Today’s Question: Is there a “best” way to apply a color tint to a black and white photo, or does it not really matter which method you use?
Tim’s Quick Answer: For a basic tint consisting of a single color, I would say any of the various options available would produce about the same result, all other things being equal. However, there are several options that allow you to exercise greater control and produce more interesting results, such as split toning or a gradient map.
More Detail: The way I generally describe a color tint for a black and white image is that you are replacing the shades of gray in the image with shades of a specific color. For example, a sepia effect involves replacing the shades of gray in a black and white photo with shades of a brownish-yellow color.
For this relatively simple effect, there isn’t a significant difference in terms of the final result (all other things being equal) among the various ways you could add such a color tint. Lightroom and Photoshop, for example, provide several options for adding a color tint to a black and white image, including the Tint control available with the Black & White adjustment and the Colorize option available with the Hue/Saturation adjustment (both of these specific examples being found in Photoshop).
For a slightly more sophisticated effect, you can use a Split Toning adjustment, which can be found in Adobe Camera Raw and Lightroom, among other software tools. With split toning you are adding a color tint similar to what you might use to create a sepia effect, with the difference being that you are able to apply two different colors. So, for example, you could create an effect where shadow areas are a bit more blue and highlight areas are a bit more yellow, rather than having the entire image appear with the same color tint.
If you really want to exercise significant control over this type of color tint that involves more than a single color, the Gradient Map in Photoshop is the option I recommend. You can start, for example, with a simple black-to-white gradient for the Gradient Map adjustment layer. You can then add additional color stops to define the gradient.
A very simple gradient for the Gradient Map adjustment might include black and white at the extremes, with a single additional color stop for sepia, resulting in a basic sepia-tone effect. You could include two color stops between black and white to produce the effect of a Split Toning adjustment. But you can add even more color stops to produce a very sophisticated tint effect for what would otherwise be a black and white image, with the Gradient Map assigning overall color and tonal values based on the luminance values of each pixel within the photo.
So, again, in terms of the basic result, you can feel perfectly comfortable choosing among any of the available adjustment options in Photoshop, Lightroom, or other software tools that allow you to apply a color tint to a black and white (or even color) photo. However, the various tools available for applying the color tint in the first place provide the potential to exercise greater control over the image. It is also worth noting that while it is perhaps most common to add a color tint to an image that is being interpreted as a black and white image, you can also add a color tint or split toning effect to a full-color photo, without removing the original color.