S. Martino Cathedral
Magenta, Milan, Italy
Lighting Project: Arch. Jacopo Acciaro

Lighting project for the Basilica of San Martino, Magenta, Milan. By Jacopo Acciaro. Lighting project: Arch. Jacopo Acciaro. Restoration manager and coordinator of works: Arch. Ernesto Puricelli. Technical supply coordinator and technical consultant for Targetti products: Arch. Giacomo Zadro. Installation of electrical system and fixtures: VIMI Impianti, Magenta. The lighting project for the Basilica of San Martino in Magenta, one of the largest basilicas in Lombardy, is part of a vast restoration initiative aimed at requalifying the architectural area and returning the numerous paintings lining the walls of the Basilica to their former glory. This is a very impressive and atmospheric place of worship. Situated in the center of the old town of Magenta, it is rich in design concepts as well as being very complex from an architectural viewpoint. With the full support of Architect Ernesto Puricelli, in charge of restoration activities and coordinator of all the relevant works, the project was based on an awareness of the important role played by lighting in the maximization of the restoration work as well as the correct perception of existing architectural volumes. In my opinion, the lighting project of a place of worship should start with certain unavoidable premises (correct illumination values, controlled luminance, architectural décor) which support all the initial project theories, guaranteeing a result that is coherent with the subject in question. The approach adopted for the lighting project of the Basilica of San Martino was based on these very premises, without losing sight of the main uses of a Church: the celebration of liturgical functions and providing space for personal prayer. Moreover, the layout of the Basilica (Latin Cross) and the presence of architectural features (side chapels, various altars, baptistery, organ, etc.) as well as wall paintings (Stations of the Cross), sculptures (St. Francis, Madonna of the Rosary) and frescoes, demanded a careful analysis of the different “visual functions” present inside the Basilica itself. All these premises led to the idea of creating relationships between the different values of illumination (lux) selected for the various areas, surfaces and “visual functions” (Altar, Ambo, Vaults, sculptures, walking surfaces, reading light, wall paintings, etc.), paying particular attention to the positioning of the fixtures in order to avoid unpleasant glare, providing separate on/off switches to satisfy different functions as well as lighting décor effects. I tried to combine these design themes, which are often very technical and difficult to understand, with the concept of Light as one of the elements that decisively influence our perception of space. Light rests on objects and surfaces, determining their appearance and thus modifying the same; dark is an opposite element which “prevents” vision and it is thanks to the balance between these two elements that we are able to perceive. This concept is palpable in the lighting project for the Basilica of San Martino. The decision to accurately and precisely illuminate all the elements present has determined an overall vision which is rich in light and shade effects, where illuminated volumes and areas which have deliberately been left in shadow live together in harmony, establishing atmospheric and targeted visual hierarchies. The perception of the space in the eyes of the congregation has changed, displaying architectural and decorative features which were previously neglected or little emphasized. In fact, the previous solution, which consisted of fixtures fitted with 400W/1000W metal halide lamps with diffusing optics positioned on the vault of the central nave, offered greatly dispersed general lighting with very high illumination values which were excessive for a place of worship. This had a flattening effect on the architectural volumes accompanied by a poor color rendering of the decorations caused by a very high color temperature (K) and an incomplete spectral composition of the sources used. Another objective which has been persistently pursued is the diminishment of direct luminance which, thanks to the use of alveolar screens and adjustable fins positioned on the fixtures, ensures excellent visual comfort for the congregation as well as the person conducting the various functions, unlike the previous solution. In order to satisfy and resolve the problems described above, a series of fixtures and relevant accessories was required which could guarantee high performance in terms of lighting design and appearance (to be as little invasive as possible). After a careful onsite inspection, the choice was made to use fixtures produced by Targetti Spa which, with the assistance of Architect Giacomo Zadro, was able to supply materials that perfectly complied with the characteristics required by the project. We tried to use fixtures which were as compact as possible, where different optics (5°,15°,30°) could be placed in the same reflector combined with lamps of different wattages. “Trail” fixtures, for CDM Mastercolour 3000K metal halide discharge lamps with high color rendering, and “Foho” fixtures for halogen lamps with incorporated reflectors (dichroic and AR111), together with their many accessories, perfectly suited our requirements. After defining the concept and choosing the types of fixtures, the project entered the final phase which involved the studying of positions, the assessment of wattages and the selection of various accessories. The following results were obtained: - “Trail” fixtures were chosen for lighting the walking surface in the central nave, the transept and around the high altar (Apse area), positioned on the cornice, h. 18 m, with a 30° aperture for 150W CDM Mastercolour metal halide lamps with high color rendering and illumination values of between 110 lux/150 lux; a very controlled and precise light positioned near the required area without lighting vertical surfaces, thus fully satisfying the “visual functions” of reading and praying, ensuring moderate luminance thanks to the use of anti-glare screens and adjustable fins; - “Trail” fixtures were used to light the walking surface of the side aisles, positioned on the capital, h. 8 m, with 30° aperture for 35W CDM Mastercolour metal halide lamps, with high color rendering and illumination values of around 60 lux/80 lux (deliberately lower than the central nave); a very controlled and precise light positioned near the required area in order to gently illuminate the initial part of the vertical surfaces, thus fully satisfying the “visual function” of prayer, ensuring moderate luminance thanks to the use of anti-glare screens; - “Foho” fixtures were chosen for lighting all the vaults (side aisles, side chapels), and positioned on the four capitals, using 50W 60° 12V dichroic halogen lamps with maximum color rendering. Particular attention was paid to the uniform distribution of light on the vaults, leaving the ribs separating each vault in shadow in order to increase the perception of the volumes; - The vaults of the central nave, transept and apse were illuminated using “Armilla” fixtures for 300W linear halogen lamps with maximum color rendering, positioned on the cornice, h. 18 m. Halogen lamps were chosen because the same color rendering was required for all the vaults in the Basilica, - “Foho” fixtures, positioned on the capitals, were chosen for lighting the wall paintings (Stations of the Cross) on the vertical surfaces of the side aisles, using 50W 38° 12V dichroic halogen lamps with maximum color rendering and estimated values of 150 lux/190 lux, paying particular attention to the angles of reflected light, with direct luminance controlled by adjustable fins (elette = alette?); - “Foho” fixtures, positioned on the capitals, were chosen for lighting the sculptures of saints at the beginning of the side aisles, using 50W 10° 12V dichroic halogen lamps with maximum color rendering and estimated values of 200 lux/25 0lux, with direct luminance controlled by adjustable fins (elette = alette?); - Foho” fixtures, positioned on the capitals, were used to light the altars in the side chapels using AR111 100W 24° 12V halogen lamps with maximum color rendering and estimated values of 250 lux/290 lux, with the direct luminance controlled by adjustable fins (elette = alette?); -4 “Trail” fixtures were chosen to light the altar, positioned on the drum of the dome, h. 23 m, aperture 15°/5°, using 150W CDM Mastercolour metal halide lamps with high color rendering and estimated illumination values of around 350 lux/500 lux; a very controlled and precise light positioned near the required area, an inexistent luminance for the congregation since the fixtures are invisible from the central nave; - “Trail” fixtures were chosen for lighting certain details such as the Ambo (Anbone = Ambone), Crucifix and Baptistery, positioned on the cornice, h. 18, 5°, using 70W CDM Mastercolour metal halide lamps with high color rendering and estimated illumination values of around 200 lux/300 lux; a very controlled and precise light positioned near the required area, with the direct luminance controlled by adjustable fins (elette = alette?); - The organ in the central nave was illuminated by “Trail” fixtures, positioned on the cornice, h. 18 m, aperture 30°, using 70W CDM Mastercolour metal halide lamps with high color rendering; a very controlled and precise light positioned near the required area without illuminating the vertical surfaces, ensuring modest luminance thanks to the use of anti-glare screens and adjustable fins. Particular attention was paid to training the fixtures in such a way as to avoid illuminating the entrance in order to give the impression that the organ is suspended and unsupported; - For lighting the High Altar, “Trail” fixtures were chosen, positioned on the cornice, h. 18 m, 15°, using 150W CDM Mastercolour metal halide lamps with high color rendering and estimated illumination values of around 350 lux/500 lux; a very controlled and precise light positioned near the required area, with modest luminance thanks to the use of anti-glare screens and adjustable fins, - “Foho” fixtures, placed on the capitals, were chosen to light the four Evangelists positioned beneath the drum of the dome, using AR111 100W 10° 12V halogen lamps, with maximum color rendering, and “Foho” fixtures with 50W 60° dichroic halogen lamps and direct luminance controlled by adjustable fins (elette = alette?); the beams of the AR111 lamps were adjusted to intersect with each other in order to obtain accent lighting, - “Armilla” fixtures, positioned on the cornice, were chosen to illuminate the dome using 300W linear halogen lamps with maximum color rendering; halogen lamps were chosen in order to obtain the same color rendering for all the vaults in the Basilica.