We recently published an article on shooting in black and white, but that was really a beginners primer to black and white. To achieve truly great black and white shots, there’s one more step you need to do in post production to add polish.contrast in a color image, not all colors are equally luminous, and luminosity is all that matters in black and white images. To illustrate this, consider the image to the left. It has four colors: red, green, blue, and yellow. Pretty high contrast right? What you may not be able to tell from just looking at it, is all the colors shown have the exact same saturation level.
The same thing happens to your video when all you do is drop the saturation to achieve black and white. All pixels of equal saturation values end up with the same luminosity. The result is a very flat, bland shot.
To combat this, we simply need to adjust the luminosity of each color before we apply the black and white effect. Don’t worry. It’s easier than it sounds.video editing applications apply effects in an ordered fashion. In this case, we simply need to apply a color balance effect followed by a black and white or hue/saturation effect (HSL). When looking at your list of applied effects, just make sure Color Balance is sitting above your Black and White effect. Even though we’re now looking at a black and white image in the viewer, we will see changes as we adjust Color Balance. In some programs, like After Effects, the Black and White tool itself has color balance sliders. The same is true for Photoshop if you’re only working on a still image.
That’s all it really takes. Play with the intensity of each color slider in the color balance tool and observe how your black and white image reacts. Eventually you will have an image with contrasting shades of grey exactly where you need them to be without simply relying on global contrast adjustments like curves, levels, or brightness/contrast.