Thursday, June 6, 2019

PAINTING EFFECTS OF LIGHT ON GLASS

SET UP YOUR OWN EXPERIMENT

This experiment is for you to observe for yourself the interesting distortions of light caused by glass and water. It will help you understand any reference you may be using for glass, chrome, or any other shiny surface. 

Pick one color for the ground and one for background. Here I have dark blue for background, white for the ground. Set up a glass object, and look at it from different angles. Notice how light traveling through the glass bends and distorts the color slightly. It also reflects objects around it. (In this picture, taken outdoors, reflects the trees in the yard on the upper third of the vase)
Also look for shadow below and behind the glass. 

NOTE: IF YOU ARE GOING TO PHOTOGRAPH YOUR OBJECTS, TRY NOT TO USE A FLASH.



Same vase, slightly higher angle.


Now add water to the glass. Again look at it from different angles, and note where the ground color and background color appear. 
Now add a stem or straw. You'll see how the water distorts and refracts light even more on the stem. It seems to disappear just below the water line, go off at an angle, then angle again and seem wider. Often the stem appears totally disconnected.Probably because of the convex curve of the glass. (Like our glasses make things appear larger)




Here I've changed the ground to blue to see what happens.


And now a black ground. Black and gray appear in such unexpected places. And there's still a lot of white.


 

Now try using just white for background and ground. The color in the water isn't nearly as dramatic, but the distortion is still there.  However, the shadows are very dramatic. They have the colors of the rainbow, as if split by a prism, and are very soft. And through the shadow you can see slices of light passing through the glass. (This was actually more apparent in life than in the photo)





Below is the photo I chose to use as a reference. (My photo from a series taken to demonstrate effects of light). I wanted a dramatic change in the colors, so chose a dark background against a white ground for shadow. (The dramatic change helps me to see the shapes I want to paint to indicate glass)


PAINTING THE VASE..MAKING A MAP

Why make a map? It takes about 5 minutes and saves you a world of pain later. This particular painting is not so complex, but is a good demonstration of how to do it. It keeps you from getting confused in a more complicated painting, especially one that has distortions in it.

Before I painted, I made a print of my sketch, about 5 x 7.


On that sketch, I made a "Map" to guide me through this painting. First I colored yellow pencil where I wanted the miskit to be. Then I colored green the spaces that will be pale tones with soft edges. 



So here is the final "map". The red indicates the darkest tones, mostly hard edged on one side, soft edged on the other. The gray are mid values. I didn't map the stems because I know they are pretty hard edged. 


First I miskit off the stems above the vase only . I put miskit on the areas that need a crisp, sharp white to show glass reflections.  (Yellow on my map) You can tape over areas with stems instead of miskit, if you'd rather. 


After the miskit is dry, paint the dark background. I want mine to suggest folds of fabric. I used cerulean, pthalo, and a little indigo for the darkest folds. It is painted wet into wet. So remember, if you paint it wet into wet, it will dry quite a bit lighter, so make sure you use enough paint. Dry it, then, if you want it darker, paint again. 

To suggest folds, paint the blues, then add darker color along a fold edge while it is wet. Then drag a dry brush along where there would be a highlight on the fold. Try not to make it look like a "stripe," but a wedge shape.

REASON FOR PAINTING BACKGROUND FIRST: You've established your darkest colors and your base color that will appear through the glass. It gives you a reference to work from so you don't get too dark or light as you paint the glass. 

COLORS USED: Pthalo blue, cerulean, Winsor blue, and violet or indigo. 


You don't have to wait for the top to dry before painting the shadow around the vase. Make a gray and have some other colors (green, pink, blues) handy to drop into it. Wet the shadow area and a little beyond it. Swirl in some color on the sides of the shadow, keeping some white spaces in there to indicate light passing through. Use the gray a little darker near the vase. Feel free to add some colors for interest. 


Dry the painting and remove only the miskit from the stems. 

COLORS FOR STEMS: Hansa light (or any lemony yellow) and cerulean, with French ultramarine added for darker areas.

Paint the green stems. This picture doesn't really show how green they are. Just observe how the colors and shapes of the stem change as they travel through the vase. The upper parts of the leaves are pretty medium. then they blur and become llighter as they go through the very top portion of the glass. Then they get darker and bluer until they reach the point where they enter the surface of the water. Then they get blurry, nearly disappearing, and are light colored again as you see them through the bottom of the vase. 

COLORS FOR GRAYS: a mix of whatever blue and yellow you've used, with some magenta or red.
Or just gray, if you prefer to use a tube gray.

Mix another gray, with a little more green in it. Then wet the area (you have marked off these areas in green on your map--pale soft edged color). Paint these soft edged areas a light gray with some green in it. (green is reflected in the water from the stems). 

COLORS FOR DARK VALUES: SAME as for background and greens.

When you have done those pale tones, you can work on your darkest values.(red on the map) Most of these darkest values are slightly lighter than the background behind it. Use the same colors as in the background.  I tend to work wet into wet to keep the edges soft. Then add your medium tones. (gray on the map)You will end up making adjustments as you discover more nuances in the glass that you didn't notice before. 


When you are satisfied, remove all the miskit. Soften some of the hard miskit edges, like the highlight on the middle left. I also soften the ring of the surface of the water a little.  I also went around the edges of the vase on the inside and cleaned up some edges. I darkened the stems on the outer part of the vase. 




GOOD POINTS BROUGHT OUT BY CLASS:

1. Don't like the pencil lines. Solution: before you paint, erase pencil lines in the area you are about to paint if it will be pale and pencil lines will show through. Leave just enough to be a guideline. 
2. What if I lose my whites? Solution: You can use gouache in small amounts to get back a crisp white edge. You can use a razor blade for a very thin white edge. 

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