Colour Correcting in Nuke: Setting a scene through colour

Following on from the last post where we looked at the basics of Nuke, this week we focussed on colours, lighting and correcting these to fit a specific aesthetic within a short scene.

Before tackling this within nuke however, we spent time recapping terms related to colour along with some important aspects that must be considered when approaching the colouration of a scene.

Considering Colour

When considering colour, it is useful to return to the Colour wheel to consider a range of factors including associated moods and ideas along with complementary colours for effective contract

It’s also important to explore how colour decisions can impact on a scene using a given aesthetic, we explored the following terms and how they can be appropriately used in a scene:

· Monochromatic – Use of a single hue (not just black and white) to target a specific mood/feel as suggested in the colour wheel.

· Analogous – Series of three colours next to each other on the colour wheel that emphasise a certain mood. It’s also worth noting that when approaching realism in shots, analogous colour schemes are often found in the natural world and can be linked to a sense of comfort in design choices.

· Complementary – colours on opposing sides of the colour wheel. Often used to draw the audience attention to specific areas within a scene or image.

Colour in Nuke

When approaching colour in Nuke, there are a range of nodes that can be used the manipulate the colour of both the background scene and the foreground assets.

Initially we were informed of the importance of setting both the white and black for the backing video footage, this would allow us to appropriately manipulate the colours within the scene. In practice what this meant was scouring the footage for the area which had the closest values to 0 (black point) and the area closest to 1 (white point). Through setting the white and black points in the scene we were able to ensure that the colour changes we used would impact the scene in the most accurate way (despite the task being somewhat of a game in terms of locating the closest values).

Following this we were asked to explore the ways in which colour correction could be changed both in the scene and within out object using the colour change node as well as the premultiply and unpremultiply nodes (both of which are needed to bring the CG asset into the scene and for it to be accurately rendered).

As you can see from my trials with this however, I ran into an issue wherein the top image was partially transparent (the object was renamed the “Ghost box” as opposed to post box) on this account.

Following the unforeseen creation of the ghost box, we looked at how to avoid this through creating 2 pathways from the initially image to ensure that the overlayer would retain its opacity and not become transparent.

The final area we explored was the use of the Write node and how this allows you to render your scene. When rendering there are a number of choices available to the user in terms of how to output the file - this is where reflecting on whether you will further edit the file comes in handy and reviewing the need for potentially rendering the footage with higher compression or not.

Further research and investigation

During this week’s review I mentioned how we were exploring colour and setting that within a nuke scene. One thing that was mentioned was the Panatone colour of the year. After some base line research, I discovered that the colour is named Very Peri (a pale bluey purple). Considering the need for this project to show a range of skills and industry consideration I plan on exploring how I may include this colour in my final project, which presently is very vague – but will most likely include some form of sci-fi element.