The Art Guild of Central Texas will have a double booth at the Apple
Tree Bazaar at the HOT fairgrounds November 4 and 5. The first 12
members to sign up will get two feet of booth width to display their
works (table and wall). You may bring more to replace anything sold.
Exhibitors may agree to trade one another table space for wall space.
The cost will be $10 per exhibitor (payable Nov 4) plus 10% of all
Call Gloria Meadows (666-2344) to sign up. If you can't reach her, call
Bill Franklin (741-0960) or email him (email@example.com).
You need to commit to at least one two-hour period tending the booth.
Please list which of the following slots you will be able to serve. You
may volunteer to fill more than one. Please come 10 or 15 minutes early
to ensure a smooth transfer.
Friday, Nov 4 12-2 (includes setup)
4-6 (includes shutdown)
Saturday, Nov 5 9-11 (includes setup)
3-5 (includes taking the booth down)
Art works must be delivered between 10 and noon Friday and picked up
between 4 and 5 Saturday. The physically able would be welcome to come
as early as 9 Friday to get the backdrop ready and help hang paintings
as they arrive.
If you would like to have a baked potato lunch (with butter, sour
cream, cheese and beverage) on Friday, 11 to 12:30, you need to call
Paula at 752-0316. Cost is $2.
The exhibit will be open 1-5:30 Friday and 9-4 Saturday. Since crafts
predominate, relatively inexpensive works are more likely to sell, but
you never know. Someone coming to look for inexpensive Christmas gifts
might just fall in love with your painting.
We also need to provide a door prize, not necessarily an expensive
one. If you have something to volunteer, let either Gloria or Bill
Bill began with an overview of the human visual
system, from the retina and its
receptors and first step processing cells, along the optic nerve to the
Optic Chiasam, where the right and left sides of our field of view are
split to send to opposite sides of the brain, to the Thalamus, where the
data is converted to signals resembling those of color TV, to the
Cortex, where the data is organized, recognized, and separated into B&W
and color portions, and finally to the Parietal Lobe for the "Where
System" and the Temporal Lobe for the "What System." The "Where
System" uses B&W information to determine location and motion, while the
"What System" uses color information to determine color and form.
(To see any of the thumbnail photos better, click on it to enlarge it.)
next part of the talk dealt with color perception. Humans have
three color receptors, referred to as Red, Green and
Blue, although they are all sensitive to broad and overlapping ranges of
colors, as shown at the left. We use the ratio of the responses of
these receptors to determine the color of an object. Color blind
people lack one type of receptor, almost always red or green. If
you are red-green color blind you may see 21, rather than 74 in the
circle at the right.
is possible to reproduce almost any color sensation by combining narrow
bands of light in the red, green and blue regions of the spectrum.
These "primary" colors of light are used by TV and computer monitors.
Overlapping circles of red, green, and blue light are shown at the left.
Printing is done best with pigments that absorb one of the primary
colors of light. Absorbing the red from white light leaves cyan,
absorbing green gives magenta, and absorbing blue gives yellow.
These primary pigment colors are used in color printing and paint mixing
as shown above on the right. Due to the limitations of mineral
pigments, painters have traditionally used red and blue, rather than
magenta and cyan, for primaries, but must also use cobalt violet or an
organic pigment to obtain magenta hues. A color wheel applying to
both light and pigments is at the right.
the break, Bill continued with examples of illusions in art that
Margaret Livingstone has explained in terms of vision research in her
book Vision and Art. The Hermann scintillating grid effect
shown at the left, is due to the center/surround cells in the retina and
the thalamus being much smaller than those in our peripheral vision.
changes in brightness are much easier to detect than gradual ones, which
allows artists to fool the eye into seeing greater contrasts
than are actually on the surface, as illustrated by the Seurat sketch at
Our eyes are drawn to contrasts in brightness or
color and to faces. If there are such areas that draw our
attention, we care little that other areas are fuzzy and bland.
The Renoir on the right is an example of this.
peripheral vision, though less precise than our central vision,
never-the-less provides a lot of form information to our "what system."
Livingstone uses this to explain the enigmatic Mona Lisa smile.
When we direct our center vision to her mouth, we see only the slightest
suggestion of a smile, but when we look at her eyes, our peripheral
vision see a big smile shape formed by her cheek shadows and her mouth.
in the relative positions of objects makes it hard for our "where
system" to locate objects, which can give rise to an impression of
motion, as in the flags in the Monet painting at the right.
can only see things sharply by directing our central vision to them.
Since we can't do that everywhere at once, sharpness everywhere gives
the impression of lack of motion. We see that in the Poussin
painting at left of strangely static chaos.
lines and smaller shapes give us perspective cues for distance so strong
that they overcome our conscious knowledge. The upper ball on the
grid at right seems larger, even though we try to ignore the grid.
It is actually the same size as the lower ball.
low contrast, fuzziness, and blue tint of haze act as cues for distance
also, as shown in this Monet painting of a foggy morning. Although
there are few details, we get a clear sense of looking across a river at
a distant city.
gives a sense of shape. Since light usually comes from above, we
interpret an object that is lighter above to be convex, and one that is
lighter below to be concave. Shading is our strongest clue to form
in a painting.
small shapes can be merged in ways that lead to a three dimensional
effect. Posters of such pictures generated by computers
were popular a few years ago. Monet used the effect in the
painting on the left during a period when he was obsessed with trying to
rendition of luminosity (value) gives a strong sense of reality
regardless of the colors used. Dorothy Johnston's zebra at the
above right is an excellent example of this. A B&W image of it is
at the left. Matisse did this earlier, but Dorothy does it better.
On the other hand, different colors with the
same luminance, such as the squares in the Mondrian painting on the
right, cannot be well located by our "where system," so they seem to
lines can give a sense of motion perpendicular to them. If you
click on the Leviant painting at the left to enlarge it and look at the
rings, you will probably see such motion. The Monet at the right
may give the effect of flowing water in the same way.
the "where system" is color blind, imprecision in applying color to a
strong B&W outline doesn't detract from our perception of the objects
portrayed. The Walkowitz painting of Isadora Duncan at the right
is an good example.
patches of different colors, but nearly equal luminance, blend to give
an average color. This was much used by the pointillists.
The Signac at the left has areas of the castle and the sky which blend
Bill doesn't claim to be good at using these
effects. Knowing how they can be used and actually using them are
not the same thing. However, he hopes with practice to get better
at it. Perhaps you too can make use of them.