Channel Mixer. It can be a scary tool for the new photographer. It is not a tool that is straight forward and simple to use. But, it is really not that complicated. RGB images are made up of 3 channels. One is red, one is blue and one is green. The Channel Mixer, is just that, it mixes these three color channels. There are many uses for it, but one of the most common for me is for converting images to black and white. In the film days, we used to use colored filters to change the tones of colors when making black and white images. A red filter would make blue colors darker and red colors lighter, yellow filters darken cyan colors while yellow colors are lighter. You can do the same thing with channel mixer.
In this example we are going to take a full color landscape image and apply a red filter black and white conversion. Open your file in Photoshop. I have already finished all my editing on this image. We begin the conversion by opening the channel mixer. go to image > adjsutments > channel mixer (or you can use the short cut on the adjustments layer like I did)
We begin the conversion by opening the channel mixer. go to image > adjsutments > channel mixer (or you can use the short cut on the adjustments layer like I did) Click the monochrome button. For this image I wanted to add a red filter, so i bring the strength of the red channel up to 100. I then dropped the green to 40, and the blue to 20 (play around with the seettings, these are not magic numbers. salt and pepper to taste.
Once you have the look that you are looking for apply the settings. Done. that simple. I have found that I really like the red 100, green 40, blue 20 for portraits and landscapes. I liked it so much that i have an action that runs it in one click.
Give it a try and let me know how it works for you.
Thanks for reading.