The Secret to How Movies Move You: the Importance of Colour Accuracy

Regardless of whether you are talking about movies, pictures, or any other visual medium, for any creative work that is based on visuals colour is an element that plays a vital role on which the whole work is centred. A good use of colour allows the viewer to understand the intentions of the director or discover their individual style. Sometimes they may use vivid, rich colours, while other times they may use dark or pale colours. Even if there is no dialogue or no person on screen, and the image is just scenery, colour can affect the audience’s emotions.

Conversely when a scene with a rich palette features inaccurate colours (such as colours that feature an overall blue or yellow tint) that do not line up with what we imagine in our mind, we might get a sense that something about the film’s style is “off”. Outside of letting us know that our video equipment is lacking, this phenomenon will also bring down the quality and level of enjoyment we get from the film.

In our time, movies have become a necessary staple of life. Given this, how to get the most precise and accurate colours out of our audio-video equipment has become a question of growing importance, especially when you are talking about the many consumers who dream of creating their own customized home theatre. Whether it be for space where they can relax after a long day at work or a place to enjoy movie time with their loved ones, these home theatres need projectors that can ensure that the colours the director envisioned are properly translated, thereby making the cinematic experience something that can’t be missed.

Having discussed colour gamut, the next step is to discuss the requirements for Rec. 709 colour accuracy as defined by the ITU. The ITU declared that the Rec. 709 white balance’s colour temperature must accurately display all the colours of the D65 colour temperature. However, beyond white balance (W), the six RGBCMY colours must also be calibrated accurately and must conform to Rec. 709 standards including its requirements for colour coordinates and colour brightness. Thus, only when a calibrated projector’s dE2000 value is below 3 can it be properly called a color accurate projector.

When asked whether a projector is colour accurate or not, it is often times difficult to explain in words the accuracy of colour. An easier way to answer this question is to ask how small the difference is between the projector’s colour and that colour’s standard version. As a result, once a projector’s colours have been professionally calibrated, we judge the performance of the projector using a colour difference standard that's as close to the human eye as possible. 

Delta E (dE) 2000 is a way of calculating colour difference that is very close to what the human eye sees. It represents the difference between two colours with a numerical value where the lower the value, the smaller the difference between the two colours is. In theory a dE2000 value of 1 represents the limit at which the human eye can differentiate 2 colours. In other words, if the value is lower than 1 the human eye will not be able to tell the difference between the two colours. Generally speaking, when the dE2000 value is between 3 and 6, the colour accuracy is good enough for commercial use, but not quite good enough for professionals working in the print or video production fields. 

Properly calibrating projectors using professional technology can ensure that each purchased projector’s dE2000 value is lower than 3, and once the dE2000 value is lower than 3 the projector is considered colour accurate. 

In terms of colour accuracy for the human eye, dE2000 is used as a means of calculating the difference between two colours as well as standardizing the range and tolerance of colour perception in humans. In general, a dE2000 value between 3 and 6 is a difference in colour that is acceptable to most.

Every home theatre projector is made up of mechanical, electrical, and optical components. Only a solid design that employs superior optics allows the projector’s colours to flourish. Furthermore, during the production phase each projector must be processed by special instruments and calibration software in order to fine tune its colour accuracy, including calibrating its gamma, black level, white level, neutral grey, RGBCMY colour tracking, hue, saturation, brightness, and other qualities.