Cat vision
iris. Mysterious, intriquing.
One day, many years ago, I was relaxing in the summer sun in front of
our lovely old house. With me were our two cats, Mao and Myrtle. They
were as lazy as I was, "lolling" being the only word to describe their
movements. But where I favoured the sun, they both preferred the shade.
It was hot, I was nearly asleep, and just barely taking in the scene
before me through half-closed eyes. The cats were invisible in their
shaded patches. One of the cats got up and padded over to a new
position, again, in the shade. After a while it moved again. Also into
the shade. With my eyes half closed, where there would normally be an
undifferentiated garden path, I could see a meaningful pattern of light
and shade.
Slowly it became clear that the cats were seeing the garden in this
way, as a meaningful map of light/shade patterns. And that they
responded to this information by moving from shady spot to shady spot.
For me to see the pattern I had to close my eyes and observe the scene
through my eye-lashes, as it were. No such need for the cats though.
They have these specialised pupils which contracts to a narrow vertical
line, eliminating excess light while allowing good depth of field in a
narrow band from the twigs in front of them to the distant prey.
Unblinking. To enable this level of concentration, even blinking is
enhanced by a third eyelid, transparent, quick, clearing the surface of
the eye without obscuring the vision. What immortal hand or eye could
frame THIS fearful symmetry?
Something kept nagging at me, though. I knew that I was right, but what
was the payoff for the cat? What was the evolutionary benefit of such a
visual system? I could even identify a reason not to have such a system
in hunting animal. with our eyes half closed, we see less. It is most
amusing to tease a cat into hunting your hand... A fraction of a second
before it attacks, the pupil opens to its full extent, and if you pull
your hand away at this moment, the cat will leap, but into empty space.
Most embarrassing for the cat! But it needs to see every detail before
pouncing, as also in the momentum of its attack.
It was only in writing this note, that the benefit became clear to me.
Camouflage, first. As the cat moves from shade to shade, it remains
virtually invisible. And then, environmental. In Africa, the big cats
spend the day in shade, and in cold climates, they would seek out the
sunlight. Their superb visual system frees them to do this on a
virtually subconscious level.
All this has a lesson for the artist. Light and shade is the most
important of all skills that the artist has to master. And if we cannot
see light and shade, we can never render it. So the lesson of the cat
is, to see the clear and vital patterns of light and shade, half-close
your eyes.
Even in the 19th century a contemporary critic wrote,"Impressionism is
painting done through half-closed eyes."
Before them the classical artists used a device called a Claude mirror,
a concave mirror backed with black instead of silver. You can make this
at home by taking a flat piece of glass and painting one side of it
black. The other side is a Claude mirror. Looking into it we see the
world in enhanced tonalities... lights remain light, but middle tones
are shifted down towards the darks, very much like a Rembrandt
painting. Colours in the shadow also tend towards Rembrandt-like black
coffee.
A simpler way of achieving the same result is by looking at the sky
through an unexposed film negative, the way we look at eclipses,
except, don't use it to look at the sun so much as to look at cloud
formations. You will be surprised. The skies you see will look
remarkably like Turner skies (Don't forget that Turner idolised Claude,
who is credited with the invention of the black mirror.)
Ruskin, for all his admiration of Turner, abhorred the black mirror and
what he called "Rembrandtism". His reason was simply that to sacrifice
the glories of colour to get good light and shade was too high a price
to pay. We must have good light and shade, yes, but we must also have
good colour (Colour is the type of love, Ruskin said.)
The answer is not to use the Claude mirror to distinguish light and
shade but rather to use the natural method of looking through
half-close eyes, emulating that great hunter of nature, the cat. This
way we see, at the same time, true tonalities, and true colour.