Architecture in Photography

Linear distortion

In taking photos of façades, ravine-like streets, or the soaring bell-towers of churches or town-halls, photographers, if their technical equipment is inadequate (lack of special wide-angle lenses or professional cameras), still to this day run the risk of linear distortion: in other words, the risk of the soaring lines of such buildings being reproduced as if they were slanting (cf. the photo with the apparently ‘leaning’ tower of the Palazzo Pubblico in Siena). For the camera, it too, is subject to the laws of central perspective. To avoid this danger, the picture support (negative plate, film plate or, as in digital cameras, the sensor) should be placed parallel to the object to be reproduced. If the camera is tilted, for instance to take into the viewfinder a larger part of the building being photographed, corrective techniques are needed, so as to avoid linear distortion. In photographic manuals, which began to circulate at an early date, and which served as guides not only for professionals, but also for amateur photographers, lengthy sections were already being devoted to how to overcome such perspective problems. By the use of an optical bench it was possible, even early on in the history of photography, retrospectively to correct linear distortions in photographs. In his book of common photographic errors (Fotografisches Fehlerbuch, 1895) the head of the Photographic Institute at the Grand-Ducal Technical University in Karlsruhe thus offers some tips about how to make subsequent corrections to such distortions in the positive by the use of an optical bench. The positive is placed at an appropriate angle and re-photographed, whereby the focus screen of the camera is aligned at the same angle, though the opposite way round. The converging lines are then evened out in the reproduction. Today the problems can be solved also in another way. With the aid of photo processing programmes and special software to adjust the perspective, distorted lines can retrospectively be corrected. In professional photo shoots, using appropriate high tech equipment, however, this correction usually takes place during the actual photography, not in the laboratory.

Romualdo Moscioni: Santa Maria Maggiore, Barletta, albumin print, 39,2 x 26,4 cm (KHI, inv. no. 4201)

Fratelli Alinari: San Lorenzo Maggiore, Naples, before 1922, gelatine-silver print, 26,2 x 19,4 cm (KHI, inv. no. 65013)

Hilde Lotz-Bauer: Palazzo Davanzati, Florence, before 1943, print on barytpaper (KHI, inv. no. 378127)

Luigi Artini: Sant'Antimo, before 1978, print on barytpaper, 23,9 x 18 cm (KHI, inv. no. 347176)

Hilde Lotz-Bauer: Palazzo del Bargello, Florence, before 1940, print on barytpaper, 24,2 x 18 cm (KHI, inv. no. 378132)

Giorgio Laurati: Cathedral, Florence, print on barytpaper, 22,9 x 16,2 cm (KHI, inv. no. 576130)

Fritz Schmidt: Photografisches Fehlerbuch. Ein illustrierter Rathgeber für Anfänger und Liebhaber der Photographie, Karlsruhe 1895, p. 20

Fritz Schmidt: Photografisches Fehlerbuch. Ein illustrierter Rathgeber für Anfänger und Liebhaber der Photographie, Karlsruhe 1895, fig. 5

Roberto Sigismondi: Campanile of the cathedral, Cortona, 2013, print on R-C Paper, 23,5 x 17,7 cm (KHI, inv. no. 610713)

Luigi Artini: Palazzo Pubblico with Torre del Mangia, Siena, before 1983, print on barytpaper, 19 x 18 cm (KHI, inv. no. 413849)

Luigi Artini: Palazzo Pubblico mit Torre del Mangia, Siena, before 1983, print barytpaper, 19 x 18 cm (KHI, inv. no. 413850)

Photograph by Artini with corrections of linear distortions

© KHI in Florence | 19.09.2021 12:33:29