1.5 | Using video keyer

After finishing setup:

• Switch the view in Director from SETUP to PRODUCTION

Introduction

The quality of the produced key is highly dependent on:

• the green screen
• the lighting
• the camera
• the position and clothing of the talents

Keying video

The video keyer is an easy-to-set-up real-time chroma keyer that you can use to key your video input.

1. Double-check that:
   1. the camera system setup matches the physical camera
   2. the input type of the video input for the compositing plane is set to "Internal Keyer" in the Director
   3. the camera system is routed to the machine
2. Go to PRODUCTION → Adjust → Video Keyer
3. Position a talent or a stand-in person on the stage, or else use a dummy model with hair, as well as a water bottle to set the transparency
4. Click "Initialize key" 
   Director grabs one image of the video feed.
   
   1. Click the "Background" button

   2. Draw on the image to select which colors are background and should be keyed out

      

      These are typically the flat green values - do not select the dark greens on the floor if you wish to get contact shadows.

      • It usually only needs a couple of strokes
      • If you want to recapture the image, just click "Recapture"
      • To delete all strokes use the "Clear" button
   3. Click "Initialize"
   4. Select "Show alpha on SDI output" to examine the result
   5. Refine the initial key by selecting more colors
   6. Click "back" when you are happy with the initial key
5. Refine the parameters to improve the key
   • Zoom in tight on the head of the model, and adjust the focus so that the hair is clearly shown. Then zoom back out again without adjusting focus

Initialize

Refine

Remove Background

Increases the domain of the selected background colors.

Adjust Foreground

Increases the domain of the foreground.

Add luma key

Adds to the key based on the pixel luma value.

Adjust Key Color Intensities

Red, Green and Blue

Allow adjustment of key intensity based on RGB pixel value to make red “repel” or be “insensitive” to keying, for example.

This is especially useful for preserving colors that are close to green, e.g. yellows. To preserve cyans, you have to reduce the blue intensity slightly.

Mask adjustments

To adjust the alpha mask from the internal keyer.

Gamma

Controls the gamma correction of the key.

Gain

Controls the gain of the key. A value of 0 equals a transparent plane, 1 is the default and values between 1 and 2 increase the gain.

Cutoffs

The Cutoff control helps to exclude a certain area that should be opaque from the keying process. This exclusion area is defined by the color saturation.

Luma adjustments

Edge Luma Correction

Controls luma range on despilled area - this blends back the original luminance value of the edge pixels, rather than using the luminance of the background pixel - carefully controlled, this will blend the edges in better to the background.

Shadows

The Shadow controls allow you to add shadows that exist on the evenly lit backdrop.

Add shadows

Controls the intensity of the key in the shadow areas. A value of zero gives no shadows - set a subtle value to get believable soft shadows.

Adjust contrast

Adjusts the depth of the shadows that are generated.

Despill

The Despill controls allow you to vary the background color removal from the foreground, adjust the foreground color range that is despilled, as well as allowing you to adjust the hue for the areas containing the spill.

Strength

Controls the strength of the effect. The default is 100% with full despill. Reduce the value to see if other colors than the background are being despilled as well.

Cutoff

Controls the range of colors that are despilled by color distance from the original background picked color. For example, yellow and light blue may also be despilled by default. Adjusting the Cutoff can exclude both colors from the despill range and so preserve the original foreground colors.

Hue

Changes the hue of the despilled area.