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Guerra, Monti, Miniutti 
The reading of a photographic map is more complex because it wasn’t done any selection on datas and informations. The whole datas 
of the original photos are displayed on the photographic map with a precious added value: the metricity. In fact on the map is 
possible to measure objects, in opposition to common photos. Every cartography must have the correspondance beetween territory 
and his representation. 
Photography, which is the most mimetic form of representation, has a contraddiction: it is easy to be read but hard to be interpreted: 
This difficult is connected to the big quantity of datas, their intersection and to the lack of any structuration in passing from datas to 
information. 
Maybe it is just this caotic wealth, the big documentary value of photography. The documentary value is not given from the 
presumed objectivity of the image, guaranteed from his mechanic nature, but from big quantity of datas that the camera is able to 
record. 
Photoplans born with the purpose to be in the same time instrument of documentation, interpretation and transformation of the cities. 
They are not only photos but charts too: in this way it’s possible to exceed images, which are the main source of thematic 
information, and to obtain even quantitative informations. 
Besides offering a “photo-reading” of a city, showing in detail and evidence the typologic texture, the physic thickness and the 
conservation of its urban texture, photoplans give informations about objects’s position and dimension: transformations can be 
located and measured. 
3. THE 1982’S PHOTOPLAN 
The CD-ROM is the digital version of the 1982 photoplan in 1:500 scale published by Marsilio Editori in 1985 with the title 
“Venezia forma Urbis” and also reduced to 1:1000 scale and placed side by side to vectorial cartography in “Atlante di Venezia” 
(1989). It’s opportune to remember some informations on the creation of this foundamental cartography describing the forma urbis of 
Venice in 25 may 1982, the day of the aerial photos. 
The photoplan, realized by the Compagnia Generale Riprese aeree di Parma, is a part of a complex cartographic system of the Venice 
Town Council which includes also numeric cartography in 1:500 scale for all the historic settlements (1:2000 scale for the others) 
and the photoplan (only black and white) for the coastal and agricultural areas. 
Fig. 1 : Union table of 1982’s photoplan 
The photoplan’s scale is correct only on the ground level and it grows for all those points higher than this level. The mosaic of two 
sheets of the photoplan is correctly possible only on the ground level. In this way there will be some errors on the buildings which are 
shown on the borders of two or more sheets, so it’s not possible to have a correct composition of their total image. 
This fact, considered by many people an error, is a consequence of the map’s geometry and it doesn’t take away the documentary 
importance of the photoplan. 
The tool “unione quadri" (i.e. sheets mosaic) in the photoplane’s navigation software shows this kind of problem; the union of the 
sheets occurs using planimetric cartographic coordinates and everything that isn’t on the ground level is inevitably out of scale.