ok a few hints:
The move came out in 1983 and was the first in the trilogy.
was Directed by James Sbardellati and start Rick Hill.
I'm quite sure the picture you posted is from the second "Deathstalker" movie, not the first one. Instead of Rick Hill John Terlesky plays the titular role. Oh, and it's actually a tetralogy, the fourth part was made in the early nineties...