Monday, October 3, 2011

Painting Reflected Light

Chimney Rock Shadows, oil, 16x20 plein air

Here's the plein air piece I did Friday evening.  It's not quite finished - I will have to do some tuning in the studio, but it's probably not going to change dramatically and it serves as a good illustration of what I talked about yesterday.
There is something of a "law" of light. It's about as close to a real rule of painting as you're going to get. It is this:
If you have warm light (ie sunlight or indoor incandescent light) then shadows will be cool.
If you have cool light (indoor north light, or cloudy overcast outdoor light) then shadows will be warm.

This refers primarily to CAST SHADOWS,.
(You know the difference, right?  Form shadows are the part of any object facing away from the source of light - the 'dark side of the moon" kind of thing.  Cast shadows are  the kind of shadows that old song "Me and My Shadow" was written about.)

But something happens to form shadows that we should try to understand.

Think about it like this:
You left an orange sitting outside on your patio table. (the raccoons are going to get it, quick, go get it and bring it back in -  but not till we're done using it for an example.)
 The side of the orange facing the sunlight will be warmer in color than it's "native color" - it might be more yellowy-orange than the pure orange, for example. The highlight will also be warm, by the way, and not pure white (which is a cold color.) 
The shadow cast by the orange on the patio table will be influenced by whatever color the table is, but it will be a cooler color than the orange itself. That's because that tabletop is blocked from receiving that warm light because the orange is between it and the sun. So, no warm light, the shadow is cooler.

The shadow side of the orange isn't getting that warm light falling on it, but it does have some air and atmosphere surrounding it. It'll also be cooler.  Maybe that shadow side of the orange will be a dull reddish green instead of bright orange.  Its still a warm color, but it's cooler than the sunny side. (remember that color temperature is relative)

Random tip:  Often you can select the compliment of a color as the basis for a form shadow color.  So, for an orange, I often choose green (the compliment of orange) and a dark earthy red (which is just a darker orange, really) to paint the shadow side.    If you want to understand why that works, ask.  That's a discussion for another day.

So, we have warm light, cool shadows.

BUT.... what if that orange is sitting on, say, a yellow tablecloth.  Ahhh.. now here comes the interesting part. Think of light like an arrow - it can only travel in straight lines.  A shaft of warm sunlight zooms down and hits the yellow tablecloth.  Immediately it bounces back up and hits the shadow side of the orange.  Some of that warm tabletop color is now hitting the shadow side - that's REFLECTED LIGHT

Here, I don't have an orange, but here's  one of my paintings that might demonstrate this.
There are several places where reflected light comes into play here.  See if you can find them, but I'll focus on the white bucket.

Here, the sunlight is coming from above right. A shadow is cast onto the bucket by the  bright orange tarp.  The shadow color is cooler than the tarp. (warm light, cool shadows.)  As the  bucket shape turns away from the sunlight, it starts to fall into shadow, and the color starts getting cooler. You can see its sort of a cool purplish brown. But on the far shadow side of the bucket itself, sitting as it is on the warm colored wood of the boat, we see that warm wood color bouncing back up and changing that cool shadow color to a golden brown.  Even on the inside of the bucket, warm light hits that white interior, warms up, and bounces back to the other side of the bucket to show up as a rich warm tone.

Random Tip #2.  The reflected light will still be a value consistent with the rest of the shadow. Don't be tempted to paint reflected light too light - remember, there are shadow shapes, and light shapes, and don't ever mix them up.

In a situation like the cliff faces in the painting of the Chimney Rocks, the shadow sides of the cliff are SURROUNDED by warm colors of the rocks, hills, earth... sunshine is bouncing all around out there.  Our tendency, (all of us do it, and it is a common mistake for inexperienced artists for sure) is to paint these rock shadows cool. We pull out the blue or the purple or the gray and paint all those little nooks and crannies.  They're in shadow: they should be blue, right?  But, if you've seen paintings with this error, have you ever noticed that they don't portray a real sense of a sunny day?  They seem dead somehow.

Above is one of my early paintings. before I understood much about light.  There are two huge glaring errors (and a bunch of smaller ones) in this painting.  First, I painted all those shadows cool.  Even with a clear sense of the direction of the light and the cast shadows, it still doesn't feel like a bright sunny day. The second error is that there is a clear face in those rocks - once you see it, that's ALL you'll see on this painting. Remember yesterday's post about that - I failed miserably here.  (See I am not proud - this is a bad painting for a whole lot of reasons, but it's a good "how not to paint" example.)

Now, here's a painting by Homer- look at all that beautiful warm reflected light!!! You almost need the sunscreen for this one!! How many of us would want to paint the shadow side of that white horse gray?  But  see how wonderfully this is depicted. Because of the reflected light captured by those luscious warm colors on the horse, we can FEEL that sunshine.Check out the neck of the horse. Where the musculature of his neck slants ever so slightly upward, catching less reflected light and more sky color, it is cooler - same value, but temperature change alone depicts that form.
Oh  it makes me drool!

One more note: reflected light is not always warm. It usually IS warm outside, because the light is generally warm, and nature is filled with warm colors.  But if you had that same orange sitting outside on a  bright blue colored tablecloth, the reflected light will partake of that intense blue color, and will show up on the orange as more of a dull turquoise  (the blue of the tablecloth plus the dark greenish red of the orange itself) Basically, reflected light is the color of the object plus the color of what is being reflected.

I hope this has been helpful. Using reflected light in your paintings can add so much - it will step them up to a higher level if you can understand this, and use it in your work.  

1 comment:

alotter said...

Stunning painting. And very interesting instruction. I am going to save it to read again.