The blue hour and the golden hour are the terms appended to the two phases of the rising sun and the sunset : before and after it's passage on the horizon. This essay intends to make crossover of this very special natural light, carrying a strong symbolism for man and in art, and its uptake by digital photosensitive surfaces. What are the issues of uptake and the representation of this physical light fast and total switchover in digital? As a first step, after precisely defining the phases of the golden blue hour and explained their causes, we seek to understand the symbolic significance of this light, which brings a dual psychological/physiological response in humans. Knowing this, how is this light used in the art of cinema, and for what symbolic? In a second step, we want to analyze this shift of light, from a geometrical, quantitatively and qualitatively point of view , based on measurements made during the practical part of the essay. This step is aimed at the profound knowledge of this light, and to identify key points to master fo its digital uptake. Thus, in the third part, we study in detail the characteristics of digital photosensitive surfaces, two in particular (Alexa Studio and the Blackmagic 4 K), to identify the understanding of important parameters, to master and especially to put in relation with the light of the golden blue hour, to succesfully manage its quantity and quality, and to highlight the importance of the adaptation of our uptake strategy of this physical changeover of light depending on our camera.
Keywords : Golden Hour / Blue Hour / Magic Hour / Sun / Digital / Raw / Contrast / Colour / Exposure / Sensor / Sensibility