As a Nikon user, I have no direct experience with Magic Lantern (always a bit bummed about that) but I was also wondering the same.
I don't know if these are presets or something done in post-processing, but it almost looks like the video equivalent of filter plugins in some cases.
I'm by no means an expert but color grading video is often a detailed process with a lot of room for finding your own creative "vision". Think of the split toned, green/orange aesthetic that was popular in movies for a while. Doing the color grading can have a major effect (good, bad, or just different) on the mood of a video.
In these examples, I was definitely impressed with some aspects of how curves were adjusted to bring up shadows and make details more visible. But at the extreme end, it reminded me almost of the overkill seen in early HDR photography.
Some tweaking can make things look more realistic and bring out detail but it is very easy to go too far and end up with something that looks like an Instagram filter.
That's mainly why I was wondering if the video examples were in-cam presets when running Magic Lantern, or if it was something the videographer did in post with the extra data captured with the higher bit depth enabled.
You can’t use in-camera presets if you want RAW. That was shot RAW, with the expanded bit depth that Magic Lantern affords. Then, it was loaded onto a computer and graded. I personally only use the presets to get more depth out of the space-efficient photo/video encodings by lifting blacks before they get cut off or turn out so dark you can’t get accurate colour out of them, or to do that in the digital viewfinder only before saving as RAW. The more finished-looking presets are fun for previewing but not all that useful otherwise.
Presumably the added greenish-yellowish cast and over-the-top HDR contrast mangling were intentional.
It should be theoretically possible to do anything to each video frame that you can do to a still photo, including moderate/tasteful color & contrast adjustments.
He's just doing a popular look after he downloads the video from the camera. It's sepia just because the popular look at the time was sepia and very bright.
I mean, even then, "improving" is entirely subjective. Color grading is the process by which you edit a video to perform global color/tone adjustments, but I don't understand it as being strictly about improving, you might want the video to look old, in which case you'd grade it in a way that it deteriorates.
Really it is not that subjective, there is an art to it, there is some nuance to a mood or style you are going for but there is a definite good and bad.
“Good” or “bad” printing (to use the darkroom photo term) can only really be defined relative to artistic intentions. There are many possible choices to make in producing a final image, many competing aesthetic goals which cannot all be satisfied simultaneously, and no “right” answer.
Some photo printers love to allocate almost all of their available contrast to large-scale shapes, producing essentially silhouettes. Others like to allocate almost all contrast to local fine detail, leaving the image looking like a gray blur from afar but detailed and crisply textured from close up. Some photographers like their images to be a festival of competing intense colors, while others make nearly monochromatic images in one color or another, or stick to a pastel palette, or make mostly neutral images with a few intense exceptions. Etc.
When someone says a photo or video was printed badly, what they usually mean is that either (a) the printer had shallow aesthetic judgment or boring artistic goals, and/or (b) the printer lacked the skill to effect their artistic vision.
