Periscope lens

A periscope lens, sometimes called a folded lens, is a mechanical assembly of lens elements that uses a prism or mirror to redirect the light through the lenses with a 90° angle to the optical axis, as in a periscope.^[1][2][3][4]

Schematic of a conventional and a periscope zoom lens

Xiaomi Mi 10 Ultra with a 5x optical zoom periscope lens camera, recognizable by the rectangular shape of its lens

Uses

The Kenworthy/Netman Snorkel Camera System, introduced in 1967 by Norman Paul Kenworthy and Bob Nettman, uses periscope lenses to allow filming very small scale models and objects from a very close distance.^[5][6]

Smartphones use periscope lenses to allow larger zoom ratios without increasing their thickness significantly.^[2] The increased optical zoom range is aimed to improve macro photography. With a periscope lens, the zoom lenses are turned by 90° and are aligned along the length or the width of the smartphone instead of its depth.^[7] The Sharp 902, released in 2004, is sometimes credited to be the first mobile phone to feature a (2x variable zoom) periscope lens camera.^[3] The Asus ZenFone Zoom smartphone, released in 2015, used an Hoya dual-periscope lens mechanism to achieve a 3x zoom.^[3][8][9] In 2019, the Huawei P30 Pro featured a 5x zoom periscope lens.^[2] In 2020, the Huawei P40 Pro+ introduced a 10x zoom periscope lens camera.^[10]

See also

• List of longest smartphone telephoto lenses