Webster's Revised Unabridged Dictionary · 1913

Megascopic

Megascopic , adjective

1.
(Physics) Of or pertaining to the megascope or the projection upon a screen of images of opaque objects.
(b)
(Physics) Enlarged or magnified; -- said of images or of photographic pictures, etc.
2.
(Geology) Large enough to be seen; -- said of the larger structural features and components of rocks which do not require the use of the microscope to be perceived. Opposed to microscopic.

Also: Megascopical