The lighting project for the Polyptych of San Martino, a late Gothic Lombard masterpiece produced by Bernardo Zenale and Bernardino Butinone between 1485 and 1505, located in the Basilica of San Martino in Treviglio (Bergamo, Italy), has been meticulously designed by Studio Switch and illuminated with solutions by Linea Light Group.

The project to illuminate the polyptych, launched by the Parish of San Martino, had been previously proposed by Studio Switch in June 2019, and subsequently approved by the Commission for Religious Works of Art of the Curia in Milan in December 2019. All the parties involved, however, agreed to put the authorisation process on hold whilst waiting for the decision by the Parish to move the Polyptych to a more suitable site to enable it to be better preserved and showcased.

The new site selected was the former Church of San Giuseppe ai Pellegrini, referred to as the ‘Polyptych Room’ within the overall project, which also includes the lighting design.The advanced technical solutions provided by the Linea Light Group successfully addressed all the requirements outlined by Studio Switch. The lighting system for the Polyptych Room features two lines of projector spotlights. The ‘first line’ is integrated and discretely concealed within the base structure (bollard light) to illuminate the lower half of the work, while the ‘second line’ illuminates the upper half, powered by a single track housed on the central chain of the 6.6 metre high room. The bollard light – originally installed as a ‘safety system’ for the work – also proved to be an ideal place in which to house the lamp bodies, i.e. 3 Pound Shaper profilers and 6 Pound projector spotlights with a diffused filter.

The solutions housed inside the structure, however, did not have sufficient power to illuminate the entire work – from bottom to top – so for the illumination of the upper part of the panels, it was decided to create a ‘second line’ and to work on a tie-rod placed at a height of 6.5 metres. The solutions of 7 Pound Shaper profilers and 4 Pound projector spotlights fitted with a diffused filter, were, in fact, laid out on a three-phase track fixed on the tie-rod. The DALI-controlled bodies work at an ‘irregular’ angle of incidence, resulting in a blend of profiled and diffused light.

Paolo De Bellis and Stefano Bragonzi, the co-founders of Studio Switch, described the issues that they had to tackle as follows: “The project met with a series of challenges due to the architectural constraints and predominance of gold shades in the work which needed to be enhanced while maintaining the balance with the other colours. Given the size of the Polyptych, successfully adjusting to the reduced distance between the possible positions of the spotlights and the object to be illuminated was perhaps the greatest challenge of all.  Dealing with these constraints by identifying the most suitable devices proved to be complex. The solution was to choose lighting fixtures that helped to tell the story through the use of mixed profiled and diffused lighting.

Ten Pound Shaper profilers, seven installed above and three below, and ten spotlight projectors with Pound diffused optics, four above and six below, illuminate the Polyptych, each with an adjustable beam opening to control the distribution of light and comply with the regulation standards. The warm white light source selected with a colour temperature of 3000 K and a 98 CRI ensure an excellent colour rendering with a colour deviation of 2 SdCM. The circular pendant light initially installed in the first room, preceding the one with the Polyptych, to provide general lighting, was eliminated. A combination of displaced spotlights was instead chosen to minimise glare.

The cylindrical Pound_BS projector spotlights with a base plate, positioned at a height of 6.6 metres on the four corner capitals of the pillars, efficiently illuminate the space and are discretely concealed from sight. The light distribution is accurately balanced, delivering about 100 lx for the vault and 75 lx for the floor, with lower values (about 30 lx) on the walls to create graduating light between the rooms without interfering with the layout envisaged.

The entire system is controlled by the DALI protocol, offering flexibility to adapt to various requirements.

The Polyptych Room is divided in two by a central arch which, although a single structure, clearly showcases the two different settings, thanks to the contribution of the lighting solutions adopted. On one side, you have the actual Polyptych and on the other side, a preceding area. With the audio/video systems turned off, this area welcomes visitors with the wide beam Pound projector spotlights, creating indirect diffused light on the vault for the ambient effect, and spotlights with a narrower beam directed at the desk, all combined with the lighting of the Polyptych dimmed by 10%. When the actual visit starts, the above-mentioned audio/video system then engages visitors in an immersive and exciting experience for interactive enjoyment of the work. The different on-off cycles of the light controlled by DALI, combined with projections and the narrative, metaphorically capture the scene, given that the lights in the area before the Polyptych are turned off.

Studio Switch’s lighting project also involved other key areas that make up the entire exhibition space of “The Doorway to Heaven”: a genuine exhibition route that includes the ‘Sala dei Confratelli’ and the Aquilonare Sacristy, as well as the Basilica of San Martino in all its splendour and the above-mentioned Polyptych Room. As you come out of the Polyptych Room, a corridor with a beamed ceiling, stunningly lit by the slimline cable system of Ink System lights, leads you to the unexpected and surprising Aquilonare Sacristy, while Pound_BS spotlights with a base plate lead you up the staircase to the Sala dei Confratelli. This room has been laid out to display exquisite statues and groups of sculptures made of wood and terracotta. In the corners of the room, Joshua adjustable floor lamps with indirect light add to the overall lighting while the light pointing on the works is provided by Pound Focus spotlights with adjustable optics, installed on customised tracks to fit seamlessly in with the irregular ceiling beams. The angles chosen for the light beams deliberately accentuate only one side of the works, while the other ‘basks’ in indirect light, for three-dimensional illumination that deliberately differs depending on whether visitors are entering or leaving the hall.

Even the Aquilonare Sacristy below – in which elegant ancient bishop’s robes are showcased – features the use of Pound Focus projector spotlights, arranged in a evenly staggered pattern (a line of three projectors every two beams): the central projector is always directed on the walkway, while the two side projectors illuminate the elaborate cupboards, highlighting their splendid wooden inlays.

The successful integration of advanced lighting solutions not only highlights the grandeur of the Polyptych and the various exhibition rooms, but also contributes towards creating a dynamic and engaging viewing experience for visitors.

Studio Switch, in partnership with Linea Light Group, has achieved a harmonious balance between tradition and innovation, thus ensuring the preservation and enhancement of these historical masterpieces for future generations.

Credits:

Lighting designer: Studio Switch

Products: Pound Shaper, Pound track, Pound Focus, Pound BS, INK System, Joshua

Photos: Andrea Martiradonna

Year: 2023/2024

Linea Light Group