Friday, November 20, 2009

The Power of Color

A few days ago I waxed poetic about the genius that is Black and White photography. Today I want to go over a little bit about the science of photographing color and how to see the color of light.

In case you didn't know, temperature has a lot to do with making a beautiful color image. For a detailed explanation I suggest you spend some time on Wikipedia. Start with Color Temperature, followed by White Balance, and end with Color Photography. Very educational but possibly a layman's definition might also be helpful? I'll do my best.

Basically the colors we see in the world around us all exist within the visible electromagnetic spectrum. As light enters our atmosphere and comes in contact with gases and other objects, different wavelengths of light (or different colors of light) are absorbed and radiated. Thus trees look green since through the process of photosynthesis plants absorb mainly the shorter wave lengths of light (greens and blues). The sky looks blue because gases and dust in the atmosphere trap and blue wavelengths while allowing others to pass by. And I look a pasty shade of white when outside because in Seattle the sun isn't visible through the dense cloud cover 3/4 of the year. 

The colors in the spectrum vary not only in wavelength and frequency but also in temperature. These are measured in Kelvins. For example incandescent lights tend to vary but are approx. 3000 Kelvins. Daylight (at mid day) is around 5000 K and older florescent lights are closer to 7500K. (Note: Florescent lights today actually come in a variety of different temperatures but most cameras still have a florescent setting that are based on higher Kelvin temperatures.)  Our eyes adjust to these color shifts so we don't often notice the difference, but our cameras do! Here are some samples to show you what I mean.

All three photos were taken with flash, but the cameras color balance has been adjusted to show the shift. Back in the old days you would need to use different kinds of film or a variety of filters, each balanced to to match the temperature of the available light. This was difficult for those of us shooting events or on location in all different situations. With digital, it's easy to adjust the color balance and achieve the correct color. OR you can use the shift to your advantage and shoot using the "wrong" settings and mimic the look of cross processing. This is a style that was very popular in the 1990's print media and film. It's done by processing slide film in chemicals designed for negative film (C-41) or negatives film in slide film chemicals(E-6).  Here is a tutorial of how to get this same look with a digital file with photoshop. Below is the same photo as above "cross processed"  and the original. Which is your favorite?

The color shifts towards the red and yellow while contrast is enhanced. A lot of times this same style would be done with purposefull over exposures by between 2-6 stops, thus blowing out the highlights and exaggerating the look of the cross processing. I'd love to see your examples of the same kind of style. Feel free to post images and links here. To view more of my work please visit Irene Jones Photography Online.
Tomorrow blog: Top ten photography blogs to follow (In my opinion.)

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