remove grain/resolution problems

[Litwak57]

hello,

working on a comp with r3d footage thats all been shot in 5k and hasn't been transcoded. (I know, i'm an idiot and should have transcoded). i've put some grain removal on the nebula backgrounds and because its so huge i've been working/previewing at quarter resolution and the first pic below shows what that looks like (this is a look i'm generally happy with and want to preserve)

but when I go to render (or just preview) at full resolution, it gets crazy grainy and i'm wondering how i can make the 5k footage look like the quarter res version, should i just de-res all my backgrounds? or use a different grain/noise plug-in?

thanks for your help

[Szalam · Accepted solution]

When working with effects that are so resolution dependent (removing noise/grain), you simply have to work at full resolution when you're doing that particular task. It simply won't give you accurate results otherwise.