3.5.3. Cyan toned image

3.5.3.1. Overview

Cyan is a nice color touchup for black and white images, this example guides you through how to make this with darktable and how to control the tone. You can choose any tone of your like for this tutorial...

3.5.3.2. Procedure

This procedure uses monochrome, channel mixer and splittoning modules.

  1. Image preparation

    Prepare the image for the cyan toned steps by adjusting the base settings such as exposure,black level, contrast etc. for a correctly looking image.

  2. Black and white

    Enable the monochrome module (Section 3.4.3.7, “Monochrome”) to make the image black and white.

  3. Add color tone

    This step selects the base tone of the image using channel mixer (Section 3.4.3.2, “Channel mixer”), we are going for cyan tone but you can choose any tone that you like here.

    1. Enable the channel mixer module

    2. Select the red channel destination and set the red color value to 0.7

    3. Select the green channel destination and set the green color value to 1.15

    4. Select the blue channel destination and set the blue color value to 1.15

    As you notice we mix blue and green color to get a cyan tone, we substract 0.3 from the red channel and add them to blue and green.

  4. Splittoning

    The result of the previous step does also add a color cast on highlights that we actually want to have white for a prettier result. We also want to add some blue color cast to the shadows in order to emphasis them. Module splittoning (Section 3.4.5.3, “Splittoning”) can accomplish this.

    1. Enable the splittoning module

    2. Select a blue/cyan tone for shadows and set saturation around 50%

    3. Set highlights saturation to zero, to remove saturation on highlights

    4. Set compression to zero

    5. Use the balance slider to tune the effect, our example uses a balance of 70/30