Robert Ableman, a 38-year-old convicted pedophile who teaches at a Brooklyn yeshiva, was charged with disseminating indecent material to minors and failure to register as a sex offender with state authorities.  He posed on the Web as the head of a modeling agency, allegedly scamming dozens of teenage and pre-teen girls into meeting him and posing naked for videos.  He was picked up at his home where police found piles of pictures and videos of girls as young as 12 posing in lingerie or nude.  Ableman served a prison term in California after being convicted of sexually abusing a minor, indecent exposure and aggravated harassment.  When he moved to Midwood last July, he never registered as a sex offender as required by law.