Wednesday, August 21, 2013

Colors

                       
 Color is a great cinematographic tool. 

 All human emotions, moods and cultural symbols are connected to specific colors. 

Colors make spaces personal, and convert mundane situations to magical. What are these colors?


                              








It is very interesting to note that colors exist only in our minds. 

It is necessary to know how one sees, before one tries to grasp the complex phenomenon of color image.

Human eyes are light receptors. When a light source (such as, the sun, or a candle) emits light, that light travels in a straight line through the space. 

If our eyes are on that straight line, certain areas in them get excited. That behavior is like a pool of water creating ripples when a stone is thrown. 

It is easy to visualize light consisting of small stones (ie, energy packets), and the eyes of chemicals. When light hits the chemicals, depending on the force and the speed of the stones the chemicals create different types of ripples.




      

Photo-receptors in the human eye: diagrammatic representation 


Light particles strangely behave like waves themselves when they just travel in empty space, not hitting anything in the path. 

The ripples created by light in the human eye are related to the waves associated to the light themselves.

Similar to any other uniformly moving wave, light waves are named by two basic characteristic features – wavelength and amplitude.


Just like the water waves, light waves have upper maximum energy points (peaks), lower maximum energy points (troughs) and point of no energy (zero crossings.)

The distance between two peaks (or two troughs, or two zero crossing points) shows the way a light looks. 

As that distance changes, the ripples created in the eyes also change. That changes the color in effect.



Color, very significantly, has no relation to how high the peak is (or how low the trough.) 

The sensation of color is the distance between any two peaks, as already stated. This distance is technically known as the wavelength of the light wave.

However, besides color, light is also known by how bright or dim it is. 

Height of the peak (or, the trough) starting from the zero crossing point determines the sensation of brightness. 

The higher the peak, the brighter is the light (regardless of its color.) This height is technically known as amplitude of the light wave.

Hence, color and brightness are two unrelated elements of light. One can be changed without changing the other.

All these light waves, mixed in some proportion, look white or gray. 

In turn, when white light is passed through a dispersion medium (such as, a prism) that separates the elemental wavelengths of white light, different colors can be seen as color bands.

 A range of such color bands is called spectrum.



However, as can be seen in the image above, only certain wavelengths can cause sensation in the human eye. 

Like any other distance, wavelengths are measured in meter (or fraction of a meter, nanometer in this case.)

Beyond these wavelengths, both on the longer and the shorter sides, waves cannot be seen. These are invisible waves that we use for purposes other than seeing.


Coming back to colors, it is not surprising to know that some people cannot see a few colors, some have problems in separating one color from another and some do not see any color at all. 

After all color is a human sensation. 

Depending on some minor defects in the human eye or in the brain, light waves may cause sensations different from the standard.

Colors are created in the human mind. 

 So, they build up a major part of our reality. Enhancing moods, creating very interesting contrasts, used symbolically for statement or comment, colors are the building blocks of any visual expression next in importance only to the tonal contrast.

Before taking a journey in the symbolic meaning of colors, it is necessary to know how color is reproduced in traditional motion picture photography, the traditional videography and the modern age digital images. 

Only the basics can be discussed in this article.

World's first color photograph was printed as far back as in the 1850s. The modern color printing method, however, was officially first tried in 1861.


It was made by a simple process of mixing three monochrome channel information – the red, the green and the blue images.

The three basic building blocks for any color light were well known for many years. 

One can get any color of light, by mixing light of colors red, green and blue in different proportions. 

Mixing any two or all the three in different brightness of each yield all the other colors human eyes can perceive.

Black and white photography was created on the basis of Silver bromide's quality of undergoing chemical reaction as light falls on it.

A plastic strip coated with silver bromide particles is exposed at the camera gate. Variation of exposure across the frame is recorded as variation of chemical reaction in the corresponding areas.

 Simply put, that means bright objects reflect more light to that part of the frame and more chemicals undergo reaction there.

When such an exposed filmstrip is washed with mild alkaline solution (known as developer), bromine is washed out, and metallic silver comes out to make an image according to the tonal contrast across the frame. 

That metallic silver looks black (unlike the normal metallic silver's white appearance.)

The brighter an object is in a photographic frame, its corresponding image area undergoes more chemical reaction. 

More reaction leads to darker image area (ie, more metallic silver) after development
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As brighter, whiter, objects are represented as darker areas in such an image, it is called negative.

A negative can be copied by transmitting light through it to a similar photographic filmstrip.

Negative of a negative yields a positive, where white looks white in the image.

However, such an image is black and white, with shades of grays in between. It is not color!

However, the same image can be taken thrice putting a different color filter on the camera lens each time – the three primary colors – red, green and blue. 

There will be three different grayscale images, but each of them will be different from the others in tonal variation.

If these images are overlapped on one another at that time of printing, the resulting image is color!

Reproducing color this way is known as the additive color image reproduction.

Later, films took a different route to reproducing color in a cheaper way – the subtractive method similar to what painters had used for ages in their paintings.

 But, modern digital images follow the same additive route.



In a modern digital camera, just like the human eye, there are three types of wave receptors – one each for Red, green and blue light.


                            
Working together, they create all different colors.

In different cultures, same color has different symbolic meanings and psychological associations.

Movies are built up on color coding and mythic symbolism.

However, a lot in the storytelling is based on the universal reaction to color.

Warm colors between 600 and 700 nm wavelengths mean life, excitement, activity.




Cool colors, on the other hand, evoke lethargy, sleep, serenity, lack of activity and sex.




 It takes the whole team of screenplay writer, director, production designer and cinematographer to harp on the emotion of the story, and to see how the plot extracts that emotion from the audio-visual imagery.

That is called imagination. Colors play a big role in that.









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