping or rubbing against it) to a furry tape that will keep the microphone attached to the actor but not allow for any wind to interfere with the audio being recorded.
Another tool is a suspension-style clip; these are usually made with elastic bands that hold the microphone suspended in a cage or fork. When attached to the pole, the clip isolates the microphone from the noise transmitted through the pole.
After looking at the various microphone types, it becomes apparent that where you place the microphone and the type of microphone used are critical to getting great audio. In general, the closer you place your microphone to what you want to capture, the stronger and better the audio signal you will get. Conversely, get too close, and you might get the microphone in the shot or have that audio signal be too strong so that the audio peaks or is crushed when being recorded. Here are a few tips to remember:
· Choose your microphone’s audio pattern for what you want to record. If you want to get room tone, choose an omnidirectional microphone to best represent the location’s audio characteristics, and if you want to get a line of dialogue, use a good shotgun mic on a boom as close as you can directly above your talent.
· Get the microphone close to your subject. If you are using a wireless microphone, place the microphone as close as you can to the actor’s mouth or throat. The farther away from their voice box, the worse your audio will sound.
· When do you actually place the microphones? In general, any microphones being used on your actors are placed as soon as the actors are on set, in costume, and ready to shoot. Boom microphones should be set up and ready as soon as the sound person is on set. Any placement of microphones within the set needs to be coordinated with the grips and art department. In general, the microphones are placed in the set or in props after the set is decorated and lit. This will depend on what sort of set you are working on and several other factors, but the sound should be ready to be placed as soon as possible so as not to slow down the shoot.
This is also a great time to mention something called proximity effect. If you do not know what this is, try this experiment. Move your mouth closer and closer to the mic while talking. Hear how the bass frequencies get exaggerated? That is proximity effect. Don’t let the talent get too close to the mic, or everyone will sound like James Earl Jones.
Microphone Pickup Patterns
Pickup pattern refers to the physical dimensions of what, where, and how well the microphone hears depending on where it is pointed. Think of a regular lightbulb. Put it on a simple straight stand with no shade attached and turn it on. A microphone will hear everywhere the lamp shines. The pickup pattern of a microphone changes how much and where the microphone hears.
Microphones are designed to pick up sound in very specific ways and are specialized as to in what areas they pick up sound the best. You need to look at an individual microphone as possessing a specific sound field, or area of capture. Knowing and planning for this invisible sound field where the microphone will pick up sound allows you to map your set.
You can choose microphone placement according to where the sounds you want recorded are coming from and the placement of your actors on your set. By knowing your microphone’s polar pattern, you can help cut down on sounds you don’t want recorded that are present at your location and at the same time plan specific microphones to pick up desirable dialogue or background sounds you want to capture.
There are three basic sensitivity patterns.
Omnidirectional, Cardioid, and Hypercardioid Microphone Polar Patterns
An omnidirectional microphone polar pattern is omni, or all around (Figure 7-12). This is best used when trying to capture sounds from a large area around you. On the flip side, this is generally not a microphone for getting dialogue.
Cardioid, from the Greek for heart, has a pickup pattern that looks like . . . wait for it . . . a heart (Figure 7-13). With excellent sensitivity to the front and good pickup to the side, one of the strengths of this pattern is its ability to reject sound from the backside of the mic. It is a much more unidirectional, or one-direction, microphone so it works great in limiting the amount of room ambience the mic hears.
Pickup patterns are easy to visualize. Think of a 10-inch-tall mushroom. Imagine stuffing the microphone up through the middle of the stem until the head of the microphone is buried at the base of the cap. The mushroom is the pickup pattern for most cardioid microphones.
Hypercardioid is a tighter pickup pattern version of the cardioid but not as extreme as a shotgun microphone (Figure 7-14). These are excellent voice or speech microphones; be aware that the pattern is tighter so you do not want the talent to be far off to either side of the mic.
Shotgun Microphone Polar Pattern
The pickup pattern on these tends to be like a flashlight beam (Figure 7-15). These microphones excel at capturing the noise in the flashlight beam and not hearing sounds to the sides of the tube very well (this is known as off-axis noise rejection). These are generally great for dialogue and interviews.
Figure 7-12: Omnidirectional pattern
Figure 7-13: Cardioid pattern
Figure 7-14: Hypercardioid pattern
Figure 7-15: Shotgun pattern
Feel free to be creative with microphones. How you use microphones is almost more important than what you use. Using two or more microphones at the same time to capture performances gives you tremendous flexibility. A close microphone will give you an intimate sound, and a farther-away microphone will capture a bigger room sound. Microphones are best used if you use several and layer them, thinking about where each sound can best be recorded and designing the type and placement of a microphone for that sound. For example, several different microphones should ideally be used for the same scene, with each microphone set to pick up different voices or sounds.
Mixing different levels of those will give you great choices. You can hide microphones. Think of all the spots the camera cannot see. You can sneak microphones behind props or actors, on C-stands just off-camera, in clothing or hair, in plants, hanging from the ceiling, or on almost anything that is out of the sight lines. The flexibility of a microphone on a boom is limitless. The good news is that once you get the microphone off the camera, you have already taken the biggest step in improving the audio quality of your project.
Also consider these accessories to improve sound quality:
1. Zeppelins or Windscreens These are cages or fuzzy socks designed to protect the microphone and help filter out wind and background noise. Unless you are on a very quiet soundstage, you will want to use them, depending on conditions and ambient noise.
2. Sound-Deadening Blankets Think of the kind of blankets you get from a moving company. Having a bunch of these (10–15) on hand or in a trunk can be lifesaving in difficult situations. You can drape them or tape them to wherever you need to deaden sound or knock down wind. They also work great as sun shields. You can fold and stack them to rest cameras or other gear on. You can clip them to C-stands and build makeshift changing rooms or dark rooms. They can protect gear from rain, snow, dust, and hail. They work for padding when packing up gear.
Planning, Setting Up, and Recording a Shoot
This sound design time is essential to ending up with a good overall sound signature for your film. The first thing you have to do is sit down and decide how you want your film to sound. Will there be voice-over or narration? Will there be sound effects? Will you have to go into the field and capture or create them? Will there be a music track? Will there be music in the film?
Whatever you decide for your sound palette, write it all down. Find the spot in the script where you need a doorbell and write it in. Go to where in the script you need a phone to ring and write it in. Then, go to the last tab in your notebook and write “Sound Effects.” On that last page, start a list. Describe what you need. Write where in the script it belongs and add other needed sound criteria. Here are a couple of examples:
1. “BELL CHIME, DING-DONG STYLE OF DOOR BELL, 3 DING DONGS,” page 6, scene 1; doorbell sounds from far away down a hall
2. “OLD-FASHIONED BELL RING, PHONE 5 RINGS,” page 8, scene 2; phone is in the room and on the wall
Do not forget to pay attention to sound placement; sound placement dictates microphone placement. If the phone is on the right side of the screen, pan the sound a little to the right when mixing. Don’t overdo this and pan the sound all the way to the right unless you are trying for a weird effect. In the real world, both ears hear the sound; it is just that one ear hears it first and a little louder. Our brains are extremely good at hearing and interpreting those subtle differences. Using this trick when placing your sounds will add great realism to your sound track.
Planning for Dialogue
There are a couple of things to keep in mind when capturing dialogue. The voice of an average adult male speaking usually falls in the fundamental (think notes on a piano) frequency range of 80 Hz to 150 Hz, with 80 Hz representing the lowest frequency of a well-trained bass singer. The average fundamental frequency range of females speaking is from 155 Hz to 265 Hz, although sopranos can sing as high as 1170 Hz.
Knowing where in the frequency range voices fall is critical when recording and mixing. For instance, a lot of very problematical noise comes from frequencies below 60 Hz to 80 Hz, such as heating, ventilating, and air conditioning (HVAC), wind rumble, and trucks, to name just a few. Many microphones come with a bass roll-off or rumble filter built in. When switched on, these filters cut down the microphone’s ability to hear those lowest frequencies. Depending on the microphone, these cutoff switches might be at 40 Hz, 80 Hz, 100 Hz, or higher. (Some microphones will give you multiple frequency choices.)
A good rule is to start with the lowest cutoff and see whether that eliminates the problem. The human voice does not go much below 80 Hz, so if the microphone is set to roll off at 60 or 80, you are not going to be missing many of the fundamental frequencies of the voice, but you might be eliminating a lot of low hum, buzz, or rumble. Power is another source of 50/60 Hz hum that can easily be picked up through improperly grounded wires and audio setups.
Two Sample Setups
Go to where you will be shooting. If possible, go at the same time of the day you will be shooting to better match the filming conditions.
We will be using the following scenarios as examples:
· A kitchen with three people, two at a table and one cooking
· A car ride on the freeway with two people, both in the front seat
Go to the kitchen or the set where you will be building a kitchen, sit down, shut your eyes, and, just like in our earlier example, listen carefully. What do you hear? What can you hear that could be a problem? HVAC? Refrigerator compressor? Fluorescent light fixture buzz? Outside traffic? Might there be people walking around upstairs or downstairs? Are there many reflective surfaces that can create funny echoes? Hard floors or carpet? Try to think of everything that can interfere with the quiet recording of sound, and try to eliminate them. Can you unplug the refrigerator, shut off the HVAC, turn off the buzzing lights, or hang blankets to deaden echo? If you have hard floors, consider having the talent and the crew take off their shoes and walk in socks.
For this scenario, if you are shooting mostly close-ups, you could be recording two tracks of audio. You would use one boom microphone to cover the table dialogue and, at the same time, one omni microphone in the air to capture the ambient action. You would try to shoot the entire dialogue that happens between the actors at the table first. Set the boom between, above, and slightly in front of the actors. Then, all you have to do is simply rotate the microphone back and forth as the actors exchange lines. Only after you have all the interplay between the two actors at the table should you move the boom microphone and film the lines of the actor who is cooking. Remember to match the actor’s situation with the voice. Visual close-ups sound right if you are using close micing; is the cooking actor in the background and farther away? Consider using the omni room mic to capture his dialogue. He will look farther away, so you will want it to sound like he is a bit farther from the camera. Is there something cooking on the stove or grill? Consider recording separate tracks of whatever extra sounds the scene calls for: sizzling steak, boiling water, or a toaster popping up at a later time. This keeps your dialogue tracks as quiet as possible.
You should always have your script in front of you as you are working to help cue when to turn the microphones as the actors speak.
By the way, this blueprint is just a suggestion. There are as many different ways to record a scene as there are recording engineers. For example, let’s say you know you are going to be using mostly wide shots that show all three actors and a lot of kitchen. In that case, you would use three lavalieres for the actors and one omnidirectional microphone hidden behind the ceiling light for more ambient-sounding dialogue. Remember, if you are going to go this route, you would need to have equipment capable of recording four separate audio tracks at the same time.
OK, let’s look at the car scenario. Automobile scenes are very hard to capture. Cars are really noisy, and it is all the worst kind of noise: low road rumble, traffic, engine sounds, wind . . . yuck. If you have a great budget, get a flat car trailer and shoot the scene while towing the car. That eliminates a ton of problems. If you get a big enough trailer, your camera crew can also be riding the trailer and shooting the scene.
Remember: safety, safety, safety! You don’t want anybody getting hurt.
Pull off the door panels and stuff them full of soundproofing. Hang towels from the windows. Get the car tuned and check the muffler. Car ignitions can wreak havoc with sound and electronics, so check that ahead of time. We like to suspend two lavalieres from the sun visors just out of frame. Hanging them from their wires helps isolate them from car noise.
There are other good options:
· Does the car have to be moving? As we mentioned, if there’s no movement, there’s way less noise.
· Can you green-screen the ride?
· Can the dialogue happen before or after the car moves?
Recording a Shoot
The main thing to remember is that you always want to record sound in the cleanest, quietest, and most natural-sounding way possible. Although there are amazing tools available to fix sound problems, you really don’t want to spend your life trying to “fix it in the mix.”
· The sounds should be “dry” and without any kind of reverb or effect. If you need to add something to the sound to make it a better fit for your movie, do so while editing in post-production.
· In almost every case, the more tracks you can record, the better. Different microphones and different sound sources give you greater flexibility when editing.
· If you can, record trial dialogue at the location you will be using so you can hear what it is going to sound like. Make adjustments, record it again, and don’t be afraid to experiment.
Managing Sound on Set
Record keeping is a big key to success! Plan the system for audio notes, and make sure that each scene number, take number, actors involved, tracks, and audio notes on the quality of the takes are written down. It is often better to rely on handwriting the notes and then transferring them to a digital format because laptops or other devices can get unwieldy on set. The sound notes and files must be cross-referenced with the script and scene numbers, and takes must be easily identifiable with each sound take. Discuss what scenes are planned for the day with the key crew members, especially the script supervisor. At the beginning of each scene, double-check the numbering to make sure everything is matched.
Figure 7-16: A digital slate
In modern filmmaking, when directors have a good take, they look to the camera operator to make sure that there were no technical issues and then turn to the sound operator to make sure there were no issues with the sound. This is the time to bring up any audio problems that you hear and make adjustments. Take notes about what adjustments were made or problems that will have to be dealt with in post. After the shoot, keep all backups of audio until all the post-production is completed.
Slating Each Take
We talked in Chapter 1, “Fundamentals of DSLR Filmmaking,” about the need to slate each take (whether with a clapboard like the one in Figure 7-16 or simply by clapping your hands) and then use the audio peaks to sync the camera/reference audio with the external sound. In Chapter 12, “Color Correction and Grading,” we explain how to use the software plug-in PluralEyes to do this syncing.
Recording Room Tone
Whenever you are filming, take three to five minutes to capture the ambient sound of the area you are filming. This audio clip should have no speech or defining sounds. This is known as room tone. If you want professional sound, get room tone. This trick will save you hours in editing and tons of frustration. Let’s say you have to overdub voices because one of the actors had a head cold and his dialogue sounded like he was stuffed up. You can record those voices later in any quiet environment, put a track of the original site room tone underneath it, and ta-da! It sounds like the actors recorded that dialogue on the original site. Having a few minutes of room tone will allow you to do all kinds of sneaky editing tricks that will help make your sound real and seamless and can sometimes save you from disaster. Don’t forget; if you go to a different spot to shoot the next scene, you’ll need new room tone.
Setting Sound Levels
With your camera and light, too much or not enough can ruin the picture; sound is the same. Too high a level, and the sound will be distorted. Too low a level, and when you have to turn it way up to hear it, you will also be turning up the noise you captured, and all you will hear is hiss.
Look carefully at the four examples in Figure 7-17, Figure 7-18, Figure 7-19, and Figure 7-20. These are exactly the same sound source recorded at different levels. See how the graphic shows dips and spikes? Think soft and loud. The smaller the dips, the softer the sound. See that jump right at the end? This is called an audio peak. It is the loudest part of this clip.
Take notice of the example marked “too high a level” (Figure 7-20). See how the peaks of the sound seem to be chopped off at the top and the bottom of the graphic? This is an example of clipping, which is very undesirable. You are losing a critical part of the sound when this occurs. Think of this just like filming with way too much light. The picture is blown out, and a huge amount of detail is lost.
Conversely, when you look at the example marked “too low a level” (Figure 7-17), you can see that while you are capturing the sound, there is definitely room to increase the level and thereby increase the amount of detail you are capturing. Again, think of filming in no or low light. You are seeing the picture, but the detail is hard to make out because it is so dark.
Figure 7-17: Sound wave file with too low a level: low audio signal
Figure 7-18: Sound wave file with a good audio signal
Figure 7-19: Sound wave file with a perfect audio signal
The other two examples show what it should look like when you are capturing good levels. If you are an amateur or working on your own, you should try to match the graphic titled “good audio signal” (Figure 7-18). If you are skilled or have someone who can monitor the levels as you go, you should try to match more closely to the graphic titled “perfect audio signal” (Figure 7-19). Remember, you do not want to clip the levels. You should always try to get your audio to peak between –12 and –6 dB to make sure you have a strong signal and don’t lose data to clipping.
Figure 7-20: Sound wave file with too high a level: clipped audio signal
Avoiding Clipped Audio
If your audio signal is too strong for your capture device, then the high end of the audio you are capturing will simply peak out and essentially be clipped. It is important to monitor your audio to adjust for this and make sure to adjust your signal strength so that your signal is being captured between –12 dB and 0 dB so as not to be clipped.
Conversely, if you don’t raise the audio input so the loudest levels are at least –12 dB, your audio might be too faint to hear and leave you with unusable audio. Using this manual audio setting is great to help get clear audio that has the normal high and low range of natural speech that you would hear naturally in a scene—unlike an auto gain where the lows are automatically raised to the high tones and the high tones are lowered toward the low tones. This results in ambient noise bleeding into your dialogue and the range of your audio being compressed.
You can also set your camera to disable the audio recording. This will save you a little in terms of the size of your files but not enough to recommend this option. Unless you are shooting a silent film, it is critical to have a reference audio track to work from.
If you are bemoaning the lack of features on your camera, there are unauthorized firmware extensions that you can look into. Obviously, when using an unauthorized firmware extension, you are taking on risks that will not be covered by your manufacturer. However, even if you don’t use these hacks, you should be aware of their existence and decide on your comfort level in case someone on set brings up the idea of using one.
One of the most popular firmware extensions is Magic Lantern. Magic Lantern runs on an open framework and is designed to run alongside any firmware that is already in use. This extension adds various features to supported cameras. Some features are on-screen audio meters, zebra stripes, crop marks, and various audio and focus features.
Ultimately, you will need to make your own decisions on using unofficial firmware extensions. To learn more about these firmware extensions, you will need to do some searching. To get started, you can check out the Magic Lantern details here: