Hmm, nothing? I found that Viviclip 3 Pro will “sort of” do this. Matches general color and does something to the contrast or levels in an attempt to match.
I think I’m just going to have to build one in AE…
Thanks to both of you. I’m on PC, and it turned out to be alt< . Sorry if I wasn't clear. I'm a neophyte. I normally use After Effects with SD and DV sized comps, but am now looking into larger comp resolutions that don't fit on the monitor. I just wanted the comp window to be fully visible. Resizing the comp window to 50% via the alt< shortcut works perfectly. My confusion about proxies came from my trying to find info on high resolution comps in the manual.