An Elephant a Day: Elephant No. 277: Hidden Faces Illusion

I was looking for something else when I was reminded of this type of optical illusion, so I thought I'd try it for today's elephant. Most of these are done with human faces, although there are also versions using animals.

In traditional hidden faces illusions, faintly defined human faces are scattered throughout what looks like an ordinary pastoral scene. It strikes me as being a bit like the Japanese art of yose-e, although in yose-e, the drawings are usually made up entirely of hidden figures.

The idea is obviously to find as many hidden human faces as you can. In the puzzle below, there are thirteen, which makes it one of the more elaborate versions.

Source: http://www.tumblr.com/tagged/hidden-faces?before=1329785762

Visual puzzles like this fall into the category of "ambiguous optical illusion", meaning that what you see changes according to your expectations. For the image above, your first instinct may be to see it as a landscape. However, if you are told that you need to look for hidden faces in the picture, you may be more likely to see a jumble of faces, rather than a more general scene.

An ambiguous illusion is part of a larger family of cognitive illusions, which rely on our tendency to make assumptions based on our subconscious knowledge of the world. Because of this, some people may have a natural tendency to see the components of an image, making it easy to see faces in the picture above. Those who tend to view a scene as a cohesive whole will in turn be less likely to find all the faces in such images. There is, in fact, an entire thread of psychological practice devoted to studying how people perceive such images, similar to the use of inkblots to test cognitive perception.

There are several sub-genres of the hidden-face type of optical illusion. Some, like the one above, are quite involved; others can be rather simplistic. Since I may produce one or two of the other forms in future blog posts, I won't describe them here.

Hidden animal illusion by Jonas Wetzky.
This illusion has at least ten animals—no one agrees on the exact number—and
relies on intersecting and shared lines to form the animals.
Source: http://www.moillusions.com/2007/09/hidden-animal-forrest-illusion.html

I wasn't sure how most people go about producing these types of drawings, so I decided to start by sketching out a generic scene. Coming up with a generic scene was actually the hardest part. Clearly, having lots of natural elements such as stones, trees, roads, rivers and so forth is a help, so I started by trying to make up some sort of landscape in my mind.

Unfortunately, I'm not very good at landscapes, so I didn't like anything I drew. Instead, I looked online for a likely scene I could use. This is the one I chose:

Source: http://www.telegraph.co.uk/earth/earthnews/3353917/
African-elephants-afraid-of-roads-because-they-mean-danger.html

I sketched the rough outlines of this drawing out on mid-range watercolour paper, then figured out where to hide the elephants. I thought twelve would be a nice number of elephants to include, but I actually ended up hiding thirteen elephants in addition to the elephant that is part of the original photograph.

Since these types of illusions often rely on shading as well as outlines to conceal the faces or animals, I gave each elephant only a general location, figuring that I could do the subtle shading later. Some of my first options didn't end up in the final piece.

I rubbed away a lot of the pencil lines, and made the rest as faint as possible, before I started colouring things in with watercolour pencils. I chose watercolour pencils because they often leave a remnant of the pencil line behind, even after they're turned into paint. I thought this might be helpful in maintaining the hidden elephant shapes.

Now came the tricky part. I needed to conceal the elephants without obliterating them entirely, and without making them so obvious that they weren't hidden at all. I did this by using leaves and other types of greenery over and around some elephants, and bones and shadows around others. To make the elephants blend in, I mimicked whatever types of pencil strokes, lines or shading I was using in that particular part of the drawing.

This part of the process took me over an hour, and was pretty tedious. In the end, however, I was very happy with the final coloured-in drawing.

To finish this off, I used a fine brush and plain water to activate the watercolour pencils and turn the pigment into paint. This was also tricky. I didn't want to go around the outline of each elephant in a way that would make it stand out too much, but I also didn't want to soften the edges so much that the elephants would be impossible to find. In a couple of cases, I added a bit more watercolour pencil to sharpen a few small details, because I actually lost track of one or two of the elephants while I was working on this.

There are thirteen hidden elephants in the final piece, plus the obvious one from the original photograph. I'm quite pleased with the final version, although it's by no means an expert example of this sort of thing.

Aside from the tedium of filling in the entire drawing with greenery, it was also rather fun, and I think I may make a few of these in future as personalized gifts.

Elephant Lore of the Day
In Sumatra—home to the highly endangered Sumatran elephant—there are regular jungle patrols. These patrols are normally carried out from the backs of Asian elephants, and are intended to check for animal poaching and illegal logging operations deep in the jungle.

Jungle patrols have also, in recent years, become a form of adventure tourism. For a fee, tourists can take part in a four-day jungle patrol through the jungles of North Sumatra, accompanying regular patrol teams on their rounds. Most of the elephants used in jungle patrol operations are wild-born, and many are former troublemakers that have been tamed and trained.

In this case, necessity seems to be the mother of invention. Faced with illegal logging activities and problems with poaching, Indonesian forestry staff decided to begin regular patrols. Because motorized vehicles were not as surefooted on jungle terrain as elephants—and, more to the point, because engine noise might warn poachers and loggers that the patrols were in the area—elephant-back patrols seemed the ideal solution. Not only did they make patrolling more effective, but they also solved the problem of what to do with troublesome elephants.

The unfortunate side of this is the fact that the formerly wild elephants have lost their freedom, and have likely endured unpleasant training. On the other hand, they are also now fed and cared for as important assets, and are less likely to be shot by either poachers or irate farmers.