If one is going to use color controls in a black and white conversion, it can sometimes be beneficial to increase the color range and separation in the file before converting to black and white. This is often most effective with images that need more tonal contrast.
Here are some ways to increase color:
1) Increase saturation or vibrance.
2) Assign a bigger color profile to the image, and then convert back to the working space, ala Joseph Holmes. He developed a whole bunch of color spaces just for this purpose, but Photoshop comes with enough. For example, I often edit in sRGB. If I want to increase the color, go to edit>assign profile>Adobe RGB. You will see the color in the image increase. Now go to edit>covert to profile>sRGB, and you are back in your working space but with more color. Note: this won't work if you edit in the Pro Photo color space, since there isn't a bigger space to assign to the image. If you use a color space with a different gamma, it will change the brightness of the lower tones. That can sometimes be useful. The reason that this is often more natural than using a curve is that this method changes color by redefining the numbers in the file, similar to raw processing, instead of pushing the numbers around, the later of which can lead to information loss, too much of which leads to artifacts.
3) Use a curves adjustment layer, and make an s-curve to increase contrast. Now change the blending mode to 'color'.
Next are two moves from Dan Margulis. He demonstrates them (and other stuff) here:
https://www.youtube.com/watch?v=RD6CghemD5U
4) Increase the slope of the A and B elements of file in the LAB color space. This takes seconds to do manually.
5) Use the "man from mars" move, i.e. pull up a curves adjustment layer while in the LAB color space. Pick the eye dropper, and click on an important color. Now adjust the A and B channels around that point as Dan does in the video.
Important: These are specific use methods. None are hard, but don't use them unless you have a reason to do so. When you do, go a bit farther than you think (as Dan shows), and then dial back the effect. Whenever doing a big color manipulation or conversion to BW, view the image at 100%, and toggle the effect on and off to check for artifacts.
In a sense, this a digital version of John Sexton's using Technical Pan film with scenes of vary low contrast. That's a way of increasing tonal separation, and that's exactly what the methods above do. Like most things, it's easy to go overboard. I mainly use a simple BW adjustment layer to convert to BW, but if that's lacking for some reason, then I'll look for ways to enhance the conversion.
Bookmarks