the dimension of light & dark

you might also be interested in these articles: what's special about grey? | where is middle grey? | the dimension of colour

The aim of this introductory article is to explore just one of the dimensions of colour space: the polarity of light and dark. We shall learn that the light-dark axis for illuminants (the white-grey-black axis for surfaces) is independent of the scale of colours and that there are significant differences when speaking about illuminants and surface colours. For an exploration of other dimensions of colour-space you should refer to the section on Colour Space.

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what's special about grey?

you might want to read the previous article: what's special about grey?

you might also be interested in these articles: where is middle grey? | what is a grey card?

Before reading this article you should already be familiar with the article entitled "the dimension of light & dark". Additionally we will refer to two colour-space models known as "Hue, Saturation and Lightness" (HSL) and "Red-Green-Blue" (RGB). There is little point in proceeding with the present discussion until you are familiar with the basic concepts covered in these two related articles.

Read more: what's special about grey?

where is middle grey?

you might want to read the previous article: what's special about grey?

you might also be interested in these articles: the dimension of light & dark | what is a grey card?

Nothing will ever reflect back 100% of the light that falls on it. Equally, nothing will absorb 100% of the incident light. There is no such thing as a perfect white or a perfect black. The best that can be achieved is approximately 90% reflectivity for the whitest white and about 5% reflectivity for the blackest black.

In practice a reference white comprises a ceramic tile, specially manufactured and calibrated with a known reflectivity.

Read more: where is middle grey?