The research project “Tent – Photographic latency in Kepler’s camera” aims to design and build a vertical camera obscura, an optical and photographic device that allows to see and photograph the stars in the sky (at night). This device is inspired by the tent-camera described by the early 17th-century astronomer Johannes Kepler, of which a 19th-century model built by Charles Chevallier (1804 – 1859), kept at the Museu da Ciência da Universidade de Coimbra, was analysed.
Based on Kepler’s work, it can be assumed that he used a camera obscura to draw the stars and thus represent the chart of the heavens. However, no specimen of this hypothetical version has survived to the present day, and most existing tented camera obscuras are adapted for landscape drawing.
In this research project, we try to reconstruct a version of the vertical camera obscura for astronomical observation, with the double purpose of educational dissemination and use in artistic and photographic research projects.
During the course of the project, preliminary models were tested at the Osso Cultural Association, at the 2022 finalists exhibition at the Escola Superior de Artes e Design de Caldas da Rainha and at the Astronomy Park of the Centro de Ciência Viva de Constância. The tests performed so far allowed addressing technical issues related to the optical and structural properties of this device, namely regarding its portability, wind stability and ability to allow the projection of the stars at night with enough intensity for its visualization and photographic record.
Tests have shown that it is possible to see stars projected onto a sheet of paper using only the image projected by a simple plano-convex lens and that these bright points can be captured photographically using paper or low-sensitivity photographic emulsions.
The development of the tent-camera was adapted to an artistic and pedagogical use, trying to reconcile the possibility of drawing the projected image, making photographic records without using other equipment or just seeing the projected stars in small groups, encouraging discussion and sharing about what is being observed.
In the scope of the exploration of the artistic and pedagogical potential of this device, long exposure photography sessions during the night and cloud drawings in the day sky have been carried out so far.
The project results from a collaboration between LiDA, the Research Unit Glass and Ceramics for the Arts (VICARTE) of the Faculty of Sciences and Technology of the New University of Lisbon, the Research and Study Centre in Fine Arts (CIEBA/FBAUL) of the University of Lisbon and the Associate Laboratory for Green Chemistry – Clean Technologies and Processes (REQUIMTE).