Deep Dive: Chroma Keying For Green Screens

Transcript:

In this tutorial, I'll guide you through using VidJam's chroma keying feature to remove backgrounds when working with green screens. I've set up a video grid layer filled with several sample videos and images that have a green screen background. To access the chroma key settings, open the layer's properties and navigate to the layer mask panel. Clicking on the Key Icon activates the chroma key function. The default settings generally offer a good starting point but often require some adjustment as every setup can vary. For clarity, I'll use a still image with transparencies, significant green spill, and it's fairly low quality. All of these make it a challenging scenario. First, I’ll reset all settings to zero to start fresh. The first thing you’ll want to do is to set the color to key out. Click on the Key color to open the color picker. While the color picker is open, you can click on the background image to take a sample of the color. I’ll click on the background green portion, then click ok to confirm my selection and close the color picker. The Min and Max sliders control the amount of the keyed color to remove. Colors varying less than the Min setting will be completely transparent, while those beyond the Max will be fully opaque, with intermediate values showing varying levels of transparency. In the image, the subject's veil and hair are tricky since they're semi-transparent. To maintain this detail, I'll keep the Min setting at zero and adjust the Max slider until it eliminates as much green as possible without affecting areas we want to keep visible. Watch out for green spill from bounced lighting, as overly aggressive settings might render parts of the subject, like her arms, transparent. Once you've keyed out the necessary areas while keeping essential parts opaque, you might still notice some green fringing. To address this, use the Deespill controls. I'll Start by maximizing the Deespill strength to see the effect clearly, then adjust the Deespill range to filter out the green without altering the original colors too drastically. Next, I’ll lower the Deespill strength until the colors look natural while still removing some of the unwanted green. You’ll probably have to go back and forth between the two controls to get it perfectly dialed in. Let’s try these settings with a video. It’s looking pretty good, but there's a visible outline, and since the video lacks transparency, I can increase the minimum setting to refine the edges. The skin tone is a bit off and looks purple so I’ll reduce the deespill strength. Chroma keying with Vid Jam can effectively remove colors, but the quality mostly depends on your setup. Make sure your green screen is brightly and evenly lit, free from shadows or wrinkles. You should also position your subject far enough from the green screen to avoid green light reflecting onto them like it did in the first example.