When did "portrait" and "landscape" first come into use to describe page orientation?

[Giles]

@Exapno_Mapcase

It would be helpful if Giles posted the 1932 use from the OED. Assuming that it is the modern use, it was around, at least in the technical world, long before PCs. Whether it came from printing or photography is an interesting question.

My belated response:

[QUOTE=O.E.D. s.v. landscape]
The frontispiece .. may be printed either upright (termed portrait) or broad way (termed landscape). If a full-page illustration be printed landscape, the inscription or caption beneath must read from foot to head.
[/QUOTE]