After years of being told how great the RGB capture system in our cameras is, a small company in New York is redefining the very way that we think about digital colour

The shortfalls of RGB
It is not that there is anything wrong with the tricolour system of capture, it is just that it doesn't replicate fully the way that our eyes see the world. Yes, cameras that have a matrix of individually filtered red, green and blue sensor sites are capable of capturing many millions of colours, but the guys from Tribeca Imaging Laboratories say that, despite the numbers of possible variations, 'the hues are not arranged in a way that is consistent with how we see'. They say that as a result of this mismatching of what we see and what our camera records, that our digital photographs are created with a simplified and limited spectrum.

'Okay' I hear you say, 'but how does this affect how my photographs look?'. Even though the inaccuracy of the RGB colour model occurs throughout the whole spectrum, it is most noticeable in violets, indigoes, blues and greens. It is with these hues that the RGB model fails to fully replicate our vision. Violet flowers just don't seem as richly coloured when photographed. Blue skies not as deep and green grass not as vibrant.

Don't believe me? Well try this test for yourself. Direct your web browser to the company's website (www.tribecalabs. com) and then point your digital camera at the home page. Take a photo and view the picture on the LCD of your camera. Notice how the portrait of a girl on the left of the screen is recorded as blue and not the purple that your eye sees.

A new way to colour
With these spectral shortcomings in mind, Mike Bevans and the guys at Tribeca Imaging Labs set about defining the problem and providing digital photographers with a solution. After three years of empirical research, that involved testing dozens of cameras and tens of thousands of images, they produced a method for compensating for the inaccuracy in the RGB capture system.

The solution takes the form of a colour difference model that accurately describes the parts of the spectrum where the RGB colour model falls down when compared to our own vision. With this data in hand, it was then possible for the team to build a Photoshop plug-in that could translate colour images stored in a linear RGB colour model to a complex non-linear model that equates more fully to human colour perception.

DCF Full Spectrum
The DCF Full Spectrum plug-in works with a device independent colour model that sits inside the current RGB system. It works by remapping existing RGB values so that areas that traditionally have been under-represented in the model are more clearly defined. In practice this means the most noticeable changes are apparent when applying the DCF plug-in to images that contain large areas of purple, indigo, violet, blue and green.

After installing, remapping is as simple as selecting either one of the auto options (File > Automate >Full Spectrum, Vivid or Portrait), or by choosing to take a little more manual approach with the slider controls in the DCF Full Spectrum dialogue. Either way produces better, more accurate colour quickly and easily.

Best uses
Nature and landscape shooters, product photographers and image makers concerned with capturing truly accurate colours will all find this plug-in a real god send. And let's face it, great colour never a bad thing, so the rest of us will probably hanker after this tool as well.