Photoshop Elements >
Color Correction >
Measure Color
You'll need to measure the color of a photograph, especially
when correcting skin tones.
Here are several ways to measure a color on your photograph.
1) Make sure the Background copy layer is active (highlighted).
2) Select the Eyedropper tool.
3) In the options bar, set to Sample Size to 5 by 5 Average.
Now, you're averaging the color of 5 pixels by 5 pixels,
or 25 pixels total.
4) Open the Info panel in the panel bin, or go to Windows >
Info.
5) Move the Eyedropper cursor around the photograph.
The red (R), green (G), and blue (B) values change in the Info panel.
6) If you click, the color appears as the foreground color.
Color Cast Determination
To determine the color of a color cast:
• Find an area on the photograph that should be gray.
If there's a color cast, this should-be gray area will be
tinted with the color cast.
The should-be gray area must be located in the same light as
the subject of the photograph.
You can also:
• Find an area that's white with detail.
Detail means the white area isn't overexposed.
For example, let's say you have a photograph taken in a loft.
The foreground, where a friend is sitting on a sofa, is too orange
from the track lighting.
Your friend is orange because you forgot to switch your white
balance to the tungsten setting (light bulb icon).
You have too choices of areas to measure the color:
1) He's wearing a white shirt.
The shirt is overexposed on the shoulders, but has some texture
in front.
The RGB values of the overexposed area will be 255 in the
Info panel.
2) In the dimly lighted background, there's a gray chair.
Don't measure the color on the gray chair.
It's not in the same light as your friend.
Don't measure the color on the overexposed portions of your
friend's white shirt.
Do measure the color on the front of the shirt, where there's
derail.
Skin Tone Correction
For a skin tone correction, place the Eyedropper cursor on a
representative location on the subject's face, often on the
forehead.
Make sure the area is:
• Without glare.
• Not in a shadow.
• An unblemished area.
• Without makeup other than a foundation, such as rouge on a
cheek.
• Not being illuminated by light bouncing off of a colored hat
or colorful clothing.
4) As you move the Eyedropper cursor around, the RGB values change in the Info panel.
Don't inadvertently click the mouse when using the Eyedropper
tool.
The foreground color will change if you do so.
In the above photograph, the subject's forehead has the following
color values:
R: 225
G: 187
B: 167
Find them in the Info panel below.
Color Measured on Forehead
These RGB values are probably meaningless for color
correction.
At first, it's hard to look at a skin tone, and be able to
judge the color.
If you place the Eyedropper cursor on a neutral area in the photograph,
the color cast will be more evident.
There's no optimum gray or white area in this photograph.
In the above photograph, the color in the lower-left corner was
measured:
R: 212
G: 216
B: 227
Find them in the Info panel below.
Color Measured on Lower-left Corner
The value for blue is ten to thirteen point higher than the values
for the other two colors.
If the photograph had a neutral color balance, no color cast,
then the values for the colors would be similar.
But, the blue value is high.
A high blue means the yellow is low.
Yellow needs to be added.
Gray Card & the
GretagMacBeth ColorChecker
Gray Card
If you're going to photograph someone, you could have the
person hold up a gray card, for the first photograph.
Then, when need to measure the color to see if there's a
color cast, you have a guaranteed should-be gray area in one
of the photographs.
Make sure the card is in the same light as the subject, and if
the lighting changes, photograph the gray card again.
Purchase a durable gray card, not some flimsy house brand.
Kodak R-27 Gray Cards
GretagMacBeth ColorChecker
You can include a GretagMacBeth ColorChecker card in one
of the photographs.
The card has a range of tones from white to black, and a range
of colors.
Later, when you're at your computer, you can use the photograph
with the card to set the black, gray, and white, points.
You won't have to figure out where to click a photograph.
Just click three times on the appropriate squares on the card.
When photographing the card, make sure it's in the same light
as the subject, and if the lighting changes, photograph the card
again.
Don't confuse the GretagMacBeth ColorChecker with the GretagMacBeth
ColorChecker SG, which is $280.
GretagMacBeth ColorChecker
Photoshop has some additional color measurement features.
Color Sample
With the Eyedropper tool, you can click multiple locations on
a photograph, and the values of each sample appear and remain on
the Info panel.
Selective Color
You can adjust yellow, magenta, and cyan, by percentage increases
and decreases.
By changing the colors by a percentage, you can more easily apply
the same correction to other photographs.
Go to Image > Adjust > Selective Color.
• For more about choosing colors, go to
Color
Picking.
• The
Curvemeister program has a distinctive way of depicting color
called the
Hue Clock.
The position of the clock hand, and length of the hand, shows
the color.
Curvemeister
