Black and White Photo Conversion
Copyright 2006 Peter Horner
Most images were produced in black and white for nearly a
hundred years after the invention of photography, but now colour
images have become commonplace. Creating strong three
dimensional images on a piece of paper is one of the best
attributes of black and white photography, as the effect can be
more striking than with a colour photograph. Without the colour
to distract us we become more aware of the subtle tones which
can be found within a black and white image. In this article I
will share the technique I use that will help you create
beautiful, striking and moody black and white images from your
colour photographs.
Digital cameras have a black and white mode but more information
and detail will be recorded in colour, which will also create a
higher quality printed image. This is why I always shoot in
colour then convert images later. There are several ways of
converting an image to black and white using Photoshop and many
other image editing programs. You could simply desaturate the
colours, but creating a black and white image with real tone and
definition goes beyond this. Levels, curves and the Unsharp Mask
can be used creatively with black and white conversion to
provide further control over tones and contrast to create a
stunning image.
Channel Mixer - I have found that using the Photoshop Channel
Mixer is the easiest way to convert an image to black and white
and produces the best results. The Channel Mixer allows you to
control how much red, green and blue contribute to the final
monochrome image.
The Channel Mixer can be selected from the adjustment layer
popup menu in the layers palette or you can also access it from
under the image menu.
Clicking on the left tick box entitled Monochrome will convert
your photograph into a greyscale image, and gives you the
ability to blend the red, green and blue channels. Adjust each
of the sliders to produce an image to your liking. As a rule
make sure that the total values for each channel adds up to
100%. This creates monochrome images that are the equivalent of
ones shot on black and white film through red, green or blue
filters. For example if you wanted to maximize cloud contrast in
a blue sky, then a red filter would achieve this. I usually set
the red channel to 0 and the green channel to 100 to cut down on
the amount of noise, or sometimes a combination of red and green
depending on the image.
Curves
and Levels - Brightness and contrast can be adjusted in
Photoshop by using the curves and levels tools, which can be
found under Image > Adjustments Curves/Levels. Both curves and
levels allow you to adjust the tonal range of an image. When
using the levels command you can make adjustments to just three
variables, highlights, shadows and midtones. I prefer to use
curves as it gives you more precision. With curves you can
adjust any point along a scale while keeping up to 15 other
values constant. By adjusting the black point and white point in
curves you can give your image more contrast. At opposite ends
of the diagonal line you will find a small dot. When you grab
hold one of the dots with your mouse and drag it around you will
see the image change. To create more contrast drag the black
point lower and the white point higher, so that either end of
the diagonal line is curved. Practice using curves and levels
and explore the different effects you can achieve with your
images.
Unsharp Mask - The Unsharp Mask is my preferred tool for
sharpening images, which can be found under Filter > Sharpen >
Unsharp Mask. It is a traditional film compositing technique
used to sharpen edges in an image and corrects blurring. The
Unsharp Mask locates pixels that differ from surrounding pixels
by the threshold you specify and increases the pixels' contrast
by the amount you specify. In order to get the look which I
desire in my images I use the Unsharp Mask twice. I begin by
using a high radius and lower amount, such as a radius of 50
pixels and an amount of 30%. This gives the image a much more
intense look and details will stand out. The second time I use a
lower radius of 1 pixel with a higher amount of 30%, which will
correct any blurring and sharpen the image.
Visit this page to view examples of images created using a
combination of these techniques -
http://www.designerprint.co.uk/articles/black-and-white-photograp
hy-conversion.htm
About the author:
Peter Horner has years of experience in photography and digital
printing technologies and also co-created the large format
printing company DesignerPrint. Using large format printing
technology DesignerPrint create canvas prints, block mounts, and
poster prints.
http://www.designerprint.co.uk/services/canvas.htm
Written by: Peter Horner
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