Thursday, 19 November 2015

Editing: Secondary Colour Grading

After balancing out the brightness & contrast and completing the primary colour correction on the clips the next step is a apply a colour grade to the footage. By definition colour grading is the process of tastefully applying a colouration to the footage to evoke a particular mood or aesthetic. In this case I have started by analysing the colouration on footage from some of my favourite films so that I can see how I need to alter my footage to get a similar effect. The first film I have analysed is Nightcrawler. From a cinematography perspective this film is stunning. However for this I am just going to be drawing influence from how the footage has been coloured. The frame that I have chosen to analyse is one where the main lighting source matches that of mine in my performance footage.


Obviously this shot is very dark with the main source of light being an orange street light. This is not too dissimilar to the lighting of my performance footage therefore shouldn't be too hard to match. After importing this into Adobe Premier I used the built in reference monitor to examine the colours of the clip. To load the reference monitor I had to go into Window>Reference Monitor. The first step is to examine the YC Waveforms. Put simply the YC Waveforms option displays the luminance of the shot. This means it shows the dynamic range of lighting in the shot. Along the information along the x axis is directly related to where the light is in the frame. For example there is a spike in the right half of the graph. That relates to the fact that that is where the streetlight is. The rest is fairly compressed with a very low level of light throughout. This isn't too dissimilar to my footage which is also very selectively lit. The graph on my footage looks fairly similar. The dynamic range isn't too extreme apart from a couple of spikes, much like the above frame from Nightcrawler. One of the slight differences is that under close examination the footage from Nightcrawler sits between 0.32-0.4, whereas my footage is slightly darker sitting at 0.3-0.38.

The next step in matching the two pieces is getting the colour right. To do this I have used the Vectorscope. A Vectorscope is a form of oscilloscope used in audio and video production. In this case it is used to examine where the colour of the footage sits on a colour wheel. It is often used to analyse where the colour and saturation of footage sits in relation to broadcast limits. I will be using it in that regard however for me the main focus is to use it to match the colour of my footage too Nightcrawler. In the screenshot to the right the Vectorscope has been used to analyse the frame from Nightcrawler. The green patch on the Vectorscope represents the colour in the clip. The graph itself mirrors the colour wheel shown above. Therefore the green patch sitting on the eleven o'clock line means that the main colour of the clip is between green and red. At the bottom the green follows the skin tone line however it tails off at the top towards the yellow/green portion of the colour wheel. After I loaded up the Vectorscope on my footage it displayed a pattern not to far off the one in the above screenshot. Where Nightcrawler pretty much follows the skin tone line and tails off at the top mine curves out towards the red side slightly and then curves towards the line at the top.