From Red Dwarf in Timeslides:
Lister: Yeees... we've got ourselves a smegging time machine
Rimmer: So we can go anywhere we want, absolutely anywhere?
Kryten: Providing we have a photograph of it.
Rimmer: So if one of us had, say a photograph of a female only naturist beach in Acapulco full of bronzed, naked, uninhibited, teenage temptresses, we could go there for a holiday?
Kryten: I suppose.
Rimmer: Kryten, get my photo album.
Lister: Hang on, the thing is we can't move outside the confinds of the photograph, what we see is all we get.
Cat: Meaning...
Lister: Meaning we can't get a picture of earth and go back there, we wouldn't be able to move outside the frame of the photograph.
Rimmer: Believe me this beach shot in Acapulco you wouldn't want to move outside the frame of the photograph.
Cat: So it useless then?
Rimmer: No, not entirely useless. Think of the famous people we could meet, the famous places we could go.
Kryten: We could go to Dallas in November, 1963, stand on the grassy knoll and shout, Duck!
Awkward silence...
Kryten: Umm, I'm sorry, it must have bypassed my good taste chip.