image by Daniel Lévesque (Image rights)
The CT-20 is an SLR introduced by Cosina circa 1980. The camera offers aperture-priority autoexposure using an electronically-timed, vertically-traveling shutter. There are no manual shutter speed settings available, besides "B" and the X-sync speed of 1/100th sec. The Vivitar XV-20 appears to be a rebadged version of this camera. It is similar to the Cosina CT-10, but adds an electronic self-timer with a blinking indicator light.