Until your comment I didn't realise I'd also read it wrong (despite getting the gist of it). Attempted rephrase of the original sentence:

Imagine history documentaries where they take an old photo, free objects from the background, and then move them round to give the illusion of parallax.

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necovek 18 hours ago | parent | next [-]

I'd suggest a different verb like "detach" or "unlink".

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thenthenthen 15 hours ago | parent [-]

isolate from the background?

	▲	necovek 8 hours ago \| parent [-]
		Even better, agreed!

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nashashmi 15 hours ago | parent | prev | next [-]

Free objects in the background.

	▲	Sharlin 14 hours ago \| parent [-]
		No, free objects in the foreground, from the background.

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tzot 18 hours ago | parent | prev [-]

> Imagine history documentaries where they take an old photo, free objects from the background

Even using commas, if you leave the ambiguous “free” I suggest you prefix “objects” with “the” or “any”.