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There is a camera technique which is fairly common now but was rather unusual and subtly effective when it was first used. Of course I don't know the name of it or how it is done (hence my question).
It is usually used with one or two persons in focus in the foreground against a fairly deep background. In the camera move, the background begins a zoom in, but the foreground figures maintain their relative positions within the frame. It has a subtle effect of intensifying a scene, roughly a visual equivalent of "turning up the volume".
I recall reading sometime ago that it involves shifting the picture plane of the camera while at the same time maintaining focus on the foreground but I am likely misremembering or didn't completely understand it. There is no CGI or anything like that involved – it is purely mechanical and optical.
Anyone know what this technique is called, how it is done, who invented or popularized it and also I guess, if it can be achieved with the digital cameras now in wide use?