Black and white photography was the first form of photography to be invented over 150 years ago, and has remained popular since then for its aesthetic and artistic properties. Traditional black and white photography is more or less is the result of monochromatic, light-sensitive chemicals on some sort of medium such as film or plates. Some chemicals respond to different colors of light more than others. A combination of light color and film selection with black and white photography produce different effects when the colors are represented in monochrome. That is, if a film that was hypersensitive to red, it would have bright white areas if the light source was originally red. Traditionally, photographers had to choose a type of black and white film to whatever effect he or she was going for, and if he or she had control over lighting, would adjust lighting according to the film. Some photographers still prefer this method because of the limitation of digital cameras
When using a digital camera, a photographer obviously does not have the option to choose a type of film for a desired effect. Most cameras only have one sensor, so this requires that either the camera convert to image to a monochrome image, or the photographer convert in in post-processing. Some cameras have options when converting images to black and white, but for the most control, shooting and saving an image in a RAW format gives the photographer the maximum number of options when post-processing.
When I first started playing with black and white digital photography, I would typically just desaturate (that is to convert to black and white using a saturation control) an image after downloading off the camera. I then started tweaking setting such then even though the image looked odd while in color, it produced some nice effect after desaturating. With post processing, you can simulate the effects of many vintage films. The trick here is finding the right color mix– that is the intensity of colors in relation to one another before one desaturates the image. Here are some of the things I play with when black and whites in no particular order:
1.) Adjust Temperature — Cool temperatures will exaggerate blues and indigos while warm temperatures will exaggerate reds and oranges. Night shots, at least in my experience tend to be warm when looking at them on the camera. Making them cooler can make the colors more natural, thereby making the back and white photo look more natural. If you want really punchy night photos, increase the temperature!
2.) Adjust the Tint — Usually, this is a function between greens and violets, as they are complementary colors. These will obviously exaggerate the respective extremes.
3.) Adjust the Luminance (or color mix) per color channels. This can change one color from appearing as dark to appearing as light in a black and white photo.
4.) Adjust Brightness and Contrast, localized and universally. Localized contrast means manipulating the images tone curve directly by making certain tones or lighter and while universally means adjusting the entire images. Flatter (that is less contrast) are typically more conducive for portraits, but occasionally stark contrast is fun.
Here are some examples: