Non-reversing mirror

If the joint is positioned so that it is vertical, an observer looking into the angle sees a non-reversed image.

With this type of non-reversing mirror, that there is usually a line down the middle interrupting the image.

The Museum of Illusions refers to this type of mirror as an "antigravity mirror" because as it rotates once around the line-of-sight axis, the reflected image rotates twice, appearing upside-down when the joint is horizontal.

A third type of non-reversing mirror was created by mathematics professor R. Andrew Hicks in 2009.

The thousands of tiny mirrors are angled to create a surface that curves and bends in different directions.

Comparison of the images of an ordinary mirror (left) and the first type of non-reversing mirror (right)
Comparison of reflections of a pen in an ordinary mirror (left) and two perpendicular mirrors forming the first type of non-reversing mirror (right). The latter also illustrates the visible line in the middle if measures are not taken to minimise it.