Apparatus for the production of orthophotoplans

Claim 1

Apparatus for producing orthophotoplans comprising: an optical projection device for a stereoscopic pair of photographs of the subject, comprising two projection centers, a support, adapted to bear a sensitive surface, means for adjusting the distance from the support to the projection device, a receiving device for images of the portions of the photographs corresponding to a same portion of the subject, which receiving device is situated in the vicinity of the support, between the latter and the projection device, and is adapted to be moved with the support, an exposure device for successive adjacent zones of the sensitive surface, comprising an aperture provided in the receiving device, wherein the receiving device comprises two distinct visible marks, separated from one another in a direction parallel to the line joining the projection centers, the midpoints of the marks being aligned parallel to the projection centers, one of said marks being constituted by said aperture, the separation of the projection centers, for a given enlargement is equal to a distance, depending on the conditions of recording the photographs, increased by the separation of the marks and optical means, with two sighting axes and separation means for said optical means controlled by the separation of said marks, enabling, a stereoscopic reconstitution of one space mark and of a portion of the subject, whereby, at the moment when the observer produces coincidence between said one space mark and said portion of the subject, the projected images coincide with said respective marks and are hence separate, due to which, the sensitive surface is only printed by the image coincident with said aperture.