In this episode of On Lightness, I have the pleasure of speaking with the visionary photographer Michael Wesely. We talk about his breathtaking year-long exposure photographs, how he became the godfather of this unique art form, and how his work reshapes our perception of time, space, and the built environment around us. It was a refreshing change to explore lightness through the lens of a photographer, expanding the field of this podcast into new territory.

This episode was moderated and produced by Leon Hidalgo.

The following article is meant as an informational extension of the podcast episode:

Michael graduated from his photography studies in Munich with a curiosity for the state of his discipline. Early on, he began to question the often aggressive act of image-making — the idea that a photographer takes or even grabs a picture. He rejected this notion and from this resistance, a new method slowly crystallized — one that would define his artistic journey: the technique of Ultra-long Exposure Photography.

Beginning with his five-minute portraits, Michael found a way to let the subjects create their own images.

Lightness¹ the quality of having little weight

Michael thinks lightweight structures barely exist in the contemporary architecture of Germany today. With his connection to South America he learned to appreciate the lighter and simplistic way of building - especially in Brasil, where he often traveled to.

A Camera, he says, is a room, even in our phones there is this small dark room. In his early explorations he played with the composition of this space, which ultimately led him to his famous technique.

He associates weight not just with physical mass but with effort and time. A long exposure, spanning five years, may result in an image of the same size as one taken in a millisecond, yet its weight is greater. It carries the gravity of duration.

Today, technology allows Michael to travel much lighter, which he welcomes with a certain relief. It took him 10 years to implement his whole process from analogue into the digital photography realm.

lightness² the state of being light in color or shade

Light, to Michael, is everything. Photography, he reminds us, is born of light, time, and space. If one pays close attention, the performance of natural light throughout the day can be more exciting than any cinema, and it’s free. Light reveals thing, a certain sunlight glancing off a brick wall can reveal the quality of craftsmanship.

If Michael’s photography were an architecture, it would be one that catches and tracks the sunlight throughout the day, a building that collaborates with the rhythms of the sun. Something closer to indigenous architecture, built with precise knowledge of the local natural conditions.

lightness³ being carefree or feeling without burden

For Michael, time is always relative. Its scale depends on perception, on how each of us forming our own reality of the world. What interests him most is the space between the visible and the invisible, the ambiguity in which imagination begins. That tension has always been central to his work.

He’s fascinated by how time changes spaces, by the physical traces of the past that often go unnoticed. Remembering them, he says, helps us see how lucky we are to sharing the present moment.

In one recent project, Michael played with the architectural scale of 1:100, but instead of using it to describe space, he imagined it as a measure of time. Thinking about how a place or a design might appear in a hundred years, he believes, is a valuable exercise not only for photographers but also for architects.

This way of thinking, projecting time forward and backward, also defined a turning point in his own life. When Michael decided to create his first one-year exposure, he couldn’t know what would come of it. Looking back, that experiment became a foundation for everything that followed.

In this episode of “On Lightness” I am having a conversation with membrane and cable engineer Dr. Rosemarie Wagner. We are talking about her way into the world of lightweight engineering, favorite structures and what she learned from being a professor in the architectural field for several decades now. I felt inspired like many of her students by Dr. Wagners motivation for and work in the field of lightness.

This episode was moderated and produced by Leon Hidalgo.

The following article is meant as an informational extension of the podcast episode:

After graduating from the University of Stuttgart, Rosemarie Wagner joined her father’s engineering firm but quickly realized the conventional work bored her compares to the lightweight structures she’d studied under pioneering professor Jörg Schlaich. She moved to Schlaich’s Institute of Lightweight Structures to research suspension bridge history, gaining access to his presentation archives that deepened her fascination with the force-shaped structures. A year later, Schlaich offered her a PhD position combining cable-net structures with concrete slabs—research that would underpin numerous bridges built by his firm SBP around Stuttgart.

After completing her PhD, Wagner joined a cross-institute research group that included the Institute for Air and Space of the University of Stuttgart, where colleagues had just built the first solar-powered airship and needed a hangar. Taking part in a student group, she did the structural engineering for a helium-filled hangar called HELION: The first building to hang from the earth rather than stand on it. The structure was destroyed by a thunderstorm after just a few months when the low-budget foil proved non-UV-resistant.

Festo is one of the biggest pneumatics companies in the world. Rosemarie was now asked to work there, designing and engineering a building that most people in the industry said could not be done. Everyone except Jörg Schlaich: the Airtecture Hall of Festo GmbH Co. KG.

Once again, life intervened with a phone call—this time offering a position at the architecture department of Munich’s University of Applied Sciences. Teaching came naturally, and she quickly recognized its importance. What became essential was giving students a feel for forces through physical models and strengthening their appreciation for equilibrium-shaped structures. After Frei Otto, numerous poorly executed copies of these structures had failed, leading to widespread disapproval that Rosemarie felt could only be reversed through education.

Lightness¹ the quality of having little weight

While floors are inherently difficult to make lightweight, Rosemarie argues that having thermal mass does not require building massive buildings. The Multihalle Mannheim exemplifies this: its ultralight roof pairs with a concrete walkway that provides the necessary thermal regulation.

When asked about her favorite structures, she offered an intriguing list of buildings: The Aviary of “Peacock Island” in Berlin, St-Lukas-Church in Bremen, The Meilenwerk in Düsseldorf, The Washington-Dulles Airport in Virginia and Lowara Office Building by Renzo Piano in Vicenza.

lightness² the state of being light in color or shade

Rosemarie believes light is an architect’s concern and beauty cannot be planned, yet certain light moments remain with her. One was visiting Yale’s Beinecke Library with its remarkably thin marble walls—reminiscent of Franz Füeg’s Pius Church in Switzerland.

Like the thin slices of marble in the wall, single-layered membranes are also translucent, creating a beautiful light atmosphere that can only be observed from the opposite side of the light source.

lightness³ being carefree or feeling without burden

For Rosemarie, true lightness emerges when clients embrace a building and care for it because of how it makes them feel. She believes we focus too heavily on visual information, forgetting we are multisensory beings. Other moments of lightness, she says, come from touching fabrics like the silk wall hangings at Ludwigsburg Palace, or watching the sunset over Munich’s Olympic Park—experiences that remind her architecture is as much about sensation as structure.

Throughout her life, she has never hesitated to jump into cold water. That same fearlessness, she believes, should drive architects to be braver and engage in more open exchanges about how buildings can be constructed. Through repetition—trying, failing, and trying again—true learning happens. Ultimately, in her unique mindset Rosemarie Wagner hopes to leave traces in both buildings and people.

In this episode of “On Lightness” I am having a conversation with architect and industrial designer Christian Borger (aka @see_borg). We are talking about what lightness means to him, how he stumbled into becoming a furniture designer and how ultimately working with his hands is his ideal state of being. I found this conversation deeply inspiring and felt like we found a lot of common ground on that sunny day in front of the Metropolitan Opera House in Manhattan.

This episode was moderated and produced by Leon Hidalgo.

The following article is meant as an informational extension of the podcast episode:

Christian enjoys creating and working with his hands, even when an idea is still in its early stages. In his first rented studio, limited finances restricted the range of tools and materials available to him—constraints that ultimately shaped and defined his design language.

Beginning at the scale of model making, he discovered a successful foundation in a three-dimensional grid structure with diagonal tensioning elements. This modular framework became the basis for a variety of furniture pieces.

A pivotal moment came with the creation of his second chair, aka The Breakthrough Chair. It was through this piece that he fully grasped the flexibility and multifunctionality of the grid-based system.

Lightness¹ the quality of having little weight

Recognizing that surfaces accounted for much of the weight in his furniture designs, he began experimenting with stretched fabrics, drawing inspiration from traditional Skin-on-Frame Canoes used in Canada.

However, these "skins" lacked the rigidity required for seating or table surfaces, and high-tech solutions like honeycomb aluminum or carbon fiber were not financially viable. This and his ethos of working with simple means led Christian to stick with more accessible materials like 6mm birch plywood or polycarbonate.

Combining these with the wood-lattice structure and the carbon fiber bracing has been the composition of many pieces of furniture like this table for six people weighing only 4 kg (8 pounds).

lightness² the state of being light in color or shade

On the other hand, both the skins and the polycarbonate work beautifully as modifiers of the light conditions, becoming a filter and projection surface for the skeletal character of his creations.

lightness³ being carefree or feeling without burden

As much as he likes finishing projects, his true passion lies in the process. Re-imagining objects, reflecting and documenting while intensely prototyping seems to be a state most natural to Christian. This was particularly true in his recent flatware products, which he noted was the first production he truly completed.

Attaching a price to something so personal carries a strange emotional weight because much of the value in his work comes from the passionate research and prototyping that precedes the final product. As he puts it, “The process is everything.”

In a world saturated with low-quality, mass-produced goods, Christian hopes his work inspires greater appreciation for craftsmanship. Should his side project ever evolve into a full-time profession, he’s committed to preserving the same level of intensity and respect for handmade work.

In this episode of “On Lightness” I am talking to Nicolas Dorval-Bory, who was recently announced Director of the ENSA Versailles Architecture School. He is based in Paris, where we met in his architecture office to talk about lightness. He challenged a lot of views I had, which was very enjoyable.

This episode was moderated and produced by Leon Hidalgo.

The following article is meant as an informational extension of the podcast episode:

Lightness¹ the quality of having little weight

Contemplating the fatness of our built environment, Nicolas compared it to a heavy boat, that in the ocean of extreme future weathers, will be harder to topple. Meaning, we need some heavyness for resilience, but in a balanced system combined with lightness -much like the relationship between the heavy fireplace and the light facade of the mentioned David Ogden House.

Asked about a project where revealing forces played a role, Nicolas mentioned the Kooperative Großstadt Project, where gravity played a big role in establishing a superposition of structural systems getting lighter with added floors.

One of the early projects, called “Paysage en Exil” was an homage to the Blur Building by Diller Scofidio, as well as to the work of known architects Lacaton & Vassal and Gardener Gilles Clément.

Nicolas states that the apparent lightness of this project, much like in the Environmental Bubble of Rayner Banham, is opposed by an invisible heaviness of technological infrastructure and energy intensive material use.

lightness² the state of being light in color or shade

Asking Nicolas about light, he quickly stated that light is a term, that is too general for such a complex topic, and that specifying and deepening knowledge of certain aspects of the electromagnetic spectrum is a first step to revealing and working with the beauty of it.

lightness³ being carefree or feeling without burden

As a hobby astrologer, Nicolas enjoys looking at the sky. It gives him a feeling of lightness. Like any feeling of lightness, he states, it comes with a strong counter-feeling of heaviness—in this case, the unimaginable mass of the universe.

Although never visiting the Blur building, it has become a turning point for Nicolas in architecture, as it showed the possibility of turning a climatic condition (one that reminded him of his childhood) into a tangible structure, which opened a whole new world. This immaterial world was further expanded during the years working as a teaching assistant for Philippe Rahm.

Ultimately, Nicolas thinks that working as an architect and as a professor is not too different. In both professions, undertaking research in a group constellation is the foundation for any project.

In this episode of “On Lightness” I am talking to Dr. Christoph Gengnagel, who is both partner at Bollinger+Grohmann Engineers and professor and researcher at the architecture and urbanism department of the UdK Berlin. We talk about the beauty of lightness, how it can be researched and how it can be really hard to implement it as a construction practitioner.

This episode was moderated and produced by Leon Hidalgo.

The following article is meant as an informational extension of the podcast episode:

Christoph Gengnagel studied Civil Engineering in Weimar and later Architecture at the Technical University in Munich, where he discovered the beauty of lightweight structures. His doctoral dissertation is a thorough work on mobile membrane structures, which included a mobile grandstand that he worked on as part of a collaboration between the Technical University Munich, LSU of the University of Dundee and ARENA Ltd.

Following this work, through different research projects, he attempted to bridge the gap between research and real world applications but soon came to the realization that purely lightweight structures are hard to implement. One of these efforts was the Hybrid Tower / CITA, an active-bending structure. This was a collaboration between his chair KET at UdK and CITA at The Royal Danish Academy of Fine Arts, as well as A. Ferreira & Filhos

Although a lot of us admire both natural and nomadic structures and see them as prime examples of the beauty of lightness, Christoph understood that to serve all the complex functions of city living nowadays, he had to adjust his ideology of designing lightness to one of geometry-based weight reduction in existing systems. A more pragmatic approach was needed to actually help the building transition.

The properties of light were never a big factor in his work, although he thinks it should play a bigger role in architecture and engineering education. Remembering the reflection of light in caves, experienced as a kid, is a quality that's hardly met by any of his built projects, he says. Stating that only some artists were able to work with light in a truly admirable way, partly because they don't abide by building norms which counteract beauty.

Finally, we talked about Dr. Gengnagels' current research on reducing mass in ceiling systems,

about his passion for cycling as a means of feeling lightness.

and about the one time he felt a built work was embodying lightness. On the construction site of the Bauhaus Archive Tower in Berlin.

In this episode, I am talking to Dr. Prof. Thomas Speck about the meaning of lightness in the field of biology, exploring topics like the material efficiency of nature, biomimicry, half-timbered houses, Frei Otto, and the many projects Dr. Speck did in collaboration with Jan Knippers and Achim Menges from the IntCDC Cluster at the University of Stuttgart.

This episode was moderated and produced by Leon Hidalgo.

The following article is meant as an informational extension of the podcast episode:

Where it all started: An interest in the Bioacoustics of frogs

The Limited Materials of Plants: Cellulose, Lignin, Hemi-Cellulose and Pektins

The referred ingenious “Fachwerkhaus” or in english: Half-timbered House

Frei Otto was a Skeptic of biomimicry, although his structure's form-finding was often inspired by natural principles.

mentioned livMatS Pavilion, 2021, a collaboration between Clusters of Excellence: IntCDC and livMatS as well as Fibr GmbH

And the light pattern it creates.

The mentioned reactive shading system inspired by pine cones: Solar Gate, 2023, Stuttgart. A collaboration of ICD, intCDC, livMatS, IKT.

The mentioned Project: FlectoLine Facade, 2024, Stuttgart, a collaboration of Clusters of Excellence: IntCDC and livMatS as well as ASCA GmbH. Inspired by the trap mechanism of the waterwheel plants (Aldrovanda vesiculosa)

In the end let's get an idea of the places, that evoked an existential feeling of lightness for Dr. Speck: The first fieldwork in an undisturbed tropical rainforest.

and standing in the nothingness of snowy Spitzbergen