Using the SpectraMatte Key Effect in Avid
As you work with your different video projects, you will soon learn that you have to manipulate the key effect. In the past, editors have been accustomed to using a third party program in order to fully clean and manipulate their key effects and Chroma shots. If you're using an Avid program, however, it comes fully equipped with a highly functional and advanced key effect mode.
The SpectraMatte Key Effect in the Avid systems may seem complicated at first, but in the end it helps in making your work easier and more efficient. The SpectraMatte Key Effect is used for when you have shots using a Chroma or bluescreen backdrop. This allows you to isolate your subject and place a different backdrop video. With the Avid system, you can do it right in the program without having to export your clip to another post-production software. Here's how you can best use this helpful add-on.
Step 1: Prepare Your Clips
You will probably have two clips that you want to key into each other. Place your foreground clip on V2 or Video Track 2. This is your clip with the chroma or bluescreen background. Place your new backdrop on V1 or Video Track 1.
Step 2: Apply the Effect
Open your Effect Palette window and choose the Key category. Here, you'll find several key effects. Choose the SpectraMatte Key, and drag it onto your foreground clip - the one on V2 track.
Step 3: Edit Your Effect
Through the Effect Editor Window, you'll be able to optimize the effect. First thing is to make sure that the effect is set to key out your chroma or background. Click on the effect's default key color; your mouse will turn into a dropper. Then, drag the dropper into your chroma background, and it will automatically be keyed out.
Step 4: Control Spill
Spill refers to the background or chroma that has spilled over your main subject. Though you've keyed out your background, you will notice that the edges of your subject will still have a tinge of the chroma background. That means that during the shoot, the background chroma reflected on your subject's skin or surface.
To be able to control this spill, focus on the Spill sliders in the Effect Window. First, click on the SpectraGraph under Matte Analysis. Here, you can opt to find a color that will replace the shade of your chroma background. If your background was green, you can opt to replace green values here with another color. Then, proceed to the Spill slider, and adjust the Spill Saturation accordingly.
These are just some of the basic controls under the SpectraMatte Key Effect in Avid that will help you in working with chroma background. To best optimize your work, you can choose to experiment with the other functions such as the drop shadow and the luma control. But, listed above are all the basics you need to know to be able to use this Avid function.