As I said in the last entry, there are several techniques for converting an image to black and white that I recommend you do not use. But that doesn’t mean that these techniques are without merit. The reason that I don’t recommend them is because they give very little control over the conversion process. But these techniques can be used as a part of a technique where an artistic conversion is not required. There are quite a few techniques used in Photoshop where colour information needs to be stripped from an image, and very often the techniques described in this post are perfect for that, because even though they lack control, they are quick and easy. And if the technique doesn’t require a great deal of fine tuning, then it’s a waste of time to use one of the more complicated techniques.
Technique 1 – Shooting Monochrome
The first technique I caution against is using the monochrome option on your camera. This gives you few options to adapt it to the particular image, although some cameras can simulate the look of different coloured filters over the lens. But the biggest drawback to this method is that once the image is shot, you are stuck with the black and white version. There is no way to put the colour information back into a black and white jpeg. Of course, you can get around this by shooting in raw, but then you will have to convert the image to black and white later anyway (unless you are using the brand specific software that came with your camera). Photoshop’s Camera Raw developing software tends to discard the information in the raw file that would convert it to black and white. In short, I recommend that you don’t use this technique at all.
Technique 2 – Desaturate
The second technique I recommend against using is the desaturate command in Photoshop (control-shift-U or image/adjustments/desaturate). This just strips all the colour away, giving you no control over the process (a hue/saturation adjustment layer with the saturation taken to -100% gives exactly the same effect – but at least the adjustment layer is removable). While it doesn’t give much control, it is a perfect method to use as part of a larger Photoshop technique which requires getting a colourless version of an image.
Technique 3 – Grayscale
Another technique I recommend against using is a conversion to grayscale (image/mode/grayscale). Like the desaturate method, this technique gives you absolutely no control over the process. But, unlike the desaturation method, this affects the entire image, so it can’t even be used as part of another artistic technique. The only value in this technique is that it drastically reduces the file size, so if you create a black and white image using a different technique, you can convert to greyscale to make the file size smaller. But honestly, this isn’t worth that much. Memory is cheap these days, and there’s no point in applying this to a layered file like a PSD (why maintain the ability to edit layers if you don’t have the ability to edit colour?), so this is another technique that is just about useless.
Technique 4 – Solid Colour (with optional dodge and burn later)
A third very basic technique, barely any better than the other techniques in this post, but it does have an element of flexibility in it that makes it marginally useful.
Start by creating a solid colour adjustment layer, filled with black. Then set the blend mode for this layer to colour. This strips away the colour information from the image, but since we are working on an adjustment layer, we haven’t actually removed any of the colour information. Our background layer, with the colour information intact, is still there.
The only flexibility for this method comes from the fact that we can create a dodge and burn layer underneath the solid colour layer. Press Shift-Control-N to bring up the new layer dialogue box, set the mode to Overlay and tick the box that says, “Fill with overlay-neutral colour.” When you click okay, you’ll get a grey layer that doesn’t change the image at all. But if you use the paintbrush to paint black or white on this layer, you can selectively brighten or darken parts of the image to fine tune the effect. I recommend that you use a soft edged brush with a low flow so you can build up the dodge and burn effect gradually.
Still, this technique doesn’t have much going for it. Applying any kind of fine tuning to it is time consuming, and we can’t choose to alter sections of the image based on their colour (such as brightening all the reds). The other methods we will look at, starting in the next post, give much more flexibility in how the finished black and white conversion comes out.