Converting colour photos to black and white using Photoshop

Presented by Pixalo - written by Steve

In this tutorial I am going to show you a few of the different ways of converting your images from colour to Black and White using Photoshop. As you are probably aware Photoshop offers many ways to achieve the same or similar results. By trying out the different methods shown below you will be able to decide which is the best for you to get the results that you hoped for. A couple of the methods here are very simple and if you follow the steps in order, none of these methods should prove too much trouble for even a complete novice.

I have chosen to use the same bright picture in all of the methods to demonstrate the different results that are achieved. I have also tweaked the images after the conversion to B&W using a combination of Curves, brightness and contrast to show the best possible results from each of the methods. The final versions are shown at the end of this tutorial for comparison.

First method - Desaturate

Load an image into Photoshop

Then go to Image > Adjustments > Desaturate (Shift+Ctrl+U)

Which leaves the picture looking like this

That’s it, it is a quick and simple method that is basically two steps but offers a limited result.

Second method - Lab mode

Open the image again in Photoshop

Now go to Image > Mode > Lab colour. It will appear as though nothing has happened but don’t worry about this

Now you need to go to your Channels pallet which can be found by clicking on the second tab in the Layers pallet, usually this is at the bottom right of the screen.

Then select just the lightness channel by left clicking on the lightness section. Your image should turn to black and white and your channels pallet should look like this.

We are not finished yet…the next step is to go back to modes and convert the image to greyscale.

Image > Mode > Greyscale. A popup box will appear and ask if it is ok to discard the other channels, select O.K.

And you should be left with this.

Third method - Channels.

Go back to your original image.

Go to the Channels pallet, here you should be able to see four selections. From the top they should read RGB, Red, Green and Blue.

By selecting one individual channel you are discarding the information from the other two, which should make your picture turn to B&W but make it look different depending on the channel you have selected. The amount of difference will vary quite a lot depending on your original image. Below I have shown the three versions I get by selecting each channel.

Red

Green

Blue

You should try each channel and decide which gives you the results that you most like, for this picture I chose the red channel but once you have decided go to Image > Mode > Greyscale, again Photoshop will ask you if it is O.K to discard the other channels. Select O.K and you are finished.

Fourth method – Using RGB to Greyscale action.

This method works well and also will introduce you to Photoshop actions.

When used like this they are quick and simple to control but if you become more familiar with them and learn to make your own, they become a very powerful, and time saving feature….more of that in another tutorial.

Go back to your original image again

Now go to your History pallet and click on the tab next to it that says actions. The pallet should now look like this.

Click on the little blue triangle, this opens up the list of available pre-set actions.

Scroll down the list in the box until you find the one that we want “Custom RGB to Greyscale” and click once on it, the icons below the pallet will now become active.

Select the Play icon.

The channel mixer control panel will appear and your picture should now turn to greyscale. You can now move the sliders to adjust your image until you get results that you are happy with.

Fifth method – Channel Mixer

This is really a simplified way of the method above providing that you have not created your own action with your personal presets already selected.

Go back to your original image again

Then go to Image > Adjustments > Channel Mixer

Place a tick in the box at the bottom left of the Channel Mixer panel where it says “Monochrome”, this will convert your image to greyscale and you can once again use the sliders to adjust the picture until you get results that your are happy with.

Now all you need to do is make any other alterations and adjustments to the image that you feel are necessary to achieve your desired result. In practice I have found that either the Lab mode or Channels have given me the most pleasing results but different methods do work better on different images. Unfortunately there is no hard and fast golden rule that can be applied, but if there were that would take away all the fun

Below are my results from the same image using each of the methods shown above and tweaked to the best of my ability to show the best possible output.