It wasn’t until I had posted my efforts to make images that show volume rather than ones that sit flat on the page or canvas that I began to ask myself where and how volume arose as a concept in art. I think this was triggered by reading Hockney’s 2001 book on the ways he believes some of the old masters achieved their remarkably naturalistic effects, but there are other questions too because even with an understanding of perspective and deployment of the various lenses to aid execution, the end experience of volume comes from an interaction between this two dimensional representation and a human eye and brain.

There is an obvious shift in the way art shows depth when linear perspective begins to inform practice. Far away starts to look far away by being small, and near is shown as much larger even if the painterly aspects of this, such as brightness and detail, don’t follow the rules of aerial perspective.

This seems to have been resolved quite suddenly and coincidentally at the time mirrors and lenses became more ubiquitous, and as many artists were also scientists, of course they used this new technology in their art. Mirrors and reflections start to appear in paintings, van Eyck’s 1434 Arnolfini Portrait and Diego Velasquez’s  1656 Las Meninas for instance. Detail starts to fit form, and perspectives become subtly inconsistent as lenses are moved to accommodate a different view point.

But who notices this other than a man who also pays attention to detail, and can recruit a mathematician to help figure out what’s going on? Hockney is at pains to say this is not cheating; the camera lucida, the camera obscura, and the epidiascope are tools in an artist’s armoury just as smart phones and digital gizmos are today. What matters is what you make of the marks these tools allow you to execute, and what those masters make of theirs is hats-off astonishing.

The underlying issue though is that these are still 2D representations that a viewer’s brain accepts as showing them a 3D image, and this requires both an experienced brain and a contract between the viewer and the viewed to be ready to suspend disbelief.

Child development studies tell us that until a child has experienced depth, it will not show any concern about crawling over the ‘visual cliff’, which is an experimental apparatus designed to tease out the way depth perception develops. Six months is the watershed, it turns out. Before that, babies will generally scramble unconcerned across what appears to be a huge drop; a little older and they are much more reticent. This video illustrates the set-up.

Other aspects of perception develop in the same kind of way – you learn linear perspective by discovering that the tall person is further away than you thought or that you can’t catch a helicopter in a net just because it looks tiny to your eye (I watched my cat doing that, although not with a net, obviously), haptic perception gives us 3D as we feel the shapes of objects and relate them to solidity.

By the time we are out in the world we know a distant bus looks very small, that small objects close by look larger than large objects far off, and that oranges are round even if they look flat in a picture book. These perceptions can be messed with though, take the Ames Room for instance where mathematics and art conspire to ‘alter relative dimensions’ and make some people feel quite sick:

I’d argue that 2D art is doing something similar only in this instance it’s using the brain’s own developmental structures to get it to collude in an untruth – the hill is a long way off, the box has sides and also an inside, and the people are round where people are usually round. It would not work if we refused to suspend disbelief or if the artist did not follow the rules of volume and perspective by giving us hints. The Gestalt* psychologists showed us years ago that our brains are more than happy to fill in gaps where gaps are not supposed to be, so all we need is a handrail to give us the confidence to perceive (not see because this is a psychological construct, not a direct physical event) what they want us to perceive.

So volume, along with many other things, is a function of the brain which uses what it knows about how the world works in conjunction with cues provided by the artist, and in the context of an understanding that disbelief should be suspended in this environment with this class of objects (art). People who lived in caves understood that their drawings were representational and that the tiny dots on the horizon were animals to be hunted. But if an unfamiliar object appeared – Stanley Kubrick’s black slab for instance scaled up and parked on their horizon – how would they perceive that? Close because of its size, or massive because it was large and very far off? Perception requires knowing, which probably accounts for Cezanne’s fruit being accorded volume even though they have quite a solid line around them. Lines demarcate, we know that so we accommodate artistic ones; and where there are no lines, and tones from an object blend into the surroundings as with Morandi’s still life paintings, we accept that too because the Gestalt principle of closure fills in the line for us.

The artists of the 15th and 16th century set a high bar with their lens enhanced detail but they also gave us more clues as to how to set a perception contract with viewers. If you build them, they will see*.

 

Hockney, d. 2001. Secret Knowledge. Thames & Hudson.

The Arnolfini Portrait by Jan van Eyck 1434. [online] Available at https://en.wikipedia.org/wiki/Jan_van_Eyck. Accessed 19 May 2020.

Las Meninas by Diego Velasquez 1656. [online] Available at https://en.wikipedia.org/wiki/Las_Meninas

The Visual Cliff Test – intro to psychology. 2015. Udacity. [online] Available at https://www.youtube.com/watch?v=YaZxQd26Q48. Accessed 19 May 2020.

Tales from the Prep Room – the Ames Room. 2011. Royal Institution. [online] Available at https://www.youtube.com/watch?v=EOeo8zMBfTA Accessed 19 May 2020.

Basket of Apples by Paul Cezanne 1895. [online] Available at https://en.wikipedia.org/wiki/The_Basket_of_Apples. Accessed 19 May 2020.

Giorgio Morandi 1890-1964. The Tate Gallery. [online] Available at https://www.tate.org.uk/art/artworks/morandi-still-life-n05782 Accessed 19 May 2020.

*For the principles of Gestalt psychology with reference to design, see this web page from User Testing: https://www.usertesting.com/blog/gestalt-principles

**’If you build it, he will come’ is from a 1989 film starring Kevin Costner. Disappointingly not the likes of Julius Caesar or at least Walter Gropius.