Founded by principals Larry Shaw and Chapin Cutler in 1977, Boston Light & Sound (BL&S) has spent the last 40 years taking theatrical presentation seriously. The company has made a mission of training projectionists to handle film carefully and adjust and maintain projectors to do no harm as precious film prints make their way through the chattering machinery. More recently, as film exhibition has become a decidedly boutique practice in the shadow of digital projection systems, the company is catering to a smaller niche of the exhibition community. Today, its mandate includes jobs like setting up one-off 35mm projector set-ups for film-festival screenings, or building on-location dailies screening rooms for film productions. In August, BL&S set up a 35mm screening of Reservoir Dogs at The Theatre at Ace Hotel for the Sundance Institute’s Next Fest, and earlier this month, the company installed a pair of 35mm projectors at Duke University in Durham, NC, and at the Dundee Theater in Omaha, Nebraska, where the nonprofit arts group Film Streams is overseeing a restoration. Higher-profile jobs have included crucial roles in the roll-out of projection hardware for 70mm screenings of The Hateful Eight and Dunkirk.