In Render view, to make the Mantra render zoom to the actual dimensions set by the camera, e.g. 4K, so it zooms in, is there a hotkey?

All I seem to be able to do is spacebar-G to centre the image to fill the viewport. But this is a zoomed-in view of the actual render.

I think it's H, same as the 3d view.

No, that's the same as G key -- it just centres the image to the full render window, it doesn't expand it to its actual dimensions.

litote
No, that's the same as G key -- it just centres the image to the full render window, it doesn't expand it to its actual dimensions.

H or G centers it and makes it 1:1 pixel size. shift-G or shift-H make it fit the full frame to the render pane by zooming out.

Actually, If I use either with or without shift key it does not zoom to actual size, it just centres in viewport. Is it supposed top zoom in if the image is large, say 1920x1080 to the actual size?