This is a great video from Canon and Alex Buono, who is the DP for SNL, covering the 4K workflow with the Canon EOS C500. As Buono points out, 4K is important in today’s 1080 world for both reframing options on some projects and future-proofing others with a 4K master.
In the video, Buono shows how the 4K workflow is different with three external recorders: the AJA Ki Pro Quad, Codex S Recorder and the Convergent Design Gemini 4:4:4. Notably, they shoot to an external recorder and internally using CF cards to make the workflow more efficient. While the editor is working on the edit with the MPEG footage from the CF cards, the colorist is working on a ProRes 4K master, which goes back to the editor for the final output with both editing and grading is done.
Buono gives a great explanation for the workflow and brings all the moving parts together to make it understandable in almost layman terms.