Colour correction is a skill which I’ve been slowly getting to grips with. My biggest challenge yet has been matching the footage from my Blackmagic Pocket Cinema Camera (BMC) with my Canon camera. This is because the two cameras capture information in very different ways.
The Canon records in a .MOV file format, with H.264 encoding. Don’t worry if you don’t what that means, what’s important to know is that it allows the camera to record HD video with a relatively small file size. This comes at the cost of being less flexible when it comes to colour-correction in post-production. A smaller file size means less information captured, which means you can’t manipulate the colours as much before it affects the image quality.
The BMC uses ProRes. This captures much more information and therefore creates a much larger file size, so when it comes to colour correction you have a lot more range to work with.
Think of it like taking notes in a lecture. The Canon notes down the key points, so that by the end you’ve got a general but clear idea of what the topic was about. The BMC covers all the points of the lecture in detail, with cute little subheading’s and the occasional highlight.
More notes = More paper SO More information = Larger file size
What this means visually is that the Canon footage looks much closer to a finished product, while the BMC is a blank slate, devoid of any striking tone or colour.
With the help of a course on the amazing Lynda.com (please sponsor me), I began the process of matching the BMC’s footage to the Canon’s. The first step was to set up a workflow where the two could be compared side by side, which I did by cropping both shots and placing them next to each other, making sure they had similar framing of the subject (which in this case is the dashing Jonathan).
Next was to match the tone, which is shown by the Luma waveforms below. As you can see, the waveform on the right (which is the BMC) is more compressed and a different shape to the one on the right.
To match the tones, you use the Basic Correction settings in Premiere to match the shape of the BMC’s waveform with the Canon’s as shown below. The BMC footage on the far right now has more depth to it than it did before.
After matching the tones of the two cameras, I then moved on to colour. This followed a similar process of matching the waveforms, this time using a RGB Parade:
As you can see, the three pairs of waveform are similar in size and shape. This is done using the curves you see on the right hand side of Premiere (the green line in this screen grab). The two are now much more closely matched:
Jeff Sengstack, the author of the Lynda course I watched, said that there was both an art and a science to colour correction, with tone being the science and colour being the art. Understanding this was key to my understanding of the skill – it was easy to match the tones of the two shots, but matching the colours was a much more subtle and subjective process.