Part 4, project 2, exercise 2: Perspective – aerial perspective

Updated on 21 March 2017 (Harvard referencing and some contents).

7 November 2016. The project on aerial perspective (for an overview see The Editors of Encylopaedia Britannica (2015) and Tang (n.d.)) is going to be a challenge for me, since it requires paying controlled attention to several aspects, i.e. loss of focus, colour saturation and change in colour temperature. The required simple landscape would need to make do without the elements of linear perspective and in order to put myself in colour-only mood I made an excursion to Egon Schiele’s aerial perspective paintings (1890-1918, Austria), as e.g. in Fig. 1 below:

Figure 1. Egon Schiele: “Four Trees”, 1917, oil on canvas. Source: Egon Schiele (1890-1918) [Public domain] via Wikimedia Commons
The above work contains hardly any elements of linear perspective, apart from, maybe, the narrowing of spaces between the horizontal layers of clouds. The tiny mountain range at the centre (had to stop myself writing “at the back”, because of course on the canvas they are not) show all elements of aerial perspective, though: colder colours, loss of contrast and (comparatively) fading outline as well as a loss of colour saturation. And these, no matter how small the difference, are sufficient to allow the correct sorting of foreground and background and allocation of a roughly measurable distance between viewer and trees as well as trees and mountains. It is the viewer’s experience of the characteristics of the visible world and the associated workings of the mind, which do the trick.

The above is easy to interpret due to its known representative elements of a landscape, but when comparing e.g. Nik Harron’s (*1981, Ireland) completely abstract aerial perspective  “Untitled” (Harron, 2009) the system still works. There are colder colours, less saturation as well as loss of contrast and focus of nothing in particular and it becomes a believable landscape. It works due to the mind connecting with whatever knowledge I have of the world and it works, because it makes sense. Which makes me want to explore it the wrong way round (but for once I will resist the temptation!). In order to be able answer to the question in the study guide (“Is it necessary to combine all three to achieve the desired effect?”), I decided that it would be necessary to adopt a stepwise approach.

8 November 2016. Since the weather outside turned nasty within hours (sleet in masses), I chose a photo of a wonderfully dark volvcanic landscape from our 2014 visit to Iceland. It is absolutely reduced and appears very suitable for exploring aerial perspective.

So, what I did was, in steps:

1. Make a black brush drawing avoiding linear perspective, but using increasingly narrower lines towards the back
2. Reduce line colour contrast by painting over with increasingly lighter greys towards the back
3. Introduce colour, warmer in front, colder at back
4. Modulate colour saturation (enhance/fade) and colour contrast (enhance/reduce)

Here is the sequence (Fig. 2-5):

1. Brush drawing with black paint, increasingly narrower lines

Figure 2. Line drawing, narrowing

This on its own already provides an impression of space, helped by the standing rock cutting off the view of the gentle slope to the back of it.

2. Brush drawing changed to have increasingly less dark lines towards the back

Figure 3. Line drawing, less dark at back

The difference is not large, probably also because it was not easy to have very narrow lines painted with the brushes I have.

3. Introducing colour and contrast

Figure 4. Adding colour and contrast

10 November 2016. Volcanic sand and rocks look a very dark warm grey closeby, but increasingly cooler towards the horizon. This first layer of colour helped the painting to increase in depth, but it is clearly visible that any small mistake in choice of colour has a profound effect on the perception of perspective. This is particularly evident in the wide darkish horizontal strip behind the large stone in the bottom lefthand corner. It makes the rocky outcrop in the middle ground hover rather than sit on its hill. So it is clearly not enough to simply reduce contrast and colour saturation on a rigid recipe basis. It is essential to pay attention to the respective properties of all parts of the painting and balance the effects around each change.

4. Correcting saturation and contrast

By introducing a selection of purer warm hues used in mixing the above greys and adjusting tonal values, including some light and shade in the foreground and middle ground, as well as covering the sky with a dilute layer of greyish blue I intensified the differences between the different parts of the painting. Although linear perspective is present at no point in the painting, the space created by techniques relating to aerial perspective looks believable. I find that I make many of these adaptations subconsciously without referring to an external set of instructions.

Figure 5. Correcting colour and contrast

Overall I think that even the first line drawing using nothing but decreasing line width creates a working spatial composition. The same would apply to using staggered warm and cold coloured areas alone (similar to the third step), even if a landscape were inexistent. In order to be recognized as something derived from the real physical world, however, the above rules must not be broken. The human eye and brain are tuned into detecting the slightest discrepancy in information, a probably life-saving ability in our complex and not always welcoming universe.


Harron, N. (2009) An Aerial Perspective [acrylic on canvas] [online]. Private Collection, [n.k.]. Available at: [Accessed 7 November 2016]

Schiele, E. (1917) Four Trees  [oil on canvas] [online]. Belvedere, Vienna. Available at: [Accessed 7 November 2016]

The Editors of Encylopaedia Britannica (2015) Aerial Perspective. Encyclopaedia Britannica, London. Available at: [Accessed 7 November 2016]

Tang, I. (n.d.) Linear and Aerial Perspective: The Techniques of Linear and Aerial Perspective [online]. Inge Tang, [n.k.]. Available at: [Accessed 20 March 2017]


Part 2, project 3, exercise 1: Colour relationships – simultaneous contrast

Updated on 27 February 2017 (Harvard referencing).

15/16 May 2016. I still had a large part of the neutral grey ground prepared for the last colour experiments, so I used this for my exercise on exploring simultaneous colour contrast, i.e. the effect that colours appear to change relative to the colours they are seen against. Colours, which are close together on the colour wheel, appear more like one colour than when seen separately, while colours opposite to one another on the wheel reinforce each other. In the colours I chose (Fig. 1) the relative strength of this “cancelling out effect” is visible with the colours yellow, and both orange and green, which lie next to yellow on the colour wheel. While, for example, the yellow square inside the yellow-green frame (no. 3) is hardly noticeable as a separate colour, it is relatively clearly visible inside the green (no. 5) or dark orange (no. 2) frame. In producing the squares I had to take care not to leave any of the background colour to shine through at the boundary between each colour pair. The effect on the pair was instantaneous, at least to me. Even in the fourth square from the left, the tiny areas of grey between the yellow and green are so prominent that they shift viewer attention away from the colour relationship I wanted to test. In addition, it was very difficult to take a photo at all that was not either too dark or too bright, but then with shiny brush strokes, all of which have their own influence on the colour relationships explored here.

Figure 1. Simultaneous contrast in colours close to one another in the colour spectrum

Next I was asked to produce another (yellow) square, this time with its tonally equal complementary colour added, and to observe the effect (Fig. 2). To be honest, I would not know how to describe the influence. On the one hand, violet being the complementary colour to yellow, the combination works to enhance contrast in the pair. At the same time, making the pair tonally equal seems to work in the opposite direction. Colour contrast and tonal contrast appear to work hand in hand, as I would expect when thinking about it, but I may be wrong with my impression. In addition, I am not sure, whether I was completely successful in matching tonal values in the example below. No matter how much white I add, the yellow always seems brighter and there seems to be a limit regarding the potential of adding white in tonal adjustment (see explanation for this effect below).

Figure 2. Complementary pair of colours, contrast with tonal values made equal

Finally I was asked to produce square frames of a complementary pair and to observe their effect on a neutral grey centre in comparison with a white frame (Fig. 3). Since I was already using a neutral grey ground, I did not understand the instruction of having to paint an additional neutral grey centre, so I omitted that step. In order to see the effects the different frames have on their centres, I need to half close my eyes and carefully cover the squares I do not want to look at, since they are a source of distraction. To me, the grey square appears darkest and similar (but not equal) in the tonally similar complementary pair of yellow and violet, somewhat lighter inside the white and lightest inside the tonally unchanged violet frame which I added out of interest. When looking for information on the internet regarding the relative brightness of colours, it is the yellow-green receptors in the human retina that are the most sensitive (Kaye, 2014). Since the human brain tends to reinforce differences in order to separate information, it is to be expected that the brighter the square, the darker the centre will appear, and vice versa. The strongest colour contrast is produced by combining yellow and black (Perron, n.d.), so my observation regarding the white square is correct. This means, however, that no matter how much white I add to a colour, the tonal value of yellow/green-yellow may in the end be unattainable. This is my own interpretation and again I may be wrong, but it tells me that it is necessary to be very careful with the use and placement of yellow in a painting.

Figure 3. Complementary pair of colours on neutral grey

I am planning to explore colour contrast for Assignment 2 (separate posts to follow) and will try and keep investigating the subject throughout the preparations.


  1. Kaye, T. (2014) What color do humans see as brightest? [online]. Quora. Available at: [Accessed 16 May 2016]
  2. Perron, C. (n.d.) Colour Choices on Web Pages: Contrast vs Readability [online]. Carin Perron Colour Theory and Practice. Available at: [Accessed 16 May 2016]

Research point: Chevreul’s colour theory

Updated on 19 February 2017 (Harvard referencing).

3 April 2016. Michel-Eugène Chevreul (1786-1889) was a multi-talented, ingenious chemist in 19th century France, who, after having been urged to investigate the reason for the apparent turning grey of high quality yarn used in the making of tapestries, devised a groundbreaking classification of colours, a chromatic circle (Fig. 1), to serve as first-ever standard for weavers and dyers. It was and still is being adapted and extended by many contributors (Costa, 2009).

Figure 1. Michel-Eugène Chevreul (1861) Chromatic circle. Source: Michel-Eugène Chevreul [Public domain] via Wikimedia Commons

The original trigger for his research had been one observation where the nature of blacks appeared to change when seen next to blues and violets in tapestries. After doing some research on that major problem Chevreul came to the ingenious conclusion that colours set next to each other mutually influence the perception of their respective nature. Chevreul described this main observation as the Law of Simultaneous Contrast of Colours, stating that “In the case where the eye sees at the same time two contiguous colours, they will appear as dissimilar as possible, both in their optical composition and in their strength of colour” (emphasis added by me). It was first published in an English language translation of his 1839 book, “The Principles of Harmony and Contrast of Colours and their Application to the Arts” (1855) (Roques, 2011, p. 4).
The above statement was interpreted by Chevreul as a tendency of the brain to enhance perception by exaggerating differences in lightness and hue, in particular along the common border (Roques, 2011, pp. 4-5, for the effect on lightness see top row in Fig. 2 below). The same works also for the bottom image in the same illustration. In the row of increasingly dark stripes the different borders to the left and right of each stripe will make them resemble “channelled grooves more than plane surfaces”. This effect is known as “Chevreul’s illusion”.

Figure 2: Redrawn detail from original by M.-E. Chevreul (1839) Illustration of the contrast of lightness. Source: Georges Roques after M.-E. Chevreul (1839) [Public domain] via Roques (2011)

When the law is applied to hue, the following effects are observed: Placing side by side narrow strips of different tones of the same colour or strips of the same tone in different colours influences both the perception of intensity (contrast of tone) and optical composition (contrast of colour) of each colour, hence the name “simultaneous contrast of colours” (Roques, 2011, p. 6).
The basis of the perceived modifications depend upon the concept of complementary colours first observed by Buffon in 1743 (e.g. after staring at a red dot  for some time, it will appear green when moving the eye to a white sheet, Roques, 2011, p. 7) and observations by Hassenfratz regarding coloured shadows created by the simultaneous use of two different light sources (Roques, 2011, p. 7). Chevreul considered, in line with his observation for lightness, that complementary colours are those which are the most opposed. Exaggerating differences in this context means that the brain will add to each of the juxtaposed colours a little of the colour complementary to each. A white pattern on coloured grounds will thus appear tinted with the colour complementary to that of the ground. Adding some of the background colour to the pattern influenced by the complementary colour will neutralize the effect. And, importantly, juxtaposing complementary colours has the effect of enhancing each other, since to each is added some of itself (Roques, 2011, pp. 8-9).While the basic physical mechanisms of colour perception are not disputed and Chevreul’s explanations are supported by findings in neuroscience, there exist several conflicting theories regarding the mutual influence of colours and their effect on the perception of colour in art (Roques, 2011, p. 9), while a main point of criticism is that according to modern standards Chevreul confused additive and subtractive mixing, the former referring to mixing light, the latter to pigments and which are incompatible (Roques, 2011, p. 10). It is also important to remember that the observed effects depend on the size (area) of the coloured samples. In cased the samples are very narrow, the colours will “fuse” to be perceived as an average between the two juxtaposed colours (Roques, 2011, p. 11).

Chevreul’s work, increasingly so as he moved from pure to applied science, was of immense interest for whoever used colour at the time. Since, however, many workers of the time became acquainted with Chevreul’s theories in a second-hand fashion there were some misunderstandings transported regarding their true nature and some artists adopted a style of painting based on misinterpretations (Roques, 2011, pp. 12-13). Interestingly it was mostly artisans, and not painters, who appreciated Chevreul’s findings when solving practical problems. Painters were only interested in the enhancing effect of juxtaposing complementary colours and tended to ignore the unwanted effects in other colour pairs. Among the painters interested in Chevreul’s findings was Eugène Delacroix (1798-1863, France) (Fig. 3). The example below is a good example of applying complementary colours, see especially the flags on the ground (Roques, 2011, p. 16):

Figure 3. Eugène Delacroix: “Entry of the Crusaders into Constantinople”, 1840, oil on canvas. Source: Eugène Delacroix (1798-1863) [Public Domain] via Wikimedia Commons
Despite contrasting opinions it is obvious that many painters deliberately applied their knowledge regarding the use complementary colours, e.g. Impressionist Claude Monet (1840-1926) or Impressionist and Neo-Impressionist Camille Pissarro (1830-1903) in the following painting, where the juxtaposed greens and reds assume a great brilliance. He even went as far as taking in Chevreul’s advice to pay attention to the effect the colour of the frame has on a painting.

Camille Pissarro: “The Red Roofs”, 1877, oil on canvas (source: Wikimedia Commons)

During Neo- and Post-Impressionism painters became increasingly interested in the organisation of colours on the canvas. Among these, Neo-Impressionist and theoretician Paul Signac (1863-1935) and Georges Seurat (1859-1891) were most avid in their application of Chevreul’s colour theory, especially when “optically mixing” by placing small dots of complementary colours next to each other. According to Roque (p. 18) there was another misunderstanding at the base of their idea: rather than enhancing the respective complementary colour, the effect would be one of averaging them out, since they did not take into account Chevreul’s warning of not confusing contrast and mixing, the presence of which depends on the size of the sample of colour. The luminosity remains in their paintings, because the dots are big enough for optical mixing NOT to work (Roque, p. 19).

Georges Seurat: “The Seine and la Grande Jatte – Springtime 1888″, oil on canvas (source: Wikimedia Commons)

Vincent van Gogh (1853-1890) was another painter with a keen interest in colour theory. Since he had a great liking for yellow, many of his paintings have juxtaposed a large proportion of the complementary colour, violet, e.g.:


Vincent van Gogh: The Café Terrace on the Place du Forum, Arles, at Night, 1888, oil on canvas


Roque, on p. 21, discusses also van Gogh’s description of the ideas behind the famous painting of his bedroom, on the base of which was an interest in transporting an impression of rest by the selective use of colour. To this end van Gogh used both the contrasts of complementary colours AND the same hues in different states.

Chevreul’s ideas continued to be of interest with the beginning of abstract art. Since the latter artists has a particular interest in the organisation of colour on the canvas, his theory helped them organise their ideas. Foremost among these was Robert Delaunay (1885-1941), who used it to systematically structure his abstract paintings. His intention was to capture colour vibration and transport it to the eye of the viewer by applying a phenomenon which Chevreul called “mixed contrast”: Seeing one colour, followed by the illusion of its complementary, superimposed on the colour of another object introduced at a later point in time.

Robert Delaunay: “Le Premier Disque”, 1912-1913, oil on canvas (source: Wikimedia Commons)


Despite an increasing tendency to challenge and replace Chevreul’s ideas with newer findings, they are still in use as a basis of teaching colour theory today (Roque, p. 24).


Costa, A.B. (2009) Michel-Eugène Chevreul. French Chemist [online] Encyclopaedia Britannica. Available at: [Accessed 3 April 2016]

Chevreul, M.-E. (1883) Chromatic Circle [n.a.] [online] Linda Hall Library, Kansas City. Available at: [Accessed 19 February 2017]

Delacroix, E. (1840) Entry of the Crusaders into Constantinople [oil on canvas] [online]. Louvre, Paris. Available at: [Accessed 3 April 2016]

Roques, G. (2011) Chevreul’s Colour Theory and its Consequences for Artists, Colour Group, Great Britain. Available at: [Accessed 3 April 2016]