The concept of production dialog is relatively simple. The actual execution of it can get fairly hairy.
The concept: put a microphone about one to two feet away from the mouth of anyone who talks. Don't record any sounds other than them talking.
The execution: oof. It's really really hard to do.
Sound on set.
Now, once upon a time we had a sound cart which looked like this:
We're not going back to that kind of system until we have enough money that we can afford a half-dozen wireless mics and someone who's really good and wiring hidden mics without a lot of clothing noise. That day is not today.
A while back I wrote this page on field recording. It's a tad archaic as it assumes we're recording sound direct-to-camera (which we so aren't doing).
I also wrote a post on why I don't dig shotgun mics.
Right now what we use is the Oktava microphone (with a hypercardioid capsule) going hard-wired into a Sound Devices 702 (non-timecode) recorder. That recorder uses CF cards to record audio onto.
If you've used the 702 before you've enjoyed how simple and straightforward it is. Press the big "record" button to roll record, and the big "stop" button to cut. The best feature about the 702 has to be the awesome limiters it has on the mic preamps. If someone does a take a whole lot louder than you expect, you just can't go into digital overload (once you've heard digital overload you'll realize why you'd almost have any other sound than that.)
The way we set up sound is to record broadcast .wav files (poly). Those are at a sampling rate of 48kHz and a bit-depth of 24 bits.
We record using sequential "take" numbers. That is, you don't go and set a scene or a reel number. If we're shooting a project with a job number of "0801" our first take will have a file name which looks something like this:
The next take will be
and so on. Normally several hundred takes will be recorded throughout the making of a feature.
How we "roll sound."
As we typically do not have an AD on our feature, the director/camera person will say "Roll Sound".
The person with the sound recorder will press the record button and then say the take number aloud. For example:
"Rolling. Take 238."
Then the camera person will roll camera and repeat the take number
"Take 238. Mark it."
And the person with the slate will drop the slate.
What happens at the end of the day?
The CF card in the recorder contains a number of folders. The most important of those folders has all the takes of the production sound on them. As we tend to use 32GB CF cards on our features, there's no reason to delete any of the sound takes from the CF card until we begin production of our next feature.
The CF card is typically put on a computer with a CF card reader and the files are transferred to the "production sound" folder inside the "mix" folder on the "camera" drive. See the exciting page on Data Management for more information.
The "Radio Play"
Sometimes, when we don't feel we've done an awesome job getting all the dialog cleanly, we do a "radio play". That's when all the actors stand around the microphone and we do all the dialog without the camera running. Sometimes we go to a quieter place to do the radio play.
I'd say the dialog from the radio play matches about 50% of the time. The other 50% of the time we either go so wide that we can't see lips moving or we go to someone's reaction or coverage instead. Ha! That's why you do coverage of reactions.
It's hard to sync in FCP because the timeline is only accurate to 1/24th of a second.
I suppose the most important thing is to make sure that all your audio is rockin' good. ;-)
A good boom op is the key to motion-picture production sound. To tell you the truth, especially these days, a production sound "mixer" (that is, the person who records the production sound) doesn't require nearly the skill a good boom operator does.
On a big-budget picture the boom operator (and the "cable-man" if there's a third person on the sound department) is responsible for not only handling the boom mic(s) but also the placement of plant microphones and wireless lavalier microphones. We almost never have the opportunity to place plant microphones (although back in the day when I was a production mixer I used to do it all the time, then again I was working on very boring art-house pictures too.)
Remember that thing about making sure the microphone is between 1 foot and 2 feet from the mouth of the person talking? That's all you have to do as a boom operator. Easy, right?
You have to do that while not casting any shadows on the wall behind the talent where camera can see the shadows. You have to keep the microphone and the boom both out of the shot too. You have to see where your microphone is in three - dimensional space and guess what it, and its shadows, look like on camera.
You have to make sure that you aren't making any noise or squeaks as you move the boom pole back and forth. You have to not hit anybody with the boom (you are virtually guaranteed to do that a couple times in your career — you will apologize profusely and nobody will trust you not to hit them on that set ever again, you'll hate that.) You have to make sure your cables aren't tangled and that you're paying attention to what the actors are doing and what the camera is doing.
Focus your microphone on whichever characters are on camera at any one time, but do try to get the "whole movie" when shooting a scene. Be good about moving the microphone back and forth between characters as they talk and be prescient about reacting to the actors should they change their performance so that you're on the right actor as they begin to talk.
(I find that many new boom operators tend to "overshoot" the heads of the people they're mic'ing. In other words, they don't realize that the mic is in front of the actor's face, but rather a little past the actor's head. This has to do with parallax or something and it takes a bit of practice to realize where the microphone actuall is when you're eight to twelve feet away from it.)
Keep track of when people (actors or crew) make any sort of noise over a line of dialog (yes, theoretically this is the sound mixer's job but remember you're a team).
And remember, you're the only people on set not working for Picture. Nobody understands you, nobody's interested in your problems, your problems are typically in direct opposition to their problems.
I think it was Robert Altman who insisted that his production sound mixer throw wireless lavaliers on all of the actors and not boom a thing. Well, if you record each lav to a separate track, and/or are a fantastic mixer, you can do that. You can do that if your boom operator has done a great job placing microphones on actors' bodies — keeping the mics both hidden and sounding good.
Hiding microphones is relatively easy. Making them sound good once you've hidden them can be a nightmare. Then when you're done hiding the microphone, you have to find a place for the transmitter. Lucky for us, transmitters are smaller and smaller these days. But some costumes can make hiding them very difficult.
Your biggest problems are clothing noise and the generally "meh" way a lav mic sounds against someone's chest. Other problems can include clangy jewelry, actors who hug one another in a take (because when they do so they manage to cover both their mics), and anyone who pounds their chest during a take to make an actorly "point".
A woman wearing a bra is probably the easiest to mic. The typical placement of the mic is on the inside of the bra right where the "cross my heart" part is — where the cups meet. You want to put the microphone on the inside because the bra itself will tend to hold the microphone up away from skin (which it would rub on) and away from her blouse (which it would rub on.)
For men, well, you have all kinds of different problems. If you have someone in a tie, you can try to put the mic itself on the inside of the tie (but not too close to the knot, otherwise it's underneath the guy's chin and the sound will be muffle-y). Or you can try attaching it with a couple pieces of medical tape to his T-shirt in such a way that it magically doesn't rub against his shirt or his T-shirt.
If you're working with an experienced actor you might try asking them where they typically get mic'ed when they're wearing a similar costume. This has resulted in eye-opening results for us in the past (Maggie Gyllenhall suggested an ankle-rig for her wireless mic transmitter when she was wearing a tight pantsuit, that worked great for her.)
If a guy is wearing only a T-shirt you might need to send him back to wardrobe to put on a tank top underneath the T-shirt for his microphone.
If you haven't noticed, hiding microphones on people is a black art I don't really understand. So I'll leave you with one last piece of advice about hiding microphones. In my experience the people who are the best at hiding them use only two pieces of tape. No more. They manage to figure out a way to slap two pieces of tape on someone and their microphone stays in place, doesn't rub, and manages to sound passably good for dialog.
Cell phones on set
There are two big problems with people carrying cell phones on set. The first is that they ring in the middle of a take. The second is that modern cell phones (I'm looking at you, Apple) make a LOT of electromagnetic noise and even when their ringers are silenced they'll screw will the wireless microphones.
Each sound mixer has a special tool to deal with cell phones on set. What sort of tool is that? It's a .45 automatic handgun hidden underneath the mixing desk. Now, I suppose I shouldn't have to say this but you, the sound mixer, do not shoot the person whose cell phone has rung. I cannot say this with enough emphasis. DO NOT SHOOT THEM.
Start with a member of their family.