EXCLUSIVE: Robert Katz is about to begin discussions to exit as president of Dimension Films, a job that is proving tough to fill for the long term. Katz, a well regarded exec who had been Film Department’s president of production and before that exec veep at Yari Film Group, took the job in late July following Brad Luff’s exit after less than a year. I’m told that the exit is fairly amicable and that it came down to a difference in vision between Katz and his boss, Dimension head Bob Weinstein, who has always been a challenging guy to work for. I’m not sure that Katz really had an opportunity to get on track in such a short time, but clearly the chemistry wasn’t right. Dimension last released Apollo 18, the $5 million budget “found footage” genre thriller that grossed $17.6 million domestic.