Take a look at the two interpretations of the following photo, taken at Oregon's Painted Hills in the John Day National Monument. Which one is the more dramatic?
To most of us, the black and white image has more drama. The absence of color directs your eye to the structure of the tree, which was what led me to take the photo. The greater contrast between light and dark portions of the b&w version capture the attention, direct the eye along the lines, and make the clouds seem foreboding. This is a good example of why I so often turn color images into black and white interpretations.
Digital capture gives us great tools for working in black and white. Before digital, we had to select specific films for different types of shooting situations and then mount color filters to properly render certain subjects -- red for dramatic skies, orange for portraits, green for vegetation, etc. But if you failed to properly assess how those filters would interpret a scene, you were in trouble, stuck with a black sky against white foliage or a head of red hair that turned out flat as you filtered for freckles.
With digital photography, you select ISO to match the situation and introduce grain and adjust contrast in the editing process. Best of all, the color filters are in the color image. Because you capture all the color information in the red, green, and blue channels, you can adjust them to your heart's content to create just the mood you want.
In Lightroom, I begin by adjusting exposure, highlights, shadows, contrast, etc. to the original image in the Develop module. When satisfied that I have the best color image possible, I create a virtual copy by pressing Command/Control-' (the single quote key). This allows me to leave the original intact while I process a copy as a black and white image. Converting to monochrome is as simple as pressing "V" on the keyboard, but the resulting version usually represents a compromise.
I turn to the color sliders in the black and white dialogue in the HSL/Color/B&W panel. As shown below, the eight sliders allow you to adjust not just the red, green and blue channels, but combinations that represent mixtures of the three. The settings show the work I've done to separate a magenta flower from the red rocks of Sedona.
The same filtering principles used during the days of negative film apply here, but you don't have to know them. You can play with the eight sliders until you get the look you want, even making new virtual copies to create additional interpretations. If you like a particular look, you can save it as a Lightroom preset so that you can apply the recipe to similar images with one click.
When satisfied with the results, I return to the exposure panel and make overall tweaks to the exposure and contrast before a final sharpening. Now I can print the photo or upload to my website.
There are several third-party plug-ins that offer one even greater control, including Nik Silver Effects, Topaz Labs B&W Effects, and OnOne Perfect Photo Suite, soon to become simply OnOne Photo. In future posts, I'll take a look at some of them. For now, find an image whose structure suggests it might be a good candidate for a monochrome interpretation and play with it.