Daughters of Darkness

Daughters of Darkness is a 1971 horror film based on the 1872 short novel Carmilla by Le Fanu. The story can be read online here.

via DailyMotion:

Moria says, "Daughters of Darkness is a considered classic" and "the most elegantly sophisticated of these [lesbian vampire films] and has become a cult classic." 1000 Misspent Hours closes with this:

I wouldn’t go as far as the overheated blurbs on the cover of the old VEC videotape (“One of the most elegant horror pictures ever made,” my ass!), but Daughters of Darkness undoubtedly is worthy of more measured praise.

The New York Times praises it, calling it "a fascinating vampire movie" and "Subtle, stately, stunningly colored and exquisitely directed". Images Journal describes it as "a stylish, cold, and sinister meditation on sex, compliancy, and vampirism."