Themes

 

Dialogue on colour

These are excerpts taken from a dialogue on colour carried out on the ISCML list (Indian Society of Indian Cinematographers’ Mailing List).

 Sunny Joseph:

 Friends,

 Just a few definitions related to Colour that we all know, yet....

 Chroma - Intensity, brilliance or purity of a colour [degree of saturation of a surface colour]

Hue - An actual colour, e.g. red, green.[dominant wavelength of a colour]

Tint - A variety of a colour, especially one made lighter, by adding white.

Tone - The lightness or darkness of a colour.

 How many of us consciously think of a colour in these 5 tangents?

How many of our Director/Cameraman/Art-director trios design their colour schemes taking all this elements plus the psychological impact of a colour in relation to a particular scene, emotional state of the characters etc.?

Did you know that:

Man first used colour 70,000 years ago?

Only raindrops of certain critical sizes can form a rainbow?

10 million variations in colour are known to the eye?

" Music provides the best analogy for colour [they even share a vocabulary with words like 'harmony' and 'tone'] and the attribution of colours to sounds is not uncommon among painters and musicians. It rarely occurs the other way round, although a chilling exception is to be found in Munch's account of how his painting "The Scream" was inspired. Tired and ill, he was watching the sun set over a fjord:

 " I felt a scream pass through nature; it seemed that I could hear the scream. I painted this picture - painted the clouds as red blood - the colours were screaming."

 Somnath:

Sunny, my understanding of color (or colour depending on where you are right now) extends to three attributes, namely, Hue, Saturation and Intensity where Hue, as you say is the actual wavelength of the light - perceived by the human eye as a particular color.

Saturation would be the amount of gray in the color - meaning whereby, if you take out all the "color" from any color, you will get a gray (one of the shades of the gray scale.)  Imagine if you will a gradation from left to right where the left most manifestation is one of the grays from the gray scale and to the extreme right is the color at it's most saturated - in between are all the other saturations of that color.  Which brings us to tonality.  Different colors show up as different tones in a B&W picture. (Green is lighter and thus higher than Red on the gray scale, for example.) Which is to say the when we bleed the color out of a picture; we get grays - or in other words, tones.  This is extremely important for us cinematographers.

Imagine two vibrantly different colors (let us say shades of orange and green) that equate to the same part of the gray scale.  For a B&W picture, it would be a disaster to juxtapose the two colors (for example if I shoot someone wearing a shirt of one of the above colors standing in front of a wall painted with the other color - you can imagine the effect.) So I would say that tone is a derivative of saturation.

Intensity is the amount of white or black in the color.  This is also of extreme importance to us cinematographers since the amount of light we decide to throw on a color will decide its perception by viewers.  Meaning whereby that dark red, red and light red (pink?) are the same hue and saturation but with different amounts of white or black mixed with the color or, you could think of it as different amounts of light falling on the red object.

Comments?

Take care,

Som

Sunny:

Somnath, It will be a highly flexible linguistics that we can expect when one talks about Colour. In fact, all this dialogue will enhance our understanding of colour. So cheers :-)

According to the modern scientific definition of colour, it is not legitimate to ascribe colour to an object, but only to the light reflected from it. However, it is a convenience, even a practical necessity, to assign colours to reflecting surfaces seen under customary types of illumination such as daylight or tungsten light. When we do so, we are referring to the capacity of a surface to modify the colour of the light falling on it. We should remember that an object has no single characteristic colour, because its appearance is affected by a number of factors, the most important of which are the quality and intensity of the illumination.

Saturation is not the grey in a colour, on the contrary it is the strength or vividness of a hue. [We, luckily agree on hue.] A red for example, can increase in saturation from a pale pink to a vivid vermilion. The term was originally coined by dyers to describe the strength of a dye. It is used to describe the purity of a colour - the quality which distinguishes from a greyed colour. [When you take out all colour from any colour there is no colour. You will get a grey, provided you are only talking about photographing/ recording that colour in black & white. In fact to preserve colour for more than a hundred years, is to shoot it, in B&W, in the original Technicolor way!! Or may be make primary colour separation negative in B&W, from the original colour negative.]

The C.I.E. [Commission Internationale d'Eclairage] distinguishes between colourfulness and saturation, defining the latter as the amount of colourfulness judged to be present in a visual sensation in proportion to its total brightness. So saturation is relative colourfulness. Judgement of saturation remains remarkably constant while overall brightness varies. Thus, suppose a green dress is seen in various conditions of {'white'} light and shade: its brightness will vary, and so will its apparent colourfulness, but the saturation will remain constant.

The less white [not grey] a pigment colour contains, the more saturated it is - a pure ultramarine paint can be desaturated to sky blue, for example, by adding white.

While, when you are talking about 'tonality' you are referring to the reflectivity of the object surface, which determines it to be placed in a specific point in a grey-scale.

[Refer Ansel Adams, Zone System]. When you talk about 'tone' in the context of colour, it is a colour differing slightly in any way from a specified colour ['a tone of blue']. And a colour that appreciably modifies another ['blue with a greenish tone'].

'Intensity' in fact is the measurable brightness of a light source and a synonym for saturation. Judgement of saturation remains constant in light or shade, but its overall brightness and apparent colourfulness will vary. [ The amount of light falling on a colour will not vary the perception of saturation!]

Hope this helps and not increases the confusion.

Suggested reading:

"COLOUR" Ed. Helen Varley, pub.by ME [Marshall Editions, London -1980

"COLOUR" by Alison Cole, pub.by Dorling Kindersley, London -1993

"A HISTORY OF COLOUR" by Manlio Brusatin, pub.by Shambhala, London -1991

"EXPLORING THE COLOUR IMAGE" Kodak

You can also reach an interactive website on Ansal Adam's Zone System at:

www.cicada.com