Join Richard Harrington for an in-depth discussion in this video Using the Calculations command to create a selection from two channels, part of Photoshop: Selections (2013).
…If you thought using an individual channel to…create a selection seemed kind of useful, using more…than one channel is often a great way to…jump start the process and get incredibly accurate results.…Essentially, you can take two color channels and mix them…together using blending modes to make a new third channel.…This is often very close to a perfect…Alpha Channel and could just be selectively refined.…Here's how it works. Here's an example of using this technique.…
You notice that I extracted the background.…Remember, you can Shift Click on a Layer Mask to enable or disable.…But look at how incredibly accurate it was.…It actually knocked out the blue sky in the window, which is a great command.…And every little bump on the side of this building is accurately masked.…What I'm going to do is choose image calculations.…The calculations command has been around since the very first version…of Photoshop, and what it does is it combines two channels together.…
This is how you used to composite before you actually have layers.…
This course was created and produced by Rich Harrington. We're honored to host this content in our library.
- What are selections?
- Creating masks from selections
- Moving a selection
- Selecting with the Quick Selection tool
- Transforming a selection
- Using the Refine Edge command
- Selecting a color or tonal range throughout the image
- Making a selection with the Pen tool
- Saving a selection as an alpha channel
- Creating a selection from multiple channels with the Calculations command