What is an ‘anachromatic’? Trying to look it up in the internet gave surprisingly little information. Looking up ‘achromatic’ in Merriam-Webster brought up the definition ‘possessing no hue‘. It believe that the same, a scale comprising only of white, grey, and black. No hue.
In Oxford Art Online under entry ‘Colour ‘s stated: ‘The chromatic or hued colors include red, yellow, green, and blue. The achromatic or hueless colors are black, white, and the grays. All other colors may be described as perceptual combinations of these.‘
- In a first step I used acrylic paint (Liquitiex Heavy Body with titan white and ivory black).
It is quite amazing how many difference in tonal values can be obtained. In my second rows I tried to reduced the total number to max 20.
Laying side by side the middle grey at the white and at then black end the middle grey is perceived slightly lighter at the black end.
2. In a next step I was wondering about the scale in oil and the use of a different black pigment. I used Van Gogh oil paint in titan white and lamp black
Laying the middle grey color swatch side by side to the white and black end of the scale the result is the same as in acrylic: at the black end the middle grey is perceived lighter. Although I feel that the difference in perception in oil is somewhat stronger.
- This exercise highlights the concept of ‘Chevrel’s illusion’: That the tonal value of the surrounding space influences the perception in the viewers eye.
- The grey mixed out of titan white and black (ivory and lamp black) do have a slight blueish color shift. A feel a bit stronger with ivory black (acrylics). So not really a achromatic and hue less colour.
- The low and high end of the scale needs special attention in mixing as the perceived difference in tonal value is quite steep with only a bit of the other color.
- Mixing around middle grey is a bit different to the low and high end as more paint to mix is needed and to obtain equidistant tonal values.
- Oxford Art Online: Available from http://www.oxfordartonline.com [accessed 20 April 2016]