Why are some 4k movies downscaled directly to 4k and others to 2k, then upscale to 4k?


Title, I recently got John Wick 1 and 2 and noticed 1 was native 4k while 2 was upscaled from 2k. From what I’ve read movies are shot at very high resolutions, like 8k, and then downscaled to look crisp. What’s the benefit of downscaling and the upscaling?


Movies are typically recorded at 2k resolutions, and then upscaled to 4k for Bluray/UHD releases. Very rarely are movies shot at higher resolutions than 2k. Even animated movies are still rendered at lower resolutions to save time on rendering.

There are no benefits to downscaling and then upscaling. It will always result in lower quality images.

Netflix is the only company who has recently required that their movies and shows be recorded in native 4k.

4K uses a lot of data: The raw video format uses more than 1 GB per second, which is obviously way too much even for blu-ray. So they use compression to cut the movie down to size. The compression algorithms they use for this are so good that you hardly ever notice in a movie. But they do cause artifacts – moving object become more and more blurry, sharp contrasts are washed out. If the movie is too compressed, details such words on a letter or newspaper might become unreadable. The longer the movie they want to fit on a single 100 GB blu-ray disk, the more they need to compress it, and therefore the more of these compression artifacts will become noticeable.

For John Wick 2, the 20 minutes extra length probably meant that they could no longer fit 4K without degrading the quality so much. So they decided to use 2K instead, but with a higher quality compression setting.