You are here

Computer Editing: Multi-Camera Editing

Computer Editing: Multi-Camera Editing

Here are some helpful hints for editing multi-camera footage into a finished production.

Here are some helpful hints for editing multi-camera footage into a finished production.Imagine for a moment that you plan to tape an event with three camcorders and edit the three shots together into a single seamless production. With the help of some friends, you position three cameras in the auditorium and roll tape as the curtain rises.

Combining those three tapes into one may be more challenging than you had anticipated. This article will teach you how it's done so you can make magnificent multi-camera edits.

ACT ONE: Gathering Footage

A successful multi-camera edit starts at the shoot. Before your camera operators start recording, make sure each tape is clearly labeled with the production, camera and reel number. For clean audio, it's a good idea to take a feed from the auditorium mixer. Feed it into Camera 1 as your primary sound recorder. You should also make sure the on-camera mikes are active on Camera 2 and 3 so all your tapes have soundtracks. This will help later when it's time to sync the reels.

As the director, use a wireless intercom system (available at Radio Shack) to make sure your camera ops keep the shots varied and as a result don't have any stretches where you have three closeups of one actor, and no coverage of anyone else on stage. At intermission, stop and re-start your cameras to save tape, but other than that, run your cameras continuously from a few minutes before the opening music until after the audience applause dies out.

Then, take all your great footage to your computer room to edit together a multi-camera masterpiece.

ACT TWO: Building Your Timeline

Your first chore is to launch your video editor and commence digitizing your footage. Remember that running three cameras produces three times the footage of a single camera.

Make sure you have plenty of free hard drive space on hand. If you're digitizing at DV resolution, (720x480) each camera will generate roughly 13GB of data per hour. Multiply that by three cameras and it's easy to see why storage is an important issue when you're doing multi-camera editing. Another critical issue is the size of the actual files on your hard disk. The maximum file size your hard disk allows you to capture may be considerably less than 13GB. For example, Windows 95 may be limited to 2GB files and Windows 98 may be limited to 4GB, forcing you to capture footage from each source tape in chucks that you will re-assemble on the timeline. See the Size Matters sidebar for more information.

The key concept in multi-camera editing of real-time events is stacking your clips on successive timeline tracks, then dragging them until each track is in perfect sync with its neighbors (see Figure 1).

Synchronizing Your Footage

A shot-syncing shortcut harkens back to film crews who filmed visuals and recorded audio separately, a process known as "double-system" recording.

Filmmakers realized that a sharp sound combined with a visual marker would make syncing up a soundtrack easier in post-production. Thus, the clapboard was born.

At the beginning of each take, they would film a wooden slate that contained production information. Attached to the top of the slate was a hinged stick. When the camera and sound crews called "speed," indicating that everything was rolling correctly, a production person would jump in front of the camera(s) and bring down the hinged stick with a hearty clap sound.

In the edit bay, they synchronized the sound of the clap and the visual of the stick, and the sound wound up in sync with the picture.

Today's video cameras are so adept at recording sound on a single system, that a clapboard isn't really needed. But some kind of synchronization cue can be a big help if you know you'll be editing multi-camera productions.

One sync trick comes from the wedding industry, where videographers and photographers traditionally work side by side. You can use a still camera flash to synchronize multiple video cameras. At the start of the production, when all cameras are rolling, have someone walk across the stage, point a flash camera in a direction where all the video cameras can see it, and set it off. In the post suite, the flash will typically occupy a single frame, and if you line up the flash points of all the camera tapes - you're in sync. Of course, you can get the same results with many quick-action events. In a pinch, having a production assistant walk in front of the stage and flap their arms up and down can be just as effective as a flash or clap. The point isn't the synchronizing action; it's being able to locate the same moment in time on all three cameras.

Sound can also effectively synchronize the footage, a task accomplished easily with a handclap or a clapboard clap. Since most editing applications display the waveform of the audio on the timeline, visually lining up the distinctive peak from a sharp sound, such as a clap, is easy.

Modern camcorders, provided they are powered correctly, run at rock-solid speeds, so once you establish a sync point, it should hold until somebody turns off, stops or pauses any of the cameras. DV footage is striped with time code, guaranteeing dependable synchronization.

ACT THREE: The Kindest Cut

OK, you've synced your three tracks, now it's time to start editing your show. When video clips are stacked on an editor, the clips on the highest tracks appear in front of the clips on lower tracks. So unless you shrink the visible windows you'll only be able to see one video track at a time.

If you have tons of time for editing, it's possible to shrink all three video tracks into quarter-screen sizes and position them so that you can see them simultaneously. It's a cool technique for creating a virtual monitor array but it's extremely render intensive and time consuming.

If you just want to cut your program, without a lot of pre-rendering, it's much easier to simply turn your various video tracks on and off as you go through your footage. Usually, editor configuration allows that if you disable Track 3, Track 2 shows on the monitor. Disable 2 and 3 and you see Track 1. So, watching your various camera shots is as simple as clicking your video tracks on and off as you go through your timeline.

One good organizational approach to this kind of switch editing is designating one track as the master shot and putting that on your foreground track. This might be a wide shot showing the action across the stage. You will also need to select a master audio track that will run for the duration of the video. Make sure you unlink the audio from the video to isolate the streams (see Figure 2). Watch the footage all the way through using your track markers, noting where your closeups would be better. Then use your razor tool to cut the wide shots away, revealing the synchronized closeup from Camera 2 or 3 on the track below. Voil! You have a perfectly switched, error-free three-camera shoot (see Figure 3).

Another approach is watching each of your three tracks, and placing edit markers to denote either bad or good footage. Whichever approach you take, the final step is to take out your razor-blade tool and simply cut out the portions you won't use in your final program.

The real magic of computer editing is that if you cut out the shots from Camera 1 and Camera 2, leaving Camera 3, then decide that Camera 2 really held the best angle, you can grab and drag the various clip handles around and recover footage in a flash.

By trimming the in and out points, you can fine-tune your cuts between cameras so that each transition is precisely where you want it. And if you decide you need a dissolve, wipe or even a split-screen effect between your shots, you can do it in a couple of clicks.

Take a Bow

We're living in a time of amazingly affordable digital video-production tools, including a wide range of multi-camera capable, affordable editing systems. It's time to bring down the curtain on the past, when multi-camera editing was the sole province of TV studios and high-dollar production facilities. Today, it's for all of us. So, don't be afraid to change your favorite cue from "roll camera" to "roll all cameras.

Tags:  December 2001
Bill
Davis
Sat, 12/01/2001 - 12:00am