Most classrooms are still equipped with overhead transparency projectors. They are no longer used to the degree they were before classrooms were equipped with video projectors, and are not being replaced as they fail. If you need one in a classroom that is not permanently equipped with one, please contact the A-V department.
Kodak has stopped manufacture of slide projectors, so the A-V department strongly recommends that slides be scanned and stored digitally. Until this can be accomplished, there are still a number of slide projectors available. Some classrooms are permanently equipped with them, and projectors, lenses, remotes, etc. can be borrowed for use in other classrooms.
While rarely needed today, A-V still has a few 16mm motion picture projectors, which can be used on an on-call basis.