Portraiture Masterclass - AP photographer Andrew Sydenham demonstrates to three readers how a simple arrangement of lights can produce effective portrait photography. Oliver Atwell joins them
Chiaroscuro lighting is a term that is more commonly applied to Renaissance and Baroque paintings. The style was used to introduce a sense of realism into paintings, by using the contrasts between light and dark tones to create a sense of depth. More recently, it is a technique that has found its way into the world of photography. Readers may be more familiar with the method under its less intimidating name of low-key lighting, a set-up generally shot against a black background.
‘Low-key lighting deals with the contrasts between light and dark areas,’ says Andrew. ‘It’s an expressive way of lighting your subject and is enormous fun to play around with. It’s a look that we’re used to seeing in classic film noir gangster movies, and is therefore seen as very cinematic.
‘You’re essentially using the same simple set-up that you did when you were working with the white background – namely, a single light source and a reflector,’ continues Andrew. ‘It’s an excellent set-up to use when you’re stuck with just one light source. The simplest way to achieve this look is to place your light directly to one side (around 2-3ft or 60-90cm away) and position your reflector on the opposite side. However, it may be that you want one side of the face to be completely enshrouded in shadow. If you do, remove the reflector and work with the single key light.’
Low-key lighting is a method that demonstrates the idea of ‘sculpting with light’ perfectly. ‘When you work with low-key lighting, you really begin to appreciate how you can use light to emphasise the depth of a subject,’ says Andrew. ‘A photograph is a two-dimensional medium, but using light can help us create the illusion of three dimensions. Taking the idea of sculpting somewhat literally, we can employ barn doors. Barn doors are used to control exactly where the light falls. You either open or close the doors to prevent the light falling onto any areas that you want to keep black. This can be easily replicated at home using some thick black card and taping it to the side of your light source.
‘Low-key lighting is a look that naturally lends itself to monochrome,’ says Andrew. ‘It adds real atmosphere and mystery. When you take a low-key image it’s worth seeing what it looks like in black & white. The high contrasts that you’ll get from using a single light source are incredibly dramatic. When you import your file into Photoshop, go to Image>Adjustments>Channel Mixer and click the Monochrome box. You can then adjust the Levels accordingly.’
Working at home can carry the risk of ambient light coming in through a window, ruining an otherwise good low-key shot. But Andrew has a valuable tip. ‘When you’re working in a place surrounded by ambient light, it can be tricky getting the blacks completely black,’ he says. ‘The thing to remember is that you want to keep your ISO as low as possible as digital grain will really show up on a dark image.
Before switching on your light source, set your camera to manual exposure mode and your f-stop to the widest aperture possible. You should then close the aperture down further and further (manual mode will ensure that you maintain the shutter speed that you intend to use for the shot) until any ambient light has disappeared, You’ll be able to see if you have any light from the back of your preview screen (the screen will be black). Check your histogram – the graph of the histogram should be towards the left-hand side of the chart.