Digital Imaging Photoshop CC Tutorial

Photoshop Tutorial : color to black and white


There are a number of different ways of making a color into a black and white picture in Photoshop CC.  This one uses calculations and blend modes. If you’re used to using blend modes on layers, you will love this.

I am planning to enter Cee’s black and white challenge and this time it is hallways so I asked Midnight to model for me.  He reluctantly agreed. This won’t win any awards but I think Midnight is an awesome cat so I don’t mind.

Now the fastest way to make a photo black and white is to change the mode to grayscale (Top menu: Image: Mode: Grayscale).  You have no control and you get whatever you get.  In Midnight’s case, I got this:

Actually I’m ok with that picture as it has a nice range but I like to see if I can do better.  What I like to do is go to Channels and look through them one by one to see if anything grabs my eye.

So first the Red Channel.  On the Channel palette, I keep the Red Channel eye on but turn off all the others and got this.

On the red channel, the floor comes out a lot lighter.  It also seems to bring out more texture in Midnight’s fur.  If you’re happy with this, you can delete the other channels (green and blue) and then go to Menu: Image: Mode and change to Grayscale.

However, let’s check out what happens on the other channels. Next up is the green channel. The green channel looks a lot like the default picture when you go to Image: Mode: Grayscale without doing anything at all.

Now the blue channel. The floor is a lot darker on the blue channel.  It brings out the texture more in the flooring but because Midnight is black, the darkness blends in more with him.

So what does this information tell me? I like Red because there is good contrast between the floor and Midnight but it feels a little blown out to me.  So what I want is something between the Red and the Green channels.  I reject Blue entirely because in this case it is too dark.

So now we are going to Calculations.  Go to the Menu: Image: Calculations.  What Calculations does is let you layer channels on top of each other and use the blend mode between them.

I want my main layer to be the Red channel. It is closest to what I have in mind. Just like you would do with layers and blend modes, you want the man layer to be beneath. My bottom layer is Red so I set that as the channel in Src 2 as that is the basis of my image.

My top layer is Green so that’s the layer in Src 1. This is the layer I am going to use to darken my image just a little.

If you use blend modes, you already know you can use “Multiply” to have an upper layer darken a lower layer.  So under “Blending”, select “Multiply”  Now the Opacity in the Blend Mode is like setting the opacity of the top layer.  This is just like using layers except you’re doing it with two channels.  If you set the Opacity at 0%, you will see the bottom layer–in this case the Red Channel.

I am darkening the red channel a little so I am moving the Opacity to 30%.  It darkens the floors a little but not quite up to the level of the Green by itself.

Once I click ok, it creates a new channel called alpha.  I trash the other channels. When you delete the first channel, it will ask you “flatten layers”. I say ok. Then I continue deleting the other two channels.

Once that’s done, I go to the Menu: Image: Mode: Grayscale. It changes the image to a grayscale image and the channel will now read Gray.

You’re done.

Experiment around with the blend mode.  I usually use “multiply” to darken and “softlight” or “overlay” to lighten but you may have your own favorites.  In this case, I ended up with this. Not as contrasty as if I’d just gone with the red channel but a better contrast I feel than if I had gone straight to the grayscale mode.

(Yeah, I’m going to take out the highlight on the stepstool in the kithcne behind him but that’s not part of this tutorial, lol.)

Most of the time I find one of  the channels is a great black and white photo.  When I want to finetune, Calculations with it’s blend modes gets me there.



Note: I use the photography plan which is currently $9.99 a month in the U.S. as of 3/6/18 and includes the use of Photoshop CC 2018, Lightroom and more, including some mobile apps. I love this plan! I don’t know how much Adobe charges in other countries though.


Leave a Reply

%d bloggers like this: