Today we are going to cover 6 awesome techniques to convert a colour photo into a black and white photo using Adobe Photoshop. This can be a wonderful way to breath life back into some of your older photos, and if you have colour lying around from film is another great way to bring some old shots back to life.

There are some really simple ways to convert colour photos to B/W but often the results are far from perfect, learning the longer techniques will bring far more pleasing results and allow a far greater level of control of tonal balance and you can tailor specific techniques for particular shots.

1. Converting to greyscale

This is the simplest rough and ready way to convert your colour to B/W, simply by going to ‘image/mode/greyscale

Although it does the trick it can leave a far from desirable result, all the colour information is removed from the shot, producing a smaller image size. This technique often tends to flatten the image. You can compensate by using the levels function, ‘image/adjustments/levels this will allow you to adjust the tonal balance and contrast.

2. Image desaturating

Using the desaturating technique retains the colour information and allows for tonal changes.

This is a better technique than simply converting to greyscale; you will still need to massage the shot for best results.

First desaturate the image ‘image/adjustments/desaturate another way to achieve the same result is to select ‘image/adjustments/hue-saturation then drag the saturation slider all the way to the left this desaturates the image in the same way.

The best way to adjust your shot that has been desaturated is by toning, you can discover more about toning photos by reading 4 techniques for toning photos in photoshop

3. Converting to LAB

Converting an image to LAB is still a very quick method of turning your colour photo into arty black and white; the results it produces are of good quality and often require far less further processing.

Select ‘image/mode/lab you will notice that the image is still in full colour but it is now in LAB mode rather than the RGB mode. Now select ‘window/layers to open the layers palette then select ‘channels. You will observe you now have four layers lab, lightness, A and B.

We need to discard one of the A or B layers it does not matter which one, either drag the layer to the bin or highlight the layer and click the bin icon. This technique produces a high quality black and white image that has better shadows and highlights then the techniques of using convert to greyscale or the desaturation methods.

4. The channel mixer method

Allowing far greater control over the entire image is using the channel mixer method. Using this method is very similar to using colour filters when shooting black and white film, or if your dSLR support shooting in black and white. Although it is a similar technique to using filters you have far greater control with the post processing method.

Reasoning for far better control than using the on lens filter technique is because you are able to use several filters on a single image. Furthermore using this technique not only allows for greater control over the final image it also does not discard any of the original colour information.

First we need to create an adjustment layer, select ‘layer/new adjustment layer/channel mixer and select monochrome in the pop up dialogue box. Default setting will be the red channel set at 100% and the other channels at 0%. This gives a similar effect as using a red filter on your lens with black and white photography.

Now you get to experiment with the channels, move the sliders and see what happens to the image. If you select 100% on either red, green or blue these all produce similar results to shooting with red, green or blue filters. Adjust each slider individually until you produce the desired effect you are looking for.

5. Increasing colour saturation

This is sort of an add on technique to the channel mixer method; use this for boosting components of the image before converting it to black and white. Select image/adjustments/hue saturation then in the pop up dialogue box select the colour you wish to adjust. 

Lets say for example you have a photo with sky if you adjust the blue channel you will end up with a far more intense sky when you convert the image to black and white. (Note the sky might look terrible in colour but when you convert to black and white this will change)

Experiment with the different colour channels and see the resulting effects when you convert to black and white. Remember to convert to black and white simply select ‘image/ adjustments/ colour channel and select the monochrome checkbox. This technique allows you to produce shots with bolder tones and you can always make further adjustments using the previous channel mixer method.

6. Film and filter technique

This is by far the most complicated of all the techniques but like anything that takes a little time to master often produces the best results. We will be working with two hue/saturation adjustment layers, one we are going to desaturate the other we are going to use adjustments to the hue and saturation of the filter layer.

This technique has strong roots in traditional film photography and is similar to using contrast-controlling filters on your lens. With this method we can achieve an amazing amount of control over our image to such an extent we can change the entire mood of the photo.
First we need to make our adjustment layer, select  layer/ new adjustment layer / hue saturation then when the pop up dialogue box appears select mode colour. This is the filter layer; so for usability rename the layer to ‘filter’

Our next step is to create our film layer, repeat above select layer/ new adjustment layer / hue saturation select ok now when the dialogue box appears slide the saturation bar all the way to the left this will remove all colour from that layer.

Now we are back to experimentation again, double click the filter layer so that it opens the hue/saturation dialogue box. Move the sliders around to see the effect it has on the image. We can become even more creative with this, open the filter layer again to display the hue/saturation box but this time select the layers drop down at the top and pick a colour channel. You can continue to play with the colour channels until you have reached your desired effect.

Colour saturation is by far the most tricky to get right, but once you have become familiar with how it works I am sure it will become your favourite method for converting colour images to black and white.

If you have any further questions or your own tips and techniques I would welcome you add them with a comment below. Until next time happy snapping.

Photo credits intro photo by e_phots