Eighteen months ago, Charlotte Brohi and the Houston Museum of Natural Science (HMNS) had a big decision to make. Attendance at their IMAX 15/70 theater had been declining steadily from a high of more than one million visitors in 1991. With only 273,000 ticket buyers in 2011, Brohi, who is the VP of film, programming and distribution at the museum, knew they had to make a change.