Black and White in Photoshop I - Black and White in Photoshop CS4 and Photoshop Lightroom - page 127

Original Color Image

Foundation & Theory: Color Filters and Black and
White Film

Since photography began in black and white, it is impossible to truly
understand any of its newer forms without at least a passing knowledge of its
beginning. Traditional black and white photographers have always needed to
be attentive to the type and distribution of color within their images. Just as
with color photography, black and white photography can use the spectral
relationships between colors and tonality to make a subject stand out.
In order to maximize this principle, black and white photographers
traditionally used color i lters to manipulate how the spectral relationship
between colors was translated into black and white. Colored i lters such as
blue, red, yellow and orange were used to selectively af ect the gradient and
contrast in the tonality of colors as they recorded onto i lm. By allowing colors
that are similar to their own color to pass through and expose onto the i lm,
while simultaneously blocking colors that are of opposite wavelengths to the
i lter color, colors were ef ectively lightened and darkened as they recorded
on the i lm. Therefore, a strong red i lter will lighten reds and darken blues, a
green i lter will lighten greens and darken reds, etc. For example, landscape

Red Filter

Orange Filter

Blue Filter