Styles come and go in everything, even photography. The latest style for black and white seems to be a very high contrast model. The method I want to demonstrate harkens back to a different time, a time when total tonality was king. No I don’t want to live in the past and even though giving an image a wide tonal range might take its cues from the past, it also allows you to use tonality for artistic purpose.
In the past when I did my black and white conversions I believed that preserving the luminance (Lightness) of the shades of colors (represented as tones of gray) was essential. In order to accomplish that I used Convert to Grayscale as my method as it was the only one that accomplished that exactly and quickly every time. It worked very well for me until I discovered painting with color channels. In Figure 1, you can see how different methods of conversions change Primary and Secondary colors.
What you’ll notice pretty quickly is that Desaturate really does a bad job and turns everything the same tone. Grayscale preserves the luminance of every shade. The purpose of showing all the color channels is to show how each one affects the different shades.
So while Convert to Grayscale accomplished for me a technically correct image, it ran me straight into the Artistic Wall. The problem is when converting 16.7 Million shades of colors to 256 tones of gray, there will be a lot of overlap. Many different shades will end up being the same tone.