I view my 35mm slides using a projector and a light table with a loupe, but I had this very simple and portable device when I was a child but I don't know what it was called.
You just loaded a slide into it (one at a time), and looked into the box (it had openings for both eyes) and positioned the box to allow light to come into in through a matte wall. Inside the box, the matte wall illuminated the slides. Internal lenses provided magnification, so the image filled all field of view.
I searched the internet for
slide viewer, but all I get are results about some awful devices that are powered and project the slide onto a 1.5'' ground glass. Not what I want at all.
Does anyone know what is the name of the device that I want, and where can I find one?