Everything Looks Better in Black & White
One of the easiest and simplest ways to create a black and white image from a color image file is to use Photoshop’s Desaturate (Image > Adjustments > Desaturate) or just use the Monochrome command found in some image editing programs, usually under the Mode menu. In Photoshop the that command can be found under Image > Mode > Grayscale) and it basically does the same thing as Desaturate; it simply takes away all of the color.
The Desaturate command converts a color image to grayscale values and assigns equal red, green, and blue values to each pixel to what remains an RGB image. The lightness value of each pixel does not change. This command has the same effect as setting Saturation to minus 100 in the Hue/Saturation dialog box. (Image > Adjustments > Hue/Saturation) Grayscale mode uses different shades of gray in an image and Photoshop discards all of the color information that’s in the original image. The gray levels of the converted pixels represent the luminosity of the original pixels.
Both of these methods produce a photograph that lacks color but it also usually also lacks any impact. The images produced this way just don’t look like the textbook definition of a “black and white” photograph. What you need is to take that flat looking image and add some drama with the following steps. This image of a classic Dodge truck was captured as a color file using a Leica Digilux 2 with a manual mode exposure of 1/2000 sec at f/2 and ISO 200.
When you select Image > Mode > Grayscale in Photoshop, a small dialog box appears asking if it’s OK to discard the color information. Since you should be working with a copy of the file anyway and your original is safely ensconced on a CD/DVD tucked away somewhere safe, it’s OK to click OK and remove the color but that’s all that will happen.
The resulting monochrome file will usually be flat and lacking the contrast of the original color image file, so the simplest way to correct this is to use the Brightness/Contrast control (Image > Adjustments > Brightness/Contrast) to kick up the contrast a bit by gradually moving the sliders increasing contrast and brightness by observing the effect before clicking OK.
An alternative is to use or use the Levels command (Image > Adjustments > Levels) to create an S-shaped curve that produces a more film like look. The screen shots is what I actually applied to the finished image but there are no magic numbers here because the shape of the curve depends on the original tones of your photograph. The finished image was produced with only two image tweaks: the first to remove all color and the second to increase contrast slightly. It may be all you need or want to do but if you want to try something different, keep reading this blog on SFX Mondays.