Before digital cameras came on the scene, I always carried two cameras. One was loaded with transparency film and the other with black and white film. Problems arose when you took a shot in black and white and by the time you got the other camera up to your eye the picture had gone. You had to be a master juggler to swap bodies and lenses quickly. Today, this problem has been resolved - simply shoot everything in colour using a digital camera then convert it to Greyscale on a computer. Simple? Well not quite, one resolved problem always seems to create a new one. In this feature we are going to show you how to get the best from your monochrome images using Photoshop or other imaging application, a decent photo inkjet printer, and a few tricks.

Original shot in colour	Converted to Greysacle

b/w or colour?

You are not going to fit more pictures on your memory card by shooting in b/w - a digital camera captures images using a three filter CCD (RGB). Setting your camera to shoot in b/w simply desaturates the file and you lose the ability to tweak the image at a later stage. It’s easy to convert any colour image file into greyscale with most imaging applications.

Converting to greyscale

The simplest way to convert to greyscale in Photoshop is to select Image > Mode > Greyscale. This merges the three colour channels (RGB) into one single channel and reduces the file size down to 33% of its original size (three channels make up a colour image). Another method is to desaturate, Image > Adjustments > Desaturate, or use a shortcut key stroke Ctrl + Shift + U. The desaturate method leaves the image in RGB mode, although it has discarded all the colour information. Use this last method if you want to apply a colour tone such as Sepia etc. Although I use the desaturate command from time to time, it is not a very precise method, I will show you why later in this feature.

An image which has been converted to greyscale, or desaturated, probably looks flat and dull. This can be easily fixed using Brightness/Contrast, Levels or Curves. The Brightness/Contrast is limited to basic overall adjustments, whereas the Levels (Ctrl + L) gives you extra control on the mid tones. The best option is to use Curves (Ctrl + M). This may take a while to get to grips with, but it allows you to fine tune any tone in the image.

Brightness & Contrast	Levels
Curves

Using the Channel Mixer

Don't overdo the Blue saturation on the Hue/Saturation palette

A more advanced method is to use the Channel Mixer which simulates traditional glass photographic filters such as Yellow, Orange, Red etc. For a more dramatic sky increase the intensity of the Blue sky first. Press Ctrl + U to open the Hue/Saturation… panel and select the Blues from the Edit drop down list. Move the Saturation slider to approx 30, or other desired amount, but be careful not to overdo this as you can end up with unwanted artifacts. (in the sample picture above I have used a value of 95%, look at the mess it has made of the clouds)

The Channel Mixer panel	End result

Launch the Channel Mixer, Image > Adjustments > Channel Mixer. Make sure the bottom Monochrome box is ticked, your Output Channel will now read Gray. Move the Red Source Slider to approx 150, and reduce both the Green and Blue by –20 and -30. The total value for any adjustment combination should be as near as possible to 100, this avoids blowing out highlights. You can use any combination of sliders to achieve 100%, slide the Green slider to 150 and reduce the other two to –25 and this simulates a green filter by lightening the foliage. The bottom Constant slider is for reducing, or increasing, the overall brightness of the image. If you had shot your original image in b/w mode, then using the Channel Mixer will have no effect on your image, you must use a colour image.

Tinting techniques

Once you have achieved the correct tonality in your b/w pictures you can add a colour tint for effect. Make sure that your b/w picture is in RGB mode – Image > Mode > RGB Color. The simplest way to add a colour is by using the Colour Balance sliders (Ctrl + B) and move the sliders until you have the desired tone.

Using the Colour Balance to define a tone

Alternatively, use the Hue/Saturation… panel (Ctrl + U) and make sure the Colourize and Preview buttons are ticked. Reduce the saturation to approx 10 and then move the Hue slider to find the colour you want - you will see the colour on screen change. Increase or decrease the Saturation to taste.

Using the HSL panel to define the tone

Duotones

Probably the most sophisticated way to achieve great tints in your monochrome pictures is to use the Duotones feature. Convert your image to Greyscale - Image > Mode > Greyscale, then convert it to Duotone - Image > Mode > Duotone. You can only convert a Greyscale image to Duotone. A Duotone palette opens, from here you can select Monotone, Duotone, Tritone, or Quadtone. Select Tritone and then click the Load button, this should take you into a set of preset values supplied with Photoshop. Navigate your way to the Presets Duotones/Tritones/ Pantone Tritones folder and select the Bl 172 orange Bl 423 grey file. On the left side of the palette are a set of curves, click on one to open up the Curve for the corresponding colour and adjust to taste, click on the colour swatch to change the colour – remember to keep the lightest colours at the bottom.

Using Duotones for defining the tone (Tritone in sample)

©Vincent Oliver 2002 www.photo-i.co.uk