Black and white is a genre as old as photography itself. Back then it was the only way, if you wanted colours you had to get out your crayons and colour the print. These days we do it the opposite way. We take a colour image and make it black and white.

Of course black and white means essentially that there’s no colour. But you can’t make a great black and white image by simply turning the saturation to zero. The colours are an important part of a colour image, and if you remove them you will have to compensate with something. And what is left when you take the colours away is contrast. To make a striking black and white image, we often have to increase the contrast, not only for the whole image, but also locally. This will enable us to emphasize our composition and focus on the shapes and patterns in our image in new and exiting ways.

One very useful way of manipulating the contrast of a black and white image is to adjust the brightness of individual colours. In Darktable, we have essentially three tools for this:

• Channel Mixer: Decide how much each of the red, green and blue channels contribute to the final image.
• Monochrome: Mimics the way coloured filters are used with black and white film.
• Color Zones: My favourite. Adjust the brightness of up to seven different colours in the image, and also decide the exact hues to adjust.

In the video below i explain how to make stunning black and white images in darktable.