Acting on a tip from the Lakeville Journal's Ryan Snider, I obtained the super low-budget Equinox from NetFlix and right away realized where Sam Raimi got a lot of his ideas for The Evil Dead. I mean, look at it: well-meaning professor gets hold of ancient book of the occult and foolishly reads the spells aloud as he translates from the Sumerian. All Hell breaks loose. Well-meaning students blunder into situation, discover all H. breaking loose, and die in unusual ways.
The special effects for Equinox are spectacular, given they had a budget of about $8000 (in 1967). For the giant-menacing-the-smarty-pants scene, the actor playing in the ogre stood on a picnic table; the actor playing the wisenheimer was several yards away, aligned for the camera angle. To get the "ground" right, the right color dirt was placed on a piece of plywood, which was then propped up next to the picnic table.
The Criterion Collection DVD two-fer has the original version and the later theatrical (read: drive-in) release, with extra footage shot a couple of years later and some additional plot to get in the way of the story. The later scenes are noticeable: the longer sideburns on the men are a bit of a giveaway, and the young blonde lady doesn't fit her Capri pants quite as well.
Fans of WKRP in Cincinnati might recognize Frank Bonner (who played Herb in the TV series). He's the one with the sideburns.
Summary: Four stupid white people; one berserk scientist; one evil book; one weird park ranger/demon; assorted monsters, including giant house-eating octopus (tentacles only), ogre, flying red devil, minor league King Kong; one disappearing castle; one Zone of Doom; gratuitous shots of girl's bottom in Capri pants; reporter in porkpie hat; fat shrink in lab coat. Groovy LA teen stuff. Incredibly slow speed limits. Lots of scrambling up hills. Grimace sex.