Black and white photos often add more drama or dynamics to a photo. Rather than focusing on the colors within a shot, the contrast and details dominate a photo. This usually changes the way the audience’s eyes scan an image, drawing their attention to different places on the image than a color one. One word of caution, though, is not to take your photos in black and white. I’ll explain why having a color option is a safe backup and how editing the color channels to turn a photo black and white gives you much more control over the final image.
Shooting photos in color gives you many options, whereas shooting in black and white leaves you with what you have. A color photo has more data to manipulate in order to create the image your imagination sees. Perhaps some color remains, others become muted, others saturated. What if the photo looks better in color or with some color than in complete black and white? More importantly, though, there is simply more information to create the perfect image by shooting it in color, then converting it to black and white and manipulating the color channels.
If you are using a powerful photo editing application, you will see color channel sliders in the black and white section. How this is presented will vary between applications, however. Generally, a check box exists to turn the photo black and white and the sliders for color channels are visible next to the check box somewhere. Before I dive in deeper into the process, let me explain what these color channels are for.
In a color photo, these color channels increase or decrease the amount of color in that channel. Increasing red, for example, adds more red to the photo and saturates the existing red tones. Decreasing red removes red from the image. The same concept applies throughout each color channel available. By adjusting these in a color photo, you can color correct the photo, though other tools generally exist for this purpose, or you can add color tones to the image. Your imagination is really your limit.
In the context of color channels in black and white, we’re more interested in the contrast and brightness the channels provide. By being familiar with the colors that existed in the image, we can make an educated guess as to how the channels will affect our black and white image. If we have a photo with a lot of blue areas in it, decreasing the blue channel will darken the areas of the image that were blue. Increasing blue will brighten the blue areas of the image. Generally the red channel affects skin tones, sometimes yellow as well. If we want to be sure the skin tones stand out, be sure to play with those channels.
So what happens when you take a photo in black and white to begin with on a digital camera? Generally, only the red channel is captured and saved in black and white, ignoring all of the other color channels. Some cameras may use an intelligent combination or an equal amount of each channel, but either way, it’s a preset and limits your creative options.
If you want to get the most out of these options, I would advise shooting in RAW as well. While RAW photos are significantly larger in file size than jpeg and can’t be shared as easily, RAW photos preserve much more data in the photo. When editing a RAW file, you can recover highlights and shadows much more cleanly than you could from a jpeg. RAW photos give you better control over exposure in editing as well. More importantly, more color information is preserved, giving you even greater detail and control over how the color channels manipulate the image.