Monday, January 17, 2011

Vertical Planes in Shadow

Here’s an illustration of the point, “On a sunny day, vertical surfaces in shadow usually receive two strong sources of illumination: warm ground light and blue sky light.”

The shadow side of this pile of snow is distinctly blue on the top surface. The horizontal plane of the of cast shadow at right is also very blue from the sky above. But the vertical surface in shadow is receiving a combination of that blue skylight and a warmer light reflected from the illuminated surfaces of snow on the ground.

Reflected light influences not just shadowed surfaces, but also illuminated surfaces. Just to the left of the base of the pile, the snow on the ground becomes very light where the reflected light is added to the direct illumination from the sun.

Color and Light, page 67.


Mario said...

It's astonishing that the warmer light in the shadow is still quite cold (possibly a slighlty greenish blue), as I have verified with the color picker (eyedropper); but it looks much warmer because of the color around.

Christian Schlierkamp said...

That reminds me of a blog entry of illustrator Petar Meseldzija ("the legend of steel bashaw", mentioned here before) on Rembrandt van Rijn's mastery and his "glowing shadows":

“Although Rembrandt is often praised because of his juicy, thick impasto, expressively painted light parts, Rembrandt’s power, in fact, lies in his shadows!”
I think Rembrandt must have deeply internalised this very principle and mastered it like no other to achieve his translucent glowing shadows.

Unknown said...

Oh! This reminds me! I got your book for Christmas! I am embarrassed to admit that I've been too distracted by family matters and getting my house ready for selling to open it. Well, except to examine all the images. Gorgeous paintings in there!

Thanks for pointing out the light (and color) in this photo. I can't wait to dig into your book.

Also, as an American woman, I pledge to participate in BAW's boycott. He is so totally right! From now on, I, too, will boycott American women! You have convinced me! From this point forward I will only purchase my women from strong Brazilian stock.

I must inform my husband of my plans. This is important information that must be shared!

Unknown said...

All those subtleties of shadows.
They are not easily caught with a camera.

billspaintingmn said...

Very keen obsevation Mr. Gurney!
I have been observing winter scenes
and look for the subtle differences.
How you analize them is helpful indeed!
I also have both books and will be studying them.

Don't sterotype women! My wife was an American women and didn't fit your "American woman" profile one bit!
You come off as a scorned partner unable to accept half the problem!
(...Oops! Did I say that?) Sorry dude, I guess opinions are opinions

Unknown said...

I noticed this about snow. Thanks for clearing it up. I always found snow hard to shade.

Oh yeah, boycott American women my foot. My uncle is married to a foreigner and she's a JERK.
...And what the heck does this have to do with snow? Stupid spammers. Just goes to show what kind of guy he is.

James Gurney said...

Whoops! Jeanette here, doing some blog-cleaning for husband Jim, and I deleted the spam about "boycotting American women", which was completely off topic. Didn't realize that you were all riffing off it!

jeff jordan said...

My partner Nancy is an AWESOME American woman, and she doesn't wear Reeboks.........