Dialog Box

Tips for rookie video producers

by Scott Fegette

So you've got a DV camera lying around, and you've been wondering what to do with it. Perhaps you've even been enterprising and shot a few videos already but aren't happy with the results. Don't be discouraged, and certainly don't write off video as a medium. Video is a very powerful way to communicate messages visually and to accentuate rich applications and experiences. And you don't have to be related to Spielberg to squeeze good results out of consumer-level gear.

Here's some advice—in the form of three quick tips—that you can use to start pulling the best results out of your homegrown videos.

Note: This article originally appeared in the Edge newsletter.

Requirements

To follow this tutorial you may want to install the following software:

After Effects 7.0

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Adobe Premiere Pro 2.0

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Tip 1: Matching multicamera shots

You've just shot a masterpiece using two or three different cameras. But when editing it back together, you notice that the color and balance are dramatically different between each camera shot. How do you fix this? If you're familiar with the Image controls in Adobe® Photoshop®, you'll find that it's a quick process to pick up. Adobe After Effects® contains many of the same image control functions as Photoshop and adds the ability to keyframe-animate them over time.

Adjusting levels

Most shots coming from different cameras often have different balance and exposure settings, so the Levels dialog box is the best place to start in balancing them. Just like the Photoshop Levels dialog box, the After Effects version allows you to view a histogram of the tonal range of your image (in After Effects, your current frame) and adjust both the white and black points, as well as the gamma or midrange slider. The histogram is just a graph of the range of values in your image/frame, with dark pixels toward the left, bright pixels toward the right.

Histogram of a video image

First, make sure the white pixels in your images are a true white by dragging the right-hand arrow slider under the histogram to the left, to the point where the graph starts recording information. As the graph shows you where the lightest pixels in your image start, you'll see that as you drag the right-hand slider left, the image gets progressively brighter.

Next, you'll follow the same technique with the left-hand arrow slider, which represents your black point. Drag it right until it reaches the point where pixel information is recording in your histogram. Make sure, however, that you don't drag the sliders underneath wide areas of the histogram or you'll essentially be throwing out information in your darker regions. The general rule of thumb is to move the right and left sliders (black and white points) to the right and left edges of your histogram—essentially setting the black point to the darkest pixels and the white point to the brightest pixels in your image/frame. Finally, grab that middle (gamma/midrange) slider and move it a bit back and forth to see how stretching the midpoint to accentuate the lighter or darker regions of your image affects it. Try to ignore colors for this step; you'll get back to them later. The goal of adjusting levels is to make sure the luminance/brightness/contrast in your cameras' shots match.

Balancing hue/saturation

The second most important step in balancing shots is making sure the hue and saturation levels match more closely.

Although some tools have more advanced ways of addressing hue and color information, almost every editor/compositor has a hue or saturation control. In this case, we'll be using the After Effects Hue/Saturation plug-in filter.

Hue/Saturation slider controls

Bumping up saturation a little on washed-out cameras can often take you quickly into parity, but you may also need to adjust the saturation of a specific color channel.

For example, if one camera has a decidedly blue tinge, you could desaturate the blue channel a bit; this is usually available in the RGB (Red, Green, Blue) pop-up at the top of these controls. By default, most Adobe products' color and image correction tools work on the combined RGB image, but also allow you to work on a specific channel (R, G, or B) and alter only that channel's information without touching the others. It's often easier to remove a tricky hue cast by manipulating the individual color channels. Remember to be sparing with your tweaks and let your eye be the final judge.

Tip 2: Removing hum and noise from audio tracks

How many times have you shot that perfect clip only to notice that you hear a computer whirr or refrigerator fan in the background? Or even worse, during some very introspective and moody dialog, you're distracted by a 60- (or 50-) cycle hum from improperly grounded equipment that made it onto tape. It's a well-accepted maxim that even the most professionally shot video can be ruined by poor audio, so let's look at some ways you can address noisy hums and buzzes in your audio tracks.

Ducking levels

If there's little dialog or required audio, then you can often get by with ducking the levels (aka hiding the nasty bits) during periods of silence.

Use the mixer and automation to simply lower the track volume between words and speakers, and then raise it again when there's dialog. Since the noise you're ducking will still be audible during the dialog—you're just taking attention way from it during periods of silence—it could sound strange to hear the noisy hum return when people are talking. In these cases, try leaving a little bit of the noise in the silent/non-speaking parts of the clip.

Alternatively, if you can record clean audio with another device from another, quieter location, you can mix that into the silent parts to help take attention away from the ducking.

Parametric equalizers

The audio spectrum, from the lowest bass frequencies to the highest treble frequencies, is represented in Hertz (Hz). The human voice tends to fall between 85Hz for a low bass and 255Hz for sopranos, while music instruments fall both below and well above this range.

Equalizers are simply tools that allow you either to raise or lower the volume of specific frequency ranges while not affecting others, exaggerating—or removing entirely—certain ranges of frequencies. Most audio applications include some form of parametric equalizer—as an audio effect, plug-in, or feature. But if you're not an audio engineer or well versed in sound reinforcement, they're not very intuitive. Fortunately, there's not much to them at their roots.

Basic parametric equalizer in Adobe Audition

A parametric equalizer simply lets you specify a range of frequencies and either raise or lower the volume of tones that fall within that range. In Adobe Audition® the controls of the parametric equalizer are as follows:

• Frequency: the target frequency
• Amplitude (or gain): the amount you'll cut or boost the selected frequency
• Width (or Q): the width of frequencies that will be affected around your target

Note: Although the terminology used in your software or hardware unit of choice may be different, these three functions are essentially what define a parametric equalizer. Some cheaper/lower-quality parametric equalizers do not include a manual width control, however.

In Adobe Premiere® Pro, the Parametric Equalizer plug-in is actually a group of parametric equalizers that you can turn on or off selectively, to affect not just one particular frequency but up to five frequencies at the same time.

In this case, we want to lower the volume of a single frequency, say the whirr of a computer's cooling fan:

1. Enable the Parametric Equalizer and, next to the Frequency Bands, click the Band 1 check box (make sure the others are unchecked).
2. Find both a spot in your audio track that's mostly silence and a prominent amount of the noise that you want to remove.
3. Set the Parametric Equalizer controls as follows:
   • Q/Width control to 100 (so the equalizer will focus on a very narrow range of frequencies)
   • Amplitude control to roughly 75% of its highest value

Click the Preview button to play the audio file, and then sweep the Frequency Band 1 slider repeatedly from its highest to lowest range and back again. As you do this, at some point you'll notice the fan noise that you're trying to remove jumping out in the mix and getting quite loud. This means you've found the target frequency.

Pull the Band 1 Amplitude slider down carefully until the fan noise stops offending you. Watch the main graph closely, too; if you push the amplitude up or down too far, you'll notice it has a bell-curve effect on frequencies around it. Make sure to keep that spike as narrow as possible so that you remove only the tones you don't want.

You can fine-tune things by slightly adjusting the Q/Width control, to make sure you're removing only the tones you don't want, and by slightly adjusting the Frequency control, to make sure you're dead-center on the offending fan noise. With Audition's five-band parametric, you can work on up to five different problem frequencies. Just watch the graph and make sure that closely adjacent equalizer peaks don't collide and affect surrounding tones more than necessary.

Always keep in mind that you're cutting out frequencies with this technique, so be sparing with both the Amplitude and Width/Q controls—and be prepared to make some compromises to get the best overall results. There's no substitute for cleanly recorded audio, and any trick like this that attempts to clean things up after the fact will be inherently destructive in nature. Use it cautiously, and let your ear be the final judge.

Tip 3: Nesting comps and workflows

When you attempt video surgery, it's important to have a clear plan before going in. Processing video takes exponentially longer than still images, so having a streamlined way of working is mandatory. One of my favorite ways of working in After Effects is by chaining virtual workflows using nested After Effects compositions. As rendering video can have a very real impact on your time (and the available time of your computer, no less), I find this can help me manage a project much more easily than doing one-take compositions.

Say you've got a great piece of footage but the client asks you to resize it/zoom it in the frame a bit, add some film-style color timing effects to the whole thing, and then fly some motion graphics or titles in. It's tempting to do all these things in one composition the quick-and-dirty way, but when client reviews and revisions come in, you may find yourself duplicating your work quickly.

Nesting compositions together and isolating steps in your video processing is how you maintain your sanity:

1. Create a new comp for the resizing/zooming, and name it 01 - Reframing. Resize your footage and reposition it in this comp as needed.
2. Create another new comp and name it 02 - Color Timing and then drag in the 01 - Reframing comp. Add your color effects directly in this comp.
3. Create another new comp named 03 - Animation and drag 02 - Color Timing into that comp. Add your title animation and motion graphics into this comp, which, thanks to this structure, reflects all the changes you made in the first two comps.

Now this all seems pretty straightforward and obvious, but how is this helping you save any time? Say you need to proof the resizing to the client—they're very finicky about the composition of the shot—but don't have time to render all the complex color shifts and animation. Just render out comp 01 – Resizing and save time for everyone involved.

Perhaps your client loved the framing and motion graphics but wanted a slightly different color treatment. Go back to comp 02 - Color Timing, make the changes, and render it out without the extra animation on top. When you're done, just render comp 03 – Animation; After Effects will perform all those subsequent steps for you too. Your comps aren't cluttered with extraneous layers and stacks of effects to scroll through, and you can isolate any previous step in your processing quickly by just opening the right comp.

Now three quick tweaks may not seem worth the effort of nesting them, but say you're also keying out a green screen, doing primary and secondary color timing, rendering custom fades and burns, compositing some 3D rendered plates, and so on. As you get more complex with your video processing, following this nested comp methodology ensures that your projects always make sense and gives you the most flexibility for downstream changes.

I hope these little tips help in your next video project and, more importantly, inspire you to dust off that DV camera and start shooting video yourself.

Where to go from here

For more information about shooting video and editing it, check out these resources:

• Producing Video for the Web by Scott Fegette
• Flash Video Topic Center
• Adobe Developer Center