MA Perfecting The Look: Colour Correction inside Nuke
So, now that we're starting to get to grips with the basics of Nuke, we've been introduced to another new topic this week, which is colour correcting! I mentioned it last week that my eye for colour correction isn't really something I think I have yet, but the class this week has at least shown me the tools I need to colour correct images and videos!
Setup for Colour Correcting
The main nodes being introduced were the ColorCorrect and Grade nodes, along with a few others that I'll go through. To start, we brought in some images that we would be using for the first example:
The first thing to tackle was fixing the size of the mailbox, since it was massive and went beyond the boundaries of the screen. The reformat node helps adjust the scale once the output format is set to the resolution size. We also learned a neat little trick here by setting the value next to the lock icon to 1 instead of 10, so that we can control how many panels are open at one time.
Next up, we need to set the black and white points within the background image using a grade node. This is achieved by clicking the black and white boxes next to the blackpoint and whitepoint settings inside the Grade node, and then by finding either a perfectly black / white cell within the image to use as the reference point (or a cell that is very very close to it!). The RGB values display when hovering over the image to help locate a cell that's either 0,0,0 or 1,1,1. This is set by holding Control and left clicking the desired cell, then doing the same but with right clicking to exit the setup.
Last thing to do is connect everything together, adding in a an unpremult and premult node to cull out the white backdrop on the mailbox:
Fixing the Mailbox
Now, the mailbox needs some more adjustments to it to help it blend in better with the background! I'll just summarise this one quickly and post the results:
Connect a transform node and adjust the position of the mailbox
Reformat so that it fits within the scene
Add an Unpremult node
Add a ColorCorrect node and make adjustments within the settings (such as below)
Create a Grade node and make the same adjustments to the whitepoint and blackpoint using the best cells that can be found on the mailbox
Add a Premult node
Add an EdgeBlur node and adjust its size to help blur the edges of the postbox
Connect the EdgeBlur from the mailbox and the Grade node from the background together with a Merge node before connecting it to the Viewer
With that all done, we finish off with something like this!
And for comparison, here is the before shot:
Closing Thoughts
That about covers it! I wanted to dive into doing this with video footage using one of the tutorials provided, but I couldn't spot where the video footage was saved / uploaded to. I probably just missed it, but I'll take another look to see if I can find it hiding somewhere and practice some more.