Periscope lens

[1][2][3][4] 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 (too much) their thickness.

[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.