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Old Jul 11, 2010, 3:56 PM   #1
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Default Test your color knowledge

Test your color knowledge

1. Everybody knows what color a ripe watermelon is when you slice it open. Its red right?
But, what color is it inside before you cut it open? ... Does it change?

2. Did you know that you can mix red, blue and green together and get white? Could that be possible?

3. Is Black a color?
4. Is white a color?

Don't answer yet. By the time you finish reading this you may change your mind.

There are two different methods of creating color; additive and subtractive.
From early childhood we learn the three primary colors: Red, yellow and blue.
Take a little red and a little yellow, mix... and you have orange. Blue and yellow, green. and so on. By mixing different amounts of the three various primary colors you can make literally millions of different colors. Well, you do have to use white and black to create the different shades.

How do you make black? That's easy, you mix all the primary colors together and wah la! You have black. Well, sort of. It reflects so little light that it appears black.
If you are familiar with printing, you may have heard the term “four color process” printing. I can print the equivalent of a full color photograph by using only four colors. The three primary colors and black. If mixing all three colors together make black, why do I need to use an additional black ink? Because inks are somewhat translucent, it allows the overlapping colors to be seen through each other. In other words if you printed a patch of yellow and then printed a patch of blue half way on top of it you would have both a patch of yellow and blue with a patch of green where they over lap. If you add a spot of red on top of the green, it would appear some what black but, not a true black. That's why they use a special pigment to create a true black called Process black. The same is true for white. Although most of the time printers rely on the white of the paper they are printing on to achieve the shade of color they're seeking, there is a true solid white used for special purposes and a “Mixing white” used to mix inks when you need to lighten the shade of ink to achieve the color needed when doing spot color work. This mixing white isn't really white, it looks more bacon fat in the bottom of the fry pan after it has cooled.
To sum it up, what you need for full color printing is: Process black, Process blue (called cyan) Process red (called magenta) and Process yellow (called process yellow). This is called the additive method. Works basically the same as mixing paint.



The subtractive method is quite different, the 3 primary colors are Red, Green and Blue or RGB. It uses beams of light to create the full spectrum of colors. I know less about how this method work, which is a shame because that's what we deal with in photography.
In the color chart below you can see for example, if you mix the red beam and the green beam of light, you get a yellow! That's why they call it “subtractive” it removes a certain spectrum of light to allow another spectrum to pass.
As you can see in the chart, when all three color guns merge into one spot, you have white.




Here are a few samples of images made with additive color mixing.
Magnified many times over. this is a 200% crop from a macro shot. Here you can't begin to tell what it is.





Here is a 100% crop.


OK, now you might start to see that these are a bunch of wires inside a computer... No?


How bout now?


Here is the full frame shot @ 190mm no flash from about 4 ft away. Note the red circle around the group of wires in the computer. this shot was taken from the back of a PC magazine shoeing about 1/4 of the page.


This is an example of four color process printing. The image you see here is called a half tone. it started out as a photograph run through a computer to get what they call "color separations" and the separations are out putted to either film or, in direct to plate format that are then put on a printing press and reproduced.

Here is one more taken from the same mag.



No ideas yet? here's a hint, think Microsoft Advertisement.



See the red circle in the middle? The two photos above were taken with the DA55-300 + Raynox 250.

Whats really funny if you stop and think about it, the image above started out as an RGB subtractive color image. Then went through a change and was converted to CMYK Additive color image for printing. Then I took a photo of it and turned it into an RGB image of a CMYK image so, what is it now?

BTW, the answer to the first question is, Black. before you cut open a watermelon there is no light inside, since color is the reflection of light and there is no light inside a melon. there fore it would be black.
#2. is true. see color chart above.
#3. Black is not a color. see answer #1.
#4. Yes. see answer #2.

Well, I tried to make this interesting without getting too technical. I hope it inspires some of you to explore further our wonderful world of color!
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Old Jul 12, 2010, 9:19 AM   #2
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GW, the only way I'll believe the watermelon story is if I see your shot from inside the watermelon. LOL

Kidding aside it's a nice tutorial on color, thanks for sharing.
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Old Jul 12, 2010, 12:46 PM   #3
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That was a really interesting read GW - thanks for posting.
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Old Jul 12, 2010, 12:48 PM   #4
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I've always been curious about the colour of the inside of my fridge too. I'm ok now. Thanks..
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Old Jul 12, 2010, 2:13 PM   #5
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Thanks for commenting Lou.
I'm guessing, due to lack of comment most must have found it either un-interesting or were totally stunned into speechlessness!


As for the watermelon, My arthroscopic surgeon says the inside of a watermelon looks surprisingly like my gallbladder before he took it out.
Here is a photo of that.



proof positive
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Old Jul 12, 2010, 2:21 PM   #6
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Thanks Kevin, glad you like it.

Frank, see
above photo, its pretty much the same as your fridge.
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Old Jul 12, 2010, 5:34 PM   #7
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Quote:
Originally Posted by Goldwinger View Post
Thanks Kevin, glad you like it.

Frank, see
above photo, its pretty much the same as your fridge.
Thanks for the help.
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Old Jul 13, 2010, 5:45 PM   #8
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You guys are major loonies to get into this at this level. It was, however, very interesting.
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Old Jul 13, 2010, 8:31 PM   #9
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Quote:
Originally Posted by pboerger View Post
You guys are major loonies to get into this at this level. It was, however, very interesting.

Thanks pboerger, I'll take that as a compliment!
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Old Jul 14, 2010, 6:40 AM   #10
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put me down as totally stunned
i work in the digital printing industry and have to work with this everyday
and still trying to figure it out lol

but it now begs the question
what colour is a green parrot
seriously
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