03.05 Diagonal lines

Diagonals have more freedom of direction than the Cartesian axes - verticals and horizontals - because they are released from alignment with the image frame.

1. Diagonals are dynamic
Where Cartesians have a sense of stability or being supported against the effects of gravity, diagonals have the opposite - of falling under gravity. Diagonals thus have greater dynamism associated with a feeling of speed.

2. Diagonals convey depth
Diagonals predominate the man-made environments as a result of linear perspective: non-centred straight lines or edges receding into the distance appear as diagonal lines.

Diagonal lines are thus important elements for their ability to direct a viewer's eye: we are programmed to follow the line of a diagonal because we use it for depth determination, and for gauging the speed of movement of an edge falling under the effects of gravity.

As seen in frame dynamics, diagonals interact with the image frame to create visual tension. For single diagonals, visual tension increases proportionately with the angle between the diagonal and the long side of the frame up to a maximum of 45 degrees. For multiple diagonals, visual tension:

• has more 'weight' in the case parallel diagonals because the tension created by one diagonal with the image frame, is reiterated by identical tension from the other diagonals.
• is strongest when there are multiple diagonals at different angles, where there is tension created between the diagonals as well as the image frame.

In practice, parallel diagonals can be achieved from high vantage points using the compressing effect of a telephoto lens. Multiple convergent diagonals can be achieved in low or close positions with a wide-angle lens.

"Santa Trinità" by Masaccio, Basilica di Santa Maria Novella, Florence

Photograph Copyright ©2013 Loo Yen Yeo. All Rights Reserved.

Concept: Quadrilaterals (rectangle)

Description: Masaccio's 'Trinity' began the Renaissance, the first time that realism was expressed since classical antiquity. It was composed as a Trompe-l'œil: an illusionary chapel to be viewed specifically from this point - the original entrance to the lower church in Basilica di Santa Maria Novella. The constraining rectangular form with its restricted formal viewing point is essential to the success of Masaccio's use of perspective.

Title: Worshipper's view

Photograph Copyright ©2013 Loo Yen Yeo. All Rights Reserved.

Concept: Quadrilaterals (rectangle); Filling the frame (filling for presence); Frames within frames (enhancing perspective)

Description: (Close-up from the same position using the optical zoom function) Filling the frame to remove Trinity's grey surround increases its impact and enhances Masaccio's intended feeling of believable space.in which the humanity of the Father, Christ, the Virgin Mary and Saint John is portrayed.

Title: Volume

"Triumph of the Name of Jesus" by Giovanni Battista Gaulli, Chiesa del Gesù, Rome

Photograph Copyright ©2012 Loo Yen Yeo. All Rights Reserved.

Concept: Ambiguous (soluble); Delay (footprinting); Frames within frames (introducing movement); Frame shape (the 3:2 frame); Quadrilaterals (symmetrical)

Description: The viewer's eye is first captured by the detail and luminosity of the beautiful baroque creation, then the elongated parallelogram shape of the frame-within-a-frame moves the eye upward accentuated by the 3:2 image frame shape. Only finally, at the top of the picture is there a female figure indicating that the framed image is a reflection of the ceiling above.

Title: Taken to Light

03.10 Quadrilaterals - symmetrical and asymmetrical

Rectangles and their perfect forms, squares, are easily found as literal forms in man-made environments. They are highly unusual, implied or literal, in the natural world.

Just as ellipses have a special relationship with circles, where ellipses are commonly interpreted as circles viewed at an angle not perpendicular to their plane; so do members in the group of symmetrical quadrilaterals.

Rectangles (including squares)
These are only seen as such when viewed along the central axis: a line passing through the exact centre of the shape running perpendicular to its plane.

Parallelograms
These are observed when rectangles are viewed on a perpendicular plane passing through the diagonal corners.

Trapezoids
These are observed when rectangles are viewed on a perpendicular plane bisecting two opposite sides.

Asymmetric quadrilaterals
These are seen when rectangles are viewed along axes not passing through a point of symmetry. They would likely be resolved as two triangles.

Thus not only are the points of a rectangle highly constrained in composition, but the angle of its viewing is too. Precision is of utmost importance when taking an image of a rectangle, as misalignments with the image frame are glaringly obvious. As a possible consequence of the due care required, deployment of rectangular elements lend a sense of formality, of controlled structure; and slightly less so with trapezoids and parallelograms.

Santa Maria del Carmine, Florence

Photograph Copyright ©2013 Loo Yen Yeo. All Rights Reserved.

Concept: Delay (unexpected phenomena)

Description: This is what happens when inadequate clues are provided; one doesn't know what the picture or lines mean. The viewer is unlikely to be able to resolve the ambiguity of the image and will move without understanding its meaning - the delay period to realisation becomes infinite.

Title: Zip-line

Photograph Copyright ©2013 Loo Yen Yeo. All Rights Reserved.

Concept: Delay (unexpected phenomena)

Description: This picture makes much more sense as there are now enough visual cues for the ceiling fresco by Domenico Stagi (1782) to be resolved as a Trompe-l'œil.

Title: Ceiling opening

05.11 Delay

Key elements of a picture's narrative can be compositionally arranged in a manner that they are not immediately obvious. This results in a slow reveal of the story; a phenomenon known as delay. The prolonging of the viewing process turns engagement with the image into a significant event - delay is about the experience of the viewer who is required to expend some effort, to be rewarded by the surprise of realisation. Delaying tactics include:

1. Spatial reorganisation
The embedding of a key element is achieved through misdirection - pulling away to sequester the important detail instead of stepping in to highlight it; and using geometries under Gestalt perception to lead the eye along a different route.

2. 'Footprinting'
Referencing a subject which is out-of-frame - its shadow, reflection, or person's reaction to it.

3. Unexpected phenomena
Where something turns out to be other than what it first appears to be, such as a Trompe-l'œil.

The trick to successful delay lies in the provision of adequate clues to bring about realisation.

A Greater Endeavour Uncovered

"That photography is truly a fine art has been proven for more than 100 years by a number of extraordinary photographers. The finest prints are always products of insight and excellent composition, subsequently carried through with impeccable technique."

Bruce Barnbaum in 'The Art of Photography - An Approach to Personal Expression' (pages 284-285).

That's it then. In one fell swoop Bruce Barnbaum has forced me to contemplate expansion of this project by pointing out that I may have put the cart of composition before the horse of insight. Drat! Actually this served only to crystallise what I've been coming to suspect (my wishlist on Amazon bears witness); that insight is the root of aesthetic communication.

I now need to plan the routes of reconfiguration.

Loo Yeo

The Bridges of Florence

Photograph Copyright ©2013 Loo Yen Yeo. All Rights Reserved.

Concept: Lines (literal); Lines (implication); Cartesian lines (horizontal); Perspective (linear)

Description: Non-directional light resulting from overcast skies produces a low-contrast scene where the contiguity of shape can be better appreciated i.e. the lines of the bridges are maintained because they are not interrupted by the casting of strong dark shadows, thus emphasising their horizontality. The horizontal lines of the bridges' edges extend into implied lines - the windows of houses on the right river-bank - through Gestalt's Principle of Continuity.

The feeling of calm is reinforced by the ripples, which themselves gain horizontality with increasing distance - a by-product of linear perspective.

Title: Arno Oltrarno

03.04 Cartesian lines - horizontals and verticals

Two types of line - the horizontal and the vertical - deserve special attention, because together they:

• comprise the Cartesian axes on an Euclidean plane (photographs and paintings are generally presented in two dimensions); and
• become the frame of the viewfinder.

Horizontal lines
These are the most comfortable for us to view. This is because our natural field of vision is biased towards:

1. scanning from side-to-side; and
2. perceiving horizontal depth,

as a consequence of the lateral arrangement of our eyes. Horizontal lines convey a sense of stability and calm, of having lower energy, of something coming to rest from the effects of gravity - the properties associated with a base-line. The horizon is the most common horizontal line which we are exposed to.

Vertical lines
There is a higher energy cost for us to perceive in the vertical plane. Scanning from top-to-bottom and perceiving vertical depth often necessitates a tilt of the head: a weighty structure whose stable articulation under gravity consumes not inconsiderable energy. Vertical lines convey a sense of movement, speed and energy: of something falling due to gravity or moving to overcome its effect.

Horizontals and verticals in combination
Horizontal and vertical lines complement each other because they:

• act as natural stops to each other's movements; and
• create balance, of an upright being supported by a baseline.

When using these Cartesian axes, attention must be paid to align them exactly with the image frame, because their easy comparison renders misalignments glaringly obvious.

03.03 Lines

The human eye scans in 'saccades': straight-line jumps between points in the image field. But if there is just a single point in the image field, then the eye will jump between that point and parts of the image frame.

As the distance between a sequence of points decreases, a line is formed. Lines are the second-most basic graphical element and the first element put to paper during illustration. Furthermore Gestalt perception's Principles of Continuity and Completion, based on the notion that the eye has a propensity to forge straight lines, imbues lines with the attributes of direction, angle, length and flow.

Photographically, lines are often implied when there is less control over the shooting environment. Lines which exist literally are predominantly the edges of objects - perceived by the contrast in tone and/or colour on either side of the edge.

Frescoes of the Right Transept, Basilica di Santa Trinità, Florence

Photograph Copyright ©2013 Loo Yen Yeo. All Rights Reserved.

Concept: Gestalt perception (continuity); Triangles (implication); Gestalt perception (proximity); Gestalt perception (similarity); Gestalt perception (common fate); Gestalt perception (completion); Balance (static equilibrium); Dividing the frame (simple geometric)

Description: The top of the vaulted arch (out of shot) forms the apex of an implied triangle by the Principle of Continuity, with its baseline at the cornice. Four triangles are contained therein: two actual ones, above two implied triangles of the chapel arches. The shadows and the altar of the Doni Chapel imply further triangles. Principles of Proximity and Similarity combine to Common Fate - completing the larger triangles of the chapels, and implying two more by the fall of shadows within them.

Title: Ascension

02.03 Balance

The concept of balance lies at the centre of visual composition. Balance is the establishment of equilibrium through the resolution of visual tension in order to give images harmony.

Static equilibrium
Balance is achieved through symmetry, where elements of equal weight are placed equidistant from a central point or axis - everything 'falls away' from this centre evenly giving a measured, uniform feeling. The possibilities for symmetrical composition occur more frequently in man-made environments.

Dynamic equilibrium
Balance is achieved through asymmetry, where elements are placed at distances inversely proportional to their weight from the central point or axis - flow of movement from the centre occurs at different rates, accelerating and decelerating, giving rise to a sense of dynamism.

In practice, the environment rarely provides us with perfect conditions, so the resolution of visual tension from multiple sources cannot be achieved in a formulaic manner, requiring us instead to resort to the use of developed intuition.

Imbalance
Harmony may not be necessary or even desirable in the visual expression of an idea. The unease from a sense of unchecked falling, of suspension, or of a lack of resolution, can increase the intensity with which emotionally-charged content is experienced.

So perhaps it would be better to say that the concept of balance, its presence or absence, lies at the centre of visual composition.

Cappella del Crocefisso, Basilica di San Miniato al Monte, Florence

Photograph Copyright ©2013 Loo Yen Yeo. All Rights Reserved.

Concept: Gestalt perception (closure); Circles and ellipses (implication); Gestalt perception (proximity); Gestalt perception (similarity); Gestalt perception (common fate)

Description: Inside the 12th century Florentine church of San Miniato al Monte, semi-circular Romanesque arches abound at its South-Eastern end. Grouped by proximity and similarity, the Principle of Common Fate is at play. The spread of light over the heads of Saints John Gualbert and Minias, depicted in the two large golden panels of the chapel, complete an implied circle begun by the chapel's vault under Gestalt's Principle of Closure.

Since common fate is in effect, one completed circle causes all the other circles to be completed.

Title: San Giovanni Gualberto's Redemption

02.02 Gestalt Theory of Visual Perception

The human eye has only a very small area where images are sharply in focus - about 3% of its central field. In practice this amounts to less than a hand's span at arm's length. So, we 'see' by building up a composite image of our surroundings; our eyes flick point to point in jumps called saccades, taking in small pieces of visual imagery at a time which our brain then puts together. When we look at a photograph or painting, the same process applies.

The spatial arrangement of visual components affect the inferences we make: concerning their relationships to each other, and how they might coalesce into a comprehensive entirety. Our eyes might capture discrete images of a trunk, leaves, roots and branches, and yet our brain recognise their relationships and present us with a 'perceptual whole' of a tree.

The way pieces of visual information or elements are 'placed' into a whole - an aspect of perceptual organisation - was studied by Gestalt (meaning "organised whole") theorists in 1920s Germany. Although some parts of Gestalt theory have not withstood scientific advance, its principles concerning visual organisation are still relevant today.

Principles of Gestalt Perception

1. The Principle of Proximity
Things which are seen together will be thought of as belonging together i.e. grouped.
Example: If a row four identical items has a larger space in the middle, it will be seen as two groups of two.

2. The Principle of Similarity
Things of which have characteristics in common will be grouped together.
Example: six alternating rows of blue and yellow balls will be seen as three groups of blue and three groups of yellow.

3. The Principle of Common Fate
Items grouped through their proximity and similarity to each other are assumed to behave as one, sharing the same fate. The eye will want them to move together, or stay put together. Anticipations of a 'Common Fate' can be used to create visual movement and visual tension.

4. The Principle of Continuity
The eye has momentum; once it is made to follow a path, it will try to continue along that same path. This principle predicts a viewer's preference for continuous figures.
Example: a sequence of points will be joined up by the eye to imply a line, or a curving line (which will induce an eye to follow it) leads the eye to an object placed beyond the end the line.

5. The Principle of Closure
The mind seeks completeness. It has a tendency to fill in missing bits of information to make a whole; to complete simple shapes. This is develops out of the Principle of Continuity.
Example: a curved line of constant radius with its ends closer together will be visually completed into a circle, or two convergent lines may have their other ends joined to complete a triangle.

6. The Principle of Area
If there are two overlapping figures, the smaller is perceived to be in the foreground, the larger the background. This idea explains how we perceive which of two objects is in the foreground (the figure) and which is the background (the ground).
Example: a net, formed of two sets of diagonal lines each at right-angles to each other, has a smaller blank oval outline in its centre. The oval will seen as the 'figure', and the net as the 'ground'.

7. The Principle of Symmetry
Areas bounded by symmetrical contours are seen as closed-whole figures, rendering the perception of symmetrical areas as 'figures' preferentially over asymmetrical ones. This principle is developed out of the Principle of Area.

8. The Principle of Segregation
For the 'figure' to be perceived from the 'ground' there must be sufficient difference between the two. This is derived from the Principle of Common Fate and the Principle of Area. Figure-ground images, like those of Escher, exploit this for their ambiguity.

These principles suggest how our mind creates groups and areas in the visual field - how each group has common properties internally, and how they might relate to other groups externally - giving rise to:

Concepts in Gestalt Perception

I - Concept of Emergence
The mind can join the dots. Groups, which alone do not contain sufficient information for the full context, can be brought together and their possible relations explored until the meaning of the whole emerges.

II - Concept of Reification
Lacking sufficient information, the mind will act to fill in the empty space. The Principle of Closure demonstrates this.

III - Concept of Multistability
Lacking sufficient information, the mind will spontaneously move between the possible interpretations. For example, an absence of enough depth cues will cause a figure-ground inversion.

IV - Concept of Invariance
Objects will still be recognised irrespective of orientation and scale.

Battistero Neoniano, Ravenna, Emilia Romagnia

Photograph Copyright ©2012 Loo Yen Yeo. All Rights Reserved.

Concept: Circles and ellipses (literal)

Description: In the realm of visual composition, implied shapes are generally considered more interesting than literal shapes. The UNESCO-listed ceiling mosaic of the Neonian (Orthodox) Baptistery in Ravenna, whose strong content - the Apostles wheeling about the medallion depicting Christ's baptism; the framing within frames of concentric circles; the bright harmonious colours; the spokes and radial sections of the periphery vectoring inward - provide the finest demonstration of an exception to a rule.

Title: Conformity

A Sunflower in Classe, Emilia Romagna

Photograph Copyright ©2012 Loo Yen Yeo. All Rights Reserved.

Concept: Circles and ellipses (implication); Single point (centre); Frame shape (non-bias patterns)

Description: Fields of sunflowers line the way from Classe back to Ravenna. This is a classic photograph where a normally static central placement of a single point, the flower's centre, lets the sunflower's pattern tell the story. Sunflowers owe their dynamic pattern to the Fibonacci sequence, which encourage the eye to trace clockwise or counter-clockwise spirals simultaneously.

Multiple concentric circles are strongly implied, and the central point of focus is accentuated by the radiation of bright yellow petals whose tapered bases vector mildly inwards.

Title: Mesmerising

03.09 Circles and ellipses

In terms of opportunities for visual composition in the natural world, circles occur less frequently than triangles. This is because the points which would imply a circle have much less freedom of position. Without the support of a curving edge or line, the composer would require:

• at least five points, because three points would be perceived as a triangle and four as a square;
• the points, and track of any curve, to be equally distant from a central point in space; and
• they would have to close enough to each other to provide perceptual closure.

Circles have an enclosing effect, tending to focus the eye inward towards their centre; therefore they are a powerful means of directing the viewer's attention into what they contain. There can also be a slight feeling movement along a circle's periphery which comes from its association with rotation.

Naturally-occurring circles include bubbles, the sun, the moon, and organisms featuring radial growth.

Ellipses, often interpreted as circles viewed at an angle, possess the same properties i.e. feeling of enclosure, and direction of attention inward to a focal point. Unlike a circle, ellipses have only two axes of symmetry and they have greater dynamism because the speed of visual flow changes - accelerating or decelerating - along its periphery.

Spring Showers on Ponte Vecchio, Florence

Photograph Copyright ©2013 Loo Yen Yeo. All Rights Reserved.

Concept: Depth (diluting depth); Perspective (tonal); Perspective (colour); Perspective (sharpness); Muted colours (contemplative)

Description: The presence of historic Florence is immediately felt due to the downplay perspectival clues.

• linear perspective - convergence of lines decreased using the zoom facility
• tonal perspective - diffused lighting lowers the difference between foreground and background contrast
• colour perspective - the lack of bright colours as worn by the pedestrians (by fortunate circumstance) and muted by lighting conditions, causes the foreground elements to recede, while the bright golden orb atop the Duomo appears to advance, compressing the viewing planes together. 
• sharpness - outlines of distant buildings are only slightly less sharp

Title: --

Tags and the 200 character limit

That's right. The first limitation I've come across in the blog is that the tag/label field has a maximum of 200 hundred characters only! Google doesn't anticipate that someone would use cross-referencing to the extent that I do.

So what's the way forward?

It's to prioritise the index/concept numbers (e.g. 01.02.3) over the concept names (e.g. Concept: frame shape). The concept numbers will be tagged as completely as possible; followed by the concepts by name, in relevance order. Not ideal, but the small 'bright side' is that the limit forces me to identify the priority order of concepts.

Orti Farnesiani's Terrace, Palatine Hill, Rome

Photograph Copyright ©2012 Loo Yen Yeo. All Rights Reserved.

Concept: Depth (strengthening depth); Perspective (aerial); Perspective (colour); Perspective (tonal); Diagonal lines

Description: Taken from a little nook on Palatino in Orti Farnesiani, this scene successfully incorporates depth-enhancing cues. Multiple interconnected planes: the garden wall on the right; the edge of a Farnesiani pavilion framing the left; the sharply-lit tree trunk; the cypress behind it; the pine in the centre; the terrace balustrade; the temples lining Via Sacra of Foro Romano beyond, and Il Vittoriano in the distance (on the left) are bathed in strong directional light

Aerial perspective (from atmospheric haze), colour perspective (warmer hues in the foreground, cooler hues in the background) and tonal perspective (higher contrast at the front, decreasing as distance increases) are at play. Viewing lines are directed in zig-zagging diagonals to the image frame, creating a feeling of dynamic energy.

Title: Hidden Terrace