Colour is one of the most important features of an image. It can radically alter our perception of what we see. Colour is directly linked to psychology and has always been used for triggering emotions through history. It has been present in every form of visual communication, from paintings to choice of clothing and, of course, cinematography. By colour grading a digital image we can make it more attractive to the eye or change the viewer’s perspective on the subject.
Starting from the basics
In videography, colour correction and grading are key to a visually appealing footage. It can be so complex that there are post production professionals who specialize in this process only.
The way we perceive colour is determined by the different kinds of light. We find two main colour atmospheres in digital imaging: Warm (colours approach the orange spectrum) and cold (the range of colour is closer to blue).
This parameter is called colour temperature and it’s considered basic knowledge in the audiovisual field. In the case of natural light, the position of the sun and the weather conditions can make the image look warm or cold. It’s the same with artificial light: the colours will look warmer or colder depending on the kind of light bulbs in the room.
Our case studies
As a filmmaker, the ideal scenario is to achieve the colours you want straight when you’re filming. That happens when you use specific lighting and camera settings to obtain the look you’re after or when that visual scheme is already present in the location. However, this is not always possible. Sometimes you will have to film a grey building on a cloudy day and there’s no camera settings that can help with that. Here’s when colour grading can come really handy.
Here are some real examples of situations we have faced in different shoots:
Cloudy days can help to have a soft lighting and get rid of hard shadows, but in return the sky doesn’t look great. If you add a grey building to the equation, the result is a rather flat and sad looking image.
In this shoot for i2eye Diagnostics we reduced the overall levels of yellow, then selected the sky area and applied a blue filter to cover up the grey. As a little extra, we scattered some white clouds over the original to turn the weather around. Not only the sky looks happier, but it helps the building stand out.
When filming events, it is important to remember that the lighting in the venue is out of our control. That is why sometimes a correct camera setting is not enough and we eventually need to retouch colour afterwards.
In this case, we were at the Assembly Rooms, a beautiful and elegant venue in Edinburgh’s New Town. The problem was that there was a clearly dominant warm lighting provided by massive chandeliers, together with bone coloured walls. It looks beautiful to the human eye, since our sight balances colour automatically. Cameras are not that clever and feel “overwhelmed” by so much warmth, which gave us an overly orange raw footage. First we had to make a white balance correction in order to distinguish pure whites from warmer colours. Then we balanced the colour temperature by bringing orange and yellow a bit down and cold colours a bit up.