Photographer James Paterson puts cutting-edge Rotolight LEDs to good use and says they offer more control over colour than ever before
new rotolight leD lighting is put to the test
One of the most useful features of LED lighting is the ability to control colour temperature. Bi-colour LEDs, like the Rotolight AEOS heads used here, allow you to change the colour temperature with a flick of a dial. So when you’re shooting on location you can balance your LEDs with the ambient light in a matter of seconds or, if you like, experiment with unusual colour shifts and mixed temperatures.
The Rotolights offer a range from 3,150-6,300K, which goes from warm tungsten hues to cool daylight tones. What’s more, they score very highly on the Colour Rendering Index (CRI) scale: a universal rating that measures the accuracy of a light source in comparison with a reference light. A score of 85% or higher is considered very accurate – the Rotolights score 96%.
Importance of colour temperature
All light sources have a particular hue, which we can quantify in Kelvin. The scale of visible light goes from warm tones at the low end of the Kelvin scale to cool tones at the higher end. Our eyes subconsciously correct for changes in light colour, but our cameras record whatever colour is emitted. This is why we set a white balance – so that a white or neutral object looks white rather than being tinted by the colour of the light hitting it. If in doubt about which white balance to choose, it’s a good idea to shoot raw as it allows you to change the white balance after the fact.
Balancing and mixing
Colour temperature controls are most often used to balance the artificial light with the ambient light in the scene. So when shooting in daylight we can set both the lights and our white balance around 6000K so that everything is in harmony, thereby allowing us to augment the ambient light with our LEDs. Similarly, if shooting indoors under tungsten lighting, we can match up the LEDs by setting the temperature to a warmer 3500K. However, colour temperature control isn’t just about neutralising colour casts; it can also be used to create a mood or aesthetic. We have the freedom to warm things up, cool them down or intentionally mix the colour temperatures.
For example, if we shoot our subject inside, lit with a warm temperature like 3500K and include a window in the background, and with our white balance set for the warm light, then the outdoor scene will be cast in ethereal blues.
LEDs have the edge
In the flash vs LED debate those in the flash corner will point to the fact that LEDs aren’t as powerful. This is true, and it’s worth noting that the maximum output of most bi-colour LEDs drops off slightly at either end of the Kelvin range. But as the low-light performance of modern cameras continues to improve, the maximum output becomes less of an issue in many scenarios, so other lighting features come to the fore. And when it comes to colour temperature, LEDs are a clear winner.
Controlling the colour temperature of flash (which is usually around 5,000-6,000K) involves fitting coloured gels
– either in front of the flash or over the ambient light sources. By contrast, with LEDs like the Rotolight, balancing the ambient is as simple as turning the dial, and it’s much easier to judge the results as you can eyeball the light as you tweak the temperature, or switch on live view to see how it works with your chosen white-balance setting. The Rotolight AEOS also features an innovative HSS flash mode that increases the maximum output by 250%, while still allowing you to alter colour temperature – a first for flash photography.
As well as bi-colour control Rotolight kits also offer a range of circular coloured gels that let you expand your repertoire of coloured light beyond the Kelvin scale. LEDs never get hot, so these gels can be fitted in front of the bulb. Used in combination with the Kelvin settings these gels give you an expansive palette of colours, whether you want to kiss the edge of your subject with a subtle shade of blue or go for a more vibrant mix, like this portrait here.
I wouldn’t normally light a face with a combination of pink and blue gels, but the beauty of these lights is that the instant feedback gives you the confidence to try out different lighting techniques. This freestyle lighting would be much trickier and more laborious to achieve with flash. More importantly, there’s less reason to stick to the tried-and-tested lighting set-ups. With LEDs we have greater impetus to simply make it up as we go along, which isn’t just creatively stimulating, it’s also more fun.
The gels offer photographers a chance to experiment with new lighting set-ups
Balancing the ambient light source is as easy as turning the dial