Compression issues with S-log 3 footage low light

[Marc Wielage]

Very dense blacks are a huge challenge for any compression engine. My response would be to try to go for an image hosting site that has less compression. Vimeo Pro might possibly be a solution.

If you put up some test signals with just a black screen or various shades of gray, you’ll often see the same problems. These are known compression artifacts. Compression is evil.

There are also issues with 8-bit video in general from DSLRs, but if what you see on your own display is good, and it got a lot worse online, clearly the problem is the online compression. Whether you can change your own compression method would be a question of experimentation.