So, _Black Candles_ is a movie, I guess.
The plot is paper thin: a couple - Carol, and Robert - go to house. There are devil worshipers. That's really it, that's the movie.
So, what's actually filling the runtime? Sex, loads of sex. Look, I'm not someone who complains about sex in a movie - _Cheeky_ (2000) is one of my favorite movies - but it needs to add to the story, it needs to push the plot forward. To makes matters worse, there are only two people who are worth seeing nude - Helga Line, and Vanessa Hidalgo - everyone else... no comment.
The only highlight was Hidalgo. As already stated, she is nude - for most of the movie - and she is stunning.
As for the horror element: there's only one moment that qualifies, involving a sword.
Just an utter waste of time, boring, the ending was garbage. I have other major problems with this, but if you're a fan of sleazy horror - almost like Jess Franco, only without the ineffable charm - you might like this, but probably not.

Post script: There is a scene in the second act where I had to question if I was seeing what I thought I was seeing. "Is that guy jacking off a horse?" Uh, yeah, he was. Only a few scenes later, a woman is jacking off a goat. I need to point out that I don't mean that they are acting, no, they are masturbating animals, in full view. Yet again, a few scenes later, a woman has sex with a goat; I suppose, to the film maker's credit, that part is acted, and a goat did not actually penetrate the woman. I think most people would agree that this is all quite sick. I take it the director liked the idea of beastiality (not sure I spelled that correctly, and I'm not about to run a Google search to find out). Look, I shouldn't have to explain why it's wrong to have sexual contact with animals.
One final point: If you purchase dairy products, you are paying for humans to have sexual contact with cows. The reason cows produce milk is to feed their babies. The way this is conducted on farms is for humans for jack off a bull. They collect the sperm. They shove their arm into the female cow's ass, and inject the sperm. The cow gives birth, her baby is taken away, and this process is repeated until the mother's body gives out, then she is killed. If you buy diary, you support this process.