Waist-level finder

The waist-level finder (WLF), also called waist-level viewfinder (WLVF), is a type of viewfinder that can be used on twin lens and single lens reflex cameras.

While it is typically found on older medium format cameras, some newer and/or 35 mm cameras have this type of finder (perhaps as an option).

In the reflex camera, the light from the lens is projected onto a focusing screen.

The waist-level finder makes this screen viewable from above, where the image is seen upright but reversed left-to-right.

[1] The eye-level finder is an evolution of the waist-level finder, using a roof pentaprism or pentamirror to correct the image while making it viewable through an eyepiece at the rear of the camera.