Exported MP4 looks softer than the original even at the same resolution

Question

The source and output are both 1920×1080, but fine hair and small text are visibly softer after export. I matched resolution and frame rate. What else should I compare before blaming the editor's image quality?

ArchiveFlow · Answer

Resolution alone says little about compression quality. Compare source and output bitrate, codec, chroma subsampling and how many lossy generations the media has already passed through.

PhoneVideo · Answer

Export the same difficult 10-second section at several bitrates and find where extra bitrate stops producing a meaningful visual improvement. Fine text and moving texture are good stress material.