La prestigiosa capilla de música de la catedral

Depending on what you're shooting, and depending on your working style as a filmmaker, you have a variety of recording options available. The remainder of this chapter explores a number of different routes you can take, and reasons why you might want to choose one over another. Chapter 8 provides further technical details, and describes how you can put the equipment to use and get the best recording possible.

Just about all digital video cameras ship with an onboard microphone, usually mounted at the front of the camera above the lens (Figure 7-2). These mics often record stereo audio, and they don't require any special setup—as soon as you start recording video, the camera mic records audio onto your tape unless you specify otherwise.

Figure 7-2. An onboard microphone.

7.3.1.1. Pros

Recording sound with the onboard mic is probably the easiest way to capture audio. If you're in a hectic situation, or working by yourself, this is a no fuss, no muss method that generally provides good results.

Using the onboard mic draws less attention to you during filmmaking than some of the more elaborate audio setups described later. You may want to blend into a crowd (for example, if you're shooting on location and don't have a permit, or if you're making a fly-on-the-wall type documentary), and if you're working by yourself with just a small camcorder, you look like an ordinary person.

A recording you make with the onboard mic is recorded directly to your DV tape, making postproduction a much simpler process. Some of the other methods in this section can get more complicated, especially when it comes to maintaining sync.

7.3.1.2. Cons

Because the onboard mic is mounted at the front of the camera in a fixed position, the sound recording is always focused in the same direction as the camera. There are often times in a film where important audio comes from another location, for example, behind the camera or off to the side. In these cases, the sound recording won't be as clear as if you had used one of the methods described later.

Sometimes the sound you want to record will be far from the camera. For example, if the focus of your shot is a couple speaking softly on the other side of the room, you might not get a usable recording because the source of the audio may just be too far from the mic. In this case, you might be better off using an additional microphone.

Also, as mentioned earlier, if you're using an onboard mic, your recording may also inadvertently capture the sound of your camera's motor, which would distract the audience from the audio you're trying to record.

DV cameras enable you to connect an external microphone and record sound directly to your tape (Figure 7-3), bypassing the onboard mic. Different cameras use a variety of inputs, and some cameras require an adapter to connect professional audio equipment. Newer prosumer cameras come equipped with

professional audio inputs (explained in the sidebar "XLR versus mini" in Chapter 8); check your camera's manual for more details.

Figure 7-3. A camera with an external mic attached.

7.3.2.1. Pros

Using an external microphone enables you to choose what type of mic you use. Particular microphone types have different characteristics that are better suited to some situations than others (see "Microphone types" in Chapter 8).

Separating the microphone from the camera enables you to position the microphone to capture the best sound recording possible. Depending on the shot, this may be near the camera or far away.

Because an additional mic is not mounted to the camera in a fixed position, you can angle the mic to record the sound you want, and minimize other sounds that you don't want on your tape. (See the sidebar "The pickup pattern of a mic" in Chapter 8.)

7.3.2.2. Cons

This is more than likely something you can't do by yourself. Using an additional mic to record good sound requires a person's full attention and is really hard to do when you're also running the camera.

You need to buy (or rent) additional equipment. Depending on the type of equipment you buy, you might pay less than $100 for a basic no frills microphone, or several thousand dollars to buy a good quality mic and the other equipment that goes along with it. If you're already investing your time and money to make a professional quality film for theatrical release or a television broadcast, it makes sense to purchase additional audio equipment (sometimes there's no way around spending money on your work), but at the same time, I don't know too many independent filmmakers with extra cash burning a hole in their pockets.

SIDEBAR

Making Your Camera Battery Last

Whether you're using the camera's onboard mic or a separate mic, a camera will sometimes record a 60-cycle hum when plugged into a wall. Running your camera from the batteries rather than plugging in is a good way to avoid this. It also means that you need to keep your batteries charged.

Older, non-lithium camera batteries last longer if you let them completely discharge (meaning

run completely run out) before charging them again. If you recharge a battery before it's completely empty it can develop what's called a memory, and ultimately lose its ability to hold a full charge—you may have noticed the same can happen with the battery on a mobile phone. To prevent this, instead of charging a partially depleted battery, filmmakers often leave a camera on and let the battery run down until it's completely exhausted before charging it. Newer

camcorders ship with lithium batteries that are designed to avoid this type of memory effect, so you don't need to let them run down before you charge them. (Even when I'm using newer equipment, I still generally try to completely discharge my batteries before charging them again

—call me old fashioned.)

Also, if you're not planning on shooting for a few months, it's a good idea to let the batteries wear all the way down, and then recharge them before you store your camera. Batteries last longer if you don't let them go more than about 60 days without completely cycling.

For even greater control over the sound in your film, you can route the audio through a sound mixer (Figure 7-4). A sound mixer is a device that enables you to monitor the audio signals from your microphones and make adjustments before the sound gets recorded by the camera. Using a sound mixer enables you to record with multiple microphones and enables you to adjust each one separately.

Figure 7-4. Two microphones attached to a camera via a sound mixer.

7.3.3.1. Pros

A sound mixer, such as the Shure FP-33, enables you to connect up to three microphones to a camera and separately adjust the sound levels of each one (see the sidebar "The importance of audio levels"). While cameras allow you to adjust the sound level of a microphone's input without using an external mixer, using one enables you to make changes without touching the camera—something your director of photography will no doubt appreciate.

Digital cameras record stereo audio, which is essentially two recordings—one plays back in the left channel and the other plays back in the right channel (mono audio, in contrast, plays a single recording in both channels). Using a Shure FP-33, you can connect three microphones to a camera and control which microphone's signal is recorded to each channel. This technique is explained in more detail in the section

"Using two or more mics, with a mixer" in Chapter 8. A mixer is especially helpful when using different types of microphones together.

7.3.3.2. Cons

Working with an additional piece of equipment complicates your shoot. Using a sound mixer takes practice.

Listening to audio recorded by multiple microphones and making adjustments on the fly takes great concentration and probably won't be the easiest thing you ever do (although the results are worth it if you persevere through the learning curve).

The audio you hear if you listen to the sound mixer may not be the sound the camera is recording. Sound mixers have separate outputs for headphone audio and for the audio that goes to the camera. If there's a problem with the connection between the mixer and the camera, or if one of the settings on the camera has been improperly set, everything may sound great in your headphones but lousy in the final recording. A better solution is to connect your headphones to the camera's headphone output—this enables you to listen to the sound that's being recorded to tape. This may be an inconvenience since you have to stand closer to your DP, but it ensures you know what your tape sounds like. (Higher-end cameras have an audio monitor output that connects to the mixer so you can monitor the actual camera sound, but these cameras are well outside the prosumer price range). You can use headphones with a long cable, but make sure no one trips on it and knocks the camera over, and also make sure the cable doesn't jerk the camera.

Good field mixers aren't cheap: the FP-33 retails for more than $1,250. They're also very heavy, and get even heavier as the day wears on.

SIDEBAR

The Importance of Audio Levels

The sound level, or volume level, of an audio clip describes how loud it is. If an audio clip is recorded at a level that's too low, no one will be able to hear it. If a clip is recorded at a level that's too loud, the audio will distort. (And digital distortion sounds even uglier than the analog kind.)

To ensure good audio, a sound recordist constantly monitors volume levels during a recording and makes adjustments to keep the recording in the proper range. The displays look slightly different on each piece of equipment, but the general idea is the same for all: the loudest portion of the audio level, called the peak, should reach –12 decibels (a unit of sound measurement also written as dB) on digital recording equipment. If a peak level measures slightly more or less than –12 dB, you'll be okay, but you want to get as close to –12 dB as you can.

Many recording devices, including most camcorders, offer an automatic setting that is

sometimes called a limiter. A limiter is designed to constrain a sound level to a limited range as close to the ideal peak level as possible. This sounds like a really good idea, and people often get excited when they learn about it, but it's got a downside. A limiter not only lowers peak levels if they get too hot, meaning too loud, but it also raises the level of the quiet parts of your recording so everything is recorded at a constant level. The result is a recording that doesn't sound natural;

a good audio recording should have parts that are quiet and parts that are loud. (Some low-end consumer camcorders ship with an automatic limiter that you can't turn off—check your camcorder's manual for details.)

If you're in a very loud environment, such as a rock concert, you'll get a more realistic sounding recording if you manually lower the input level of your audio recording. That way, you can get a good recording of even the loudest music. Meanwhile, the more quiet parts, for example a pause between songs, will be recorded at a naturally lower volume instead of being artificially boosted

by the camera. Some cameras, and some microphones, allow you to attenuate the audio and record at a lower level than normal. This is different than using a limiter in that attenuating an audio recording does not raise the volume level of more quiet sounds, it just doesn't record them.

When I was first learning to record audio, my boss told me that if I ever got caught in a riot, I should use the limiter on my tape deck. Other than that, he said, I should use the manual setting.

Not bad advice.

A camera is clearly not the only device capable of recording digital audio for your film. Filmmakers often use separate recorders such as a digital audio tape (DAT) deck (Figure 7-5), a mini-disc recorder, or a portable hard disc recorder to capture sound, and then later, in postproduction, combine the sound and picture (very similar to the way people have historically worked in film).

Figure 7-5. A mic attached to DAT recorder.

7.3.4.1. Pros

The sound recordist and camera operator don't need to be tethered to each other by cables, because the audio is recorded by two separate machines.

What you hear is what you get. A sound recordist listening to the DAT deck or hard disc recorder can listen to the actual recording, and know with confidence what she has on tape.

Many DAT decks and hard disc recorders offer level controls and other adjustments for multiple microphone signals, eliminating the need for an additional sound mixer.

Some recorders can record more than two channels, which might be useful in a shoot with complicated audio, like an orchestra, or five people speaking in a panel discussion.

7.3.4.2. Cons

These units are not cheap. Depending on the features you're looking for, DAT decks and portable hard disc recorders range from $1,250 at the low end of the prosumer scale, up to more than $4,250 and well beyond.

Like the portable sound mixers discussed earlier, they also require specialized knowledge, both to operate in the field, and when you use their recorded audio in postproduction.

When you record to a separate device, sync becomes an issue. There are ways to ensure that sync doesn't become a problem (some are described in the next chapter), but nothing is as simple as using the camera's onboard mic, or plugging a mic directly into the camera.

In the end, recording good audio is just as important to your film as recording good images. Anyone who knows me has heard me say this over and over again (yes, I sound like a broken record), but it can make the difference between a strong film and something people forget as soon as the lights come up. The next chapter explores the details of prosumer audio equipment, including different microphone types and how you can use them to get the best possible recording in a variety of circumstances.

Chapter 8. Digital Audio Production Techniques and Strategies