I guess he was quite the equipment freak. He used Nikon, Canon and Rollei. I found this passage in a review of one of his photo books:

"He recalls Sammy’s obsession with the latest and best equipment. “Of course once I had a little education, Sammy once said, ‘I needed a new Nikon this and a Canon that, both with eighteen lenses and sixty-two filters. In terms of addiction, I think there is nothing more powerful than men’s toys. This may sound a little paranoid but I am positive that somewhere in Germany, in Japan, there are men awake in the middle of the night thinking, ‘Now Sammy Davis has an extra $50,000, let’s think of something he doesn’t have that we can sell him, the ultimate, the definitive… he’ll jump to be the first one to have it and we’ll get that $50,000.’ I am positive of that.’”

Article here: