The colour balance of lights and colour rendition, Venues can help

I had to cover a stakeholders conference last week at a major venue in Central London. It was quite a standard format with presentations during the morning and round table discussions in the afternoon and the usual related trade show stands in the coffee/lunch area where networking took place.

It always amazes me that a dedicated conference style venue has so little thought put into it’s lighting facilities. I can understand a general event venue not having good lighting to it’s presentation areas when most often an outside contractor will bring in staging and lighting to suit the subject but for a venue that is dedicated with permanent staging and two dais presenting positions as well as three screens so all the audience can see you would expect to have a balanced lighting set up.

No, what we had was a mixture of halogen spots, fluorescent tubes and tungsten balanced spots. The end result attempting to shoot without flash was either a screen that was correctly colour balanced for the company colours and the speaker bathed in an orange glow or a colour balance nearer the speakers natural skin tones and a screen projecting blue instead of white images!


The Shot as originally shot. Natural colours for the screen but a tungstan cast to the speaker due to the spot lights.
The image adjusted to get the skin tones back to normal – notice how blue the screen goes. With flash washed on to the speaker a better colour balance between screen and speaker could have been acheived. But at the risk of washing the detail out of the backlit screen if the speaker and background are too close together.

The thing is that the colour balances of the lights was not the only problem. There is also another factor that few people understand about lighting is the CRI or Colour Rendition Index. This rather than being the colour of light that is cast is a measurement of the ability for that light to render colours accurately.

Under some types of light if you photograph a colour chart you may be surprised to know that the quality of the light can effect how different colours are shown. For example under a redish or warm light the different tones of red may be harder to distinguish between the different shades than under a cleaner white light.

The end result for photography in situations like this is you might be first trying to colour balance your camera to cope with a tungsten balanced or warm light source only to then find you have to further colour correct post production to pick out tones that aren’t showing correctly. The ultimate problem being the end result of “crossed curves” a situation where you need to remove Magenta from one area of a picture and Green from another – two opposites on the colour wheel, when you add in green to get rid of magenta and visa versa it just makes the opposite area worse. A no win situation.

So what’s the answer? The old school method always works well for colour rendition of throwing in some clean white daylight balanced flash. This can be set to be correctly exposed for the foreground or main subject and then the background or mixed lighting sources in the background become less noticeable as the influence of the white light fades.

But this method can be intrusive at events and isn’t much favored today by event organizers who want the pictures but don’t want you noticed taking them. So is there another solution? Well yes today there is and it’s a big advantage to the venues too. LED lighting. Not a solution for the photographer to make, one for the venues to sort.

LED lighting now comes in all forms as replacements to florescent tubes, halogen spots or tungsten bulbs, it can replace sodium or metal Halides in factories and warehouses’. And in each case the colour balance can be set to warm or clean white light.

As this new technology has become established it has started to gain credibility for it’s long life, it’s excellent colour rendition of subjects and the best thing of all for venues is the energy saving.

Although the initial cost of installation of replacement LED lighting is a bit more expensive than just replacing existing bulbs for bulbs it has the advantage of power savings sometimes to more than 50%, sometimes as high as 70% plus a bulb life that can be 9-10 times the factor of the bulb it replaces. So for the initial investment venues quite often find they have total payback on outlay within 2 years and then it’s just profit added to the bottom line!

And all us poor image makers, stills or video can have one less problem to worry about and get on with recording the event as the people saw it.

By Brian Russell

Copyright May 2014