CH 8 Visual Perception

CH 8 Visual Perceptions

            A world without color.  1 in 10 men are colorblind.

            Rods- distinguish between light and dark in our eyes

Cones- see color and tone

Colors help us experience

The “where” stream is the tonal pathway in the brain that helps us see.

Moonlight: The light of the sun reflecting off the gray moon.

            In the moonlight colors change, our eyes adapt, and our cones don’t register quite as well.  The Purkinje Shift is the phenomenon that green and blues tend to get lighter in dim and night conditions, while reds become almost black.  This is why we usually relate moonlight to blue.  Moonlight is actually redder.  What happens, is our rods make a small bridge with inactive cones and we suddenly “see blue.”   The key to painting a night scene is just observation.  Then get into a light studio and paint what you can recall, because photos can’t preserve it and neither can we paint in the dark without skewing colors.

Edges and Depth

            Edges will blur the farther they are from the focal plane.  Our eyes naturally adjust to what we are looking at so it is normal for artists to assume they should use all crisp edges but using blurred edges creates a sense of depth.  Use big brushes and wet on wet to create this feel for backgrounds in paintings. 

            I love the small examples James Gurney gives using 4 black squares and 4 gray squares to create different types of depth by shifting edges from sharp to blurry.

            When out at night or dusk the reason we can’t see detail very clearly is because our cones in our eyes that fill the fovea, are the central point at which we see small detail and since our cones identify color it thus becomes difficult to see detail.

Color Oppositions:

            The color theorist, Johann Wolfgang von Goethe, believe that darkness was not the absence of light, but rather black and white existed and all the colors in between, so blue was a lightening of black and yellow are darkened white (light) and so forth.  Did you know it was Goethe who discovered that when you look at a red square and then look at a white wall a green afterimage appears?  Goethe also had theories of what the cool and warm colors meant/feelings they provoked, like back in chapter 6 page 112.

Color Constancy:

            Red is always red right?  Not in the cubes on pages 144.  The bottom right corner of the first cube is the same color as the red in top right corner of the second cube.

How do we switch off context cues so that you see colors as they really are?  

            Answer: Color Isolation

There are several ways to do that.  Some artists use a special viewing scope.  Half of the scope is white and half is black.  Holes are punched on both the white and black side and then you can hold up the scope to single out colors and determine what they are.  Another nifty tip with these kinds of scopes is dabbing some paint next to the hole to see if it matches. J I thought that was clever. 

Adaption and Contrast

This subject talks about successive contrast, what happens when you look at an image, your eyes adjust to that color and it then affects the next thing you look at.  Also in a painting, a shadow affects the light side of things by usually being its contrast.  For example a shadow will be green making its light side appear red.

            5 factors that influence the appearance of colors:

·      Simultaneous contrast: the hue or brightness of background color induces the opposite qualities of what’s in front.

·      Successive Contrast: “Looking at one color changes the next color we see.”

·      Chromatic Adaptation: When illumination changes in color temperature the sensitivity of color receptors changes in relative proportion.

·      Color Constancy: local colors appear the same despite change in hue, value, or saturation.

·      Size of the object: the closer/larger an object is, the stronger the Chroma it will have.

Appetizing and Healing Colors:

            Healing colors range from soft greens and blues to violets.  Chromatherapy is the idea that colors have therapeutic properties for the mind and body.  Colors like red, orange, and yellow are used to whet the appetite for fast food.  Those who don’t believe in chromatherapy believe it’s just a placebo effect because it can’t be proven helpful with test.  Yet artists and designers tend to believe in the fact that colors have an emotional affect on us.