It is correct to compare this independent, low-budget, black-and-white atmospheric horror film with others of its decade, such as "Carnival of Souls" and "Night Tide," and it's also correct to compare it with Bergman, since there is clearly a touch of "Seventh Seal" here and possibly a bit of "Virgin Spring" and "The Devil's Eye." But I'd like to point this out: the most obvious comparison people make is with "Persona" because of the strikingly composed "sister" shots, which evoke the famous profile compositions of Bergman's movie, yet "Persona" was made a year later, in 1966! ("Hour of the Wolf" was made three years later, in 1968.) Therefore, while we can say Leslie Stevens and Conrad Hall were influenced by Bergman, it's also reasonable to suppose that since this film played at the Venice Film Festival, Bergman might have been influenced by "Incubus"!
The awkward moments--I'm thinking especially of the last scene--create a rare accident that only occurs in low-budget films. The effects are so obvious and ludicrous that you're half-inclined to ridicule the scene with an "Oh, come on!" Yet at the same time, what it's trying to get across is so inherently disturbing that you also feel the frisson of real horror. It's a kind of accidental alienation effect. This state of conflict in the viewer's mind--half pitched out of the spell and rejecting what we see for what we know, and half shocked into ghastly conviction--this frame of mind is where is the uncanny takes effect.
