Technique used in computer graphics and photography to obtain an image in which the dynamic range (range of luminance between the lightest and darkest areas) is the broader possible. It has detail in the whole scale from white to black. No sensor can capture in a single shot the entire DR of a high-contrast subject (its exposure latitude is less) and often it is necessary to perform at least three bracketing shots, by varying the exposure time and fixing the other parameters. This will compensate the loss of detail in underexposed or overexposed zones in each image. Dedicated software process and merge the series of shots to make a single photo with the correct exposure at each point. If exaggerated, the photo seems fake, like a painting.
Published in Chapter:
Integrated Survey of “Quadrature” Aimed at the Graphical Analysis of Painted Perspective: Trompe l'Oeil Architecture, Palazzo Arese Borromeo
Donatella Bontempi (University of Parma, Italy) and Giorgia Bianchi (University of Parma, Italy)
Copyright: © 2017
|Pages: 35
DOI: 10.4018/978-1-5225-0680-5.ch016
Abstract
The issue of knowledge and documentation of cultural heritage is always central in the field of Drawing, which, through the survey, is always preliminary to the safeguarding and valorisation of artistic and architectural heritage. The paper aims at presenting some results of a survey realized following an approach that mix direct, laser and photographic techniques to obtain high quality ortophotos of the painted surfaces, useful to be the basis for the graphical analysis of the trompe l'oeil perspective. The phases are: survey campaign and data acquisition, postproduction of the RAW file, photo straightening, photo modelling, orthophoto output, CAD analysis, conclusive considerations. All these steps are referred to the experimentation on a concrete case study, one of the numerous frescoed rooms belonging to the rich iconography of Palazzo Arese Borromeo in Cesano Maderno (MB, Italy), a building that is an actual unicum in its kind.