So I downloaded a blend from blendswap and here's the issue. When I load it, it's fine. When I render it, it's initially fine. Then there's something like another layer or something added on top of the render and it becomes very blurry. I am working in 2.8 with Eevee but the same thing is happening in cycles. The original version before the "extra layer" or whatever it is as well as the blurry version can both be found below.
EDIT: I've added a picture of the compositing nodes as well.