I was going to say at the museum where I worked we called them Framing Projectors.

I think they are used in theatre as well. We have a couple relics in our church which I converted from 500w halogen to LED using a par38 spot and socket which work better than the halogen because so much light was lost in a bad reflector and the heat was a nightmare where the led just points light down into the lens…and now it’s been years since I’ve had to climb 20 some feet up a ladder to work on them…and the framing shutters stay put better without all that heat as well.