Alpha Channel Manipulations 101 – DaVinci Resolve Fusion Fundamentals

September 12, 2023

Learn the fundamentals of alpha channel manipulations, including tonal adjustments, blurs, and combining masks from VFX artist Bernd Klimm.


Compositing Basics – Manipulate Masks in Fusion with Blur, Tonal Adjustments, and Basic Math

In this compositing fundamentals Insight, you will learn the foundational techniques for manipulating an alpha channel: blur, tonal adjustments, and combining masks with basic math like subtract, multiply, minimum, and maximum. After understanding these foundational concepts, you have a better understanding of the parameters inside more complex keying plugins. You’ll be ready to start building more complex custom masks and have a deeper understanding of the buttons and sliders you’re manipulating.

Alpha channels/masks can come from:

  • Procedural extractions like keying tools or the magic mask plugin
  • Rotoscoping
  • Or delivered to you externally, such as from a VFX artist

Knowing how to manipulate your masks (soften, grow, clean black, etc.) using a few simple Fusion nodes gives you additional options in compositing and relighting operations – even if the plugins you’re using don’t provide those parameters.

While more advanced plugins are convenient, it is helpful to lay out how individual sliders are processed. It helps make the individual steps clearer, which helps your understanding and opens up additional possibilities to manually adjust the process. That’s why we start this Insight with the most basic principles first and then see how those are reflected inside the combined tools.  

In part 2 of the Insight, you will learn to build some more advanced custom edge masks with different properties, as well as draw your own masks for custom relighting.

Key takeaways from this Insight

By the end of this Insight, you should understand how to:

  • Soften or sharpen masks
  • Shift the edges of masks
  • Build your own edge masks
  • Combine mattes with shapes

The Fusion nodes covered in this Insight:

  • Blur
  • BrightnessContrast
  • ChannelBooleans
  • MatteControl
  • Rectangle
  • Bitmap
  • ErodeDilate

Related Mixing Light Insights

Questions or Comments? Leave a comment!

How do you like this breakdown for our everyday compositing tools? Are there other tools that we should take apart like this?

– Bernd

Member Content

Sorry... the rest of this content is for members only. You'll need to login or Join Now to continue (we hope you do!).

Need more information about our memberships? Click to learn more.

Membership options
Member Login

Are you using our app? For the best experience, please login using the app's launch screen

1,200+ Tutorials, Articles, and Webinars To Explore

Get 7-day access to our library of over 1,200+ tutorials - for $5!
Do you like what you see? Maintain access for less than $5 per month.

Start Your Test Drive!