still-photography wrote:
"Shade" is often only lit by blue sky.

So it's more blue.

I would have thought that objects out in the open were lit by the sky and shade was lit by bounced light reflecting off of surrounding objects spilling into those areas not lit by the sun.

still-photography wrote:
"Shade" is often only lit by blue sky.

So it's more blue.

I like this, even though I'm not sure it's right.

How about the sun is more yellow, and therefore direct sunlight is more yellow, whereas the 'shade' is normal ambient light which happens to appear bluer?

(I have no scientific training whatsoever.)

still-photography wrote:
"Shade" is often only lit by blue sky.

So it's more blue.

Truth - shadowed areas as well

still-photography wrote:
"Shade" is often only lit by blue sky.

So it's more blue.

Kent Art Photography wrote:
I like this, even though I'm not sure it's right.

How about the sun is more yellow, and therefore direct sunlight is more yellow, whereas the 'shade' is normal ambient light which happens to appear bluer?

(I have no scientific training whatsoever.)

You are engaging in what is commonly known as chromatic relativism.

Yes, the sun is more yellow than blue. 

If you balance your image so that the sun is neutral, then anything that is lit by the blue sky will be cooler (more blue) and anything lit by green grass (like the underside of a chin) will be more green. Et cetera.

If you balance your image so that "open shade" is neutral, then anything that is lit by a different color of light will by more "that" color.  Again with the et cetera.

Kent Art Photography wrote:
How about the sun is more yellow, and therefore direct sunlight is more yellow, whereas the 'shade' is normal ambient light which happens to appear bluer?

(I have no scientific training whatsoever.)

The corona of the Sun appears yellow -- the disk of the Sun and its emitted light are white.  The atmosphere of the Sun is visible as white and can be seen as such during a solar eclipse.

Sir Isaac Newton's experiment with a prism showed that sunlight was full-spectrum (red-to-violet in the human visible range).  The Sun's electromagnetic output ranges from microwave-through visible light-to-cosmic radiation.

If sunlight were yellow, all we would be able to see would be yellow and black....

.

NothingIsRealButTheGirl wrote:
In the sun things are lit by the sky and sun mainly.

In the shade things are lit by the sky mainly.

Sometimes yes, and sometimes no.

In many places in big cities between buildings virtually no "sky" is illuminating things on the ground, even if the sun is the dominant light source.

In many places in forests with tall trees virtually no "sky" is illuminating things on the ground, even if the sun is the dominant light source.

Et cetera.

NothingIsRealButTheGirl wrote:
In the sun things are lit by the sky and sun mainly.

In the shade things are lit by the sky mainly.

The second and third images in my portfolio, (a before and after), are exemplary of this. There are parts that are lit by direct sun, (more "warm"), and parts that are lit only by the sky, (more blue). They look natural, so I didn't mess with them. Another post said that, "if it looks good, then it IS good", (paraphrased). that is what I go by, (on my "calibrated" monitor). Getting scientific about it doesn't work, because the system, as a whole, seldom follows all of the rules of "proper" color balance.
-Don
EDIT: Of course, there are exceptions, but that is why it has to "look right", above all other principals and procedures. I won't go into light that is reflected off of different surfaces, but it has to be considered when releasing the shutter, or, at least dealt with when post processing an image.

Ruben Vasquez wrote:
So I have a question. I never really thought about it much but daylight has a color temperature (CT) of about 5,000 K but shade typically has a higher CT which often causes the shadows to go blue. Why is that? I know during afternoon hours, light has a relatively short amount of atmosphere to go through so it loses little energy but during sunset and sunrise hours, it has more atmosphere to travel through causing it to lose some energy and shift the CT to the red, orange, and yellow end of the spectrum. But what is it about shade that pushes the CT up higher than open sunlight? I would have thought it would be the other way around or they would have the same CT. Just curious if anyone knows the answer.

Light can be classified as direct or indirect light.

Perfect example of direct light is the sun. The light in this case comes directly from the source.
The spectrum of color of the sun is not a direct result of how much energy is hitting the earth.
The color changes are the result of scattering of light. Many things such as water content, how much atmosphere the light has to travel through has an impact of the color of the source light.

The sky can be considered an indirect source of light.
Check out  Rayleigh scattering on wiki to get the entire reason why the sky the color it is.

"The strong wavelength dependence of the scattering  means that shorter (blue) wavelengths are scattered more strongly than longer (red) wavelengths. This results in the indirect blue light coming from all regions of the sky" (Wiki)

So lets say you put some one if the full shade of a tree. The source light is now the entire region of the sky and what ever else may be reflecting back onto the subject. If you just had the sky as a source the light may be up in the 8000k plus range. If you also had a big yellow building nearby then the color would have a warmer shift.


I am never a big fan of a neutral color balance unless the job calls for color accuracy I generally present my Kelvin temperature, to what I think the specific shot needs then adjusting as I go along. I then do the final adjustments in post.

NothingIsRealButTheGirl wrote:
In the sun things are lit by the sky and sun mainly.

In the shade things are lit by the sky mainly.

still-photography wrote:
Sometimes yes, and sometimes no.

In many places in big cities between buildings virtually no "sky" is illuminating things on the ground, even if the sun is the dominant light source.

In many places in forests with tall trees virtually no "sky" is illuminating things on the ground, even if the sun is the dominant light source.

Et cetera.

I'm glad you agree with me mainly.

MedievalIce wrote:
For a more complete answer: As sunlight enters the atmosphere the light is scattered by particles in the air.  However, not all light is scattered evenly: it depends on the size of the particles and the wavelength of the light.  This is known as Rayleigh scattering.  For smaller particles (on the order of atmospheric molecules) the scattering is proportionate to the wavelength to the -4 power.  Thus shorter wavelengths are scattered much more strongly.  What this means is that bluer wavelengths strike the surface of the earth from a wider variety of angles, while redder wavelengths travel in straighter lines.  In the shade, the physical obstacles block more of the direct red wavelengths coming from the sun than the diffuse blue.  This shifts the ration of red:blue light available creating a bluer look. 

For most practical purposes it is essentially the same thing as thinking that the blue sky lights the areas of shade.

Here we go. This is the kind of answer I was hoping for. Thanks dude. This makes sense to me.

Ruben Vasquez wrote:
Here we go. This is the kind of answer I was hoping for. Thanks dude. This makes sense to me.

That doesn't answer your question. All that explains is why the blue sky is blue, but you don't need to know why the sky is blue in order to know that the shady areas see the blue sky but not the warm sun.

Your question was answered in the first post.

still-photography wrote:
"Shade" is often only lit by blue sky.

So it's more blue.

The cool light reaches places the warm light can't. (and vice versa in the illustration above)

http://gurneyjourney.blogspot.com/2010/ … art-2.html

NothingIsRealButTheGirl wrote:
That doesn't answer your question. All that explains is why the blue sky is blue, but you don't need to know why the sky is blue in order to know that the shady areas see the blue sky but not the warm sun.

Your question was answered in the first post.

The idea that shaded areas are cooler because they're lit by a blue sky, is a very convenient way to think about the situation, and quit honestly how I generally think of it as a first order approximation.  However, this formulation is not technically correct.  First of all the term "sky" is somewhat ambiguous.  There is nothing but an increasingly thin atmosphere and what we call "sky" refers much more to "the stuff we wee when we look up" than to any tangible, measurable object.  Additionally, the sky is certainly not blue.  It is composed of largely transparent gasses, and various conditions interact with light (largely from the sun) to produce different apparent effects from the point of view of the observer.  These can create blue, but also red, pink, yellow, white, black, green, and just about any color.

Thus Rayleigh scattering is often given as the reason for why the sky is blue, but more accurately is is the reason that we perceive the sky to be blue.  It also explains how the blue light travels from the sun (which is where it originates) and ends up in the areas of shade that we photograph.

Again, it's mostly a technicality.

NothingIsRealButTheGirl wrote:
Your question was answered in the first post.

It answered the question but it was so vague and didn't go into any detail. I still didn't make a distinction between the sky and the sun; pretty much considered them one and the same. The other post did go in depth and once I realized that light was scattering to not only make the sky appear blue, but that the sky itself is also a source of light. That's when it clicked and everything made sense.

MedievalIce wrote:

The idea that shaded areas are cooler because they're lit by a blue sky, is a very convenient way to think about the situation, and quit honestly how I generally think of it as a first order approximation.  However, this formulation is not technically correct.  First of all the term "sky" is somewhat ambiguous.  There is nothing but an increasingly thin atmosphere and what we call "sky" refers much more to "the stuff we wee when we look up" than to any tangible, measurable object.  Additionally, the sky is certainly not blue.  It is composed of largely transparent gasses, and various conditions interact with light (largely from the sun) to produce different apparent effects from the point of view of the observer.  These can create blue, but also red, pink, yellow, white, black, green, and just about any color.

Thus Rayleigh scattering is often given as the reason for why the sky is blue, but more accurately is is the reason that we perceive the sky to be blue.  It also explains how the blue light travels from the sun (which is where it originates) and ends up in the areas of shade that we photograph.

Again, it's mostly a technicality.

When the sky is a color other than blue it will fill shadows with a color other than blue.