Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member
I love blending modes. They're one of my favorite motion graphics design tools and a lot of my tricks are based around using modes. Well After Effects CS5 got two brand new modes. The first one is Subtract. Here I have some footage of some gears and on top I have footage of this abstract black-and-white graph, like that. And I want to blend them together using modes. I can either click on the Toggle Switches / Modes button here at the bottom or press F4 which is the keyboard shortcut and blend them together.
Previously we had a mode called Difference. Difference is kind of like Subtract, in that it subtracts the pixel values of one layer from another layer but it's an absolute value, and creates these strange intermediate grays. Rather than things just going to black, we will get these color wraparounds it, a bit psychedelic but quite often they really aren't all that pleasing. On After Effects CS5, they've added a new one called Subtract and Subtract does exactly what you expect it to do.
It subtracts the pixel values of the layer on top, in this case, the white lines against the black background, white being high value pixels, black being low value pixels, and subtracts those values from the gear, creating nice black lines underneath. This is how you expect Subtract to work. And a really nice thing about Subtract is that it even works in 32-bit floating-point mode. You can end up with values less than one as you subtract one layer from another. For example, if I go over here and hold down the Option on Mac or Alt on Windows to toggle into floating-point mode, and hover my cursor over this really black area, look in the upper right corner for the RGB values.
You see they have actually gone negative and the nice thing about that is that I then bring on another layer on top in Add mode or Screen mode, it can add those negative values and bring them back positive again. I haven't lost them forever. So it's a nice little blending mode that basically works the way you thought Difference was going to work, and you can use it in place of Difference when you are trying to do things like Difference matting. Again just to remind you, Difference or Classic Difference creates a psychedelic look, values wraparound, and they are greater than zero rather than going down below zero. Classic Difference just handles the blacks little bit differently.
You can't really see it most of the time. It's out time we got Subtract. Glad they put that in there.
Get unlimited access to all courses for just $25/month.Become a member
93 Video lessons · 34071 Viewers
135 Video lessons · 68259 Viewers
79 Video lessons · 24082 Viewers
350 Video lessons · 108277 Viewers
Access exercise files from a button right under the course name.
Search within course videos and transcripts, and jump right to the results.
Remove icons showing you already watched videos if you want to start over.
Make the video wide, narrow, full-screen, or pop the player out of the page into its own window.
Click on text in the transcript to jump to that spot in the video. As the video plays, the relevant spot in the transcript will be highlighted.