Musicvid hit the nail on the head... 4:2:0 subsampling often causes reds to "bleed" over, we hate it in the concert video industry when the lighting designer washes the stage in red for entire songs, as unless we're able to do color grading to dial the saturation back (not always easily available during live webcasts and such), the shot looks like an over-exposed red sloppy mess.

Basically, your reds are sampled at a lower resolution than the other colors, causing them to appear to bleed over the edges of objects, this is inherent to pretty much all video except stuff rendered directly from a program like after effects to certain codecs, as well as video shot by high end cameras to professional grade intermediate codecs.

The fix, of course, is to shoot in 4:2:2, but as has happened before, we are waiting for the US broadcast industry to catch up. Only then (ATSC2) will it become a mainstream consumer format.

Still, as an oldschool editor, I don't recommend software upscaling, although 1440 is certainly not out of reason. Preliminary tests I ran were inconclusive as far as any actual improvement on Youtube.

@fr0sty

Can't wait for that. We already shoot 4:2:2, but when it gets sampled back to 4:2:0 for delivery (especially considering social streaming platforms and their low bitrates being the target), red stages still get messy. Hopefully the streaming world will adopt higher yuv sample rates soon too.

I'm having a problem with scaling my 1080p videos to 4k when I do so the red colors say for example an icon on a screen or an enemy showing up on the radar (like a red dot or point) in a game red gets pixeled bad only after I render my video in 4k, Up to 1440p its okay but 4k its looks bad you can't really see any pixelation on anything but when it comes to icons, radar, in-game pop ups in red its bad. Is there a way around it or else?

So nobody actually answered his question. As for the answer, I"m not sure what is happening. You would think if you have a 1080p project and you encode to 1080p when played back on a 1080p monitor it should look the same as when playing a 4k encode of a 1080p project on a 1080p montitor, but poster says that doesn't happen but it does for 1440p encode. Any ideas?

I can only guess it's due to interpolation and how video players read the videos. with your 1080p encode everything is working as you believe it should, a red on black character will look blurry or soft, it's due to the lower resolution of red on black characters, and the video player blurring between the black and the red to make softer charcter but not pixilated. This looks to be happening in 1440p encode also, but in 4K the player no longer does that, you see pixilation instead of blurring even though still viewing on a 1080p monitor?

Is it possible that you're adding sharpening, so you are changing the encoded video, but behaves the same, except in 4K whee it's changed enough the video player will only see it as pixilated and not attempt to soften?

I"m just taking wild guess's bro, but nobody else bothered to answer you.

Or maybe someone missed the answer. Just a wild guess, you know . . .