Hello,

I edit a 4k video on Vegas pro 17 from a windows pc and I manage to render the file in optimal quality. The source file on the different players of my pc seems to be extremely faithful to the raw version of my camera. 
However, with each export I make on youtube, the 4k quality is very good but all the other formats (1080p, 720p etc...) seem extremely compressed compared to a 1080p source file.

I tried different export formats (MOV / MP4 / AVI) but the result is always the same on Youtube.

Does anyone have any advice on how to have a 4k export of optimal quality on Youtube that allows me to have a faithful 1080p?

My video is shot using a Fuji XT3 in 4k quality, 50fps and 200ms.

Thank you in advance for your answers, don't hesitate to ask me for more details if needed!