The Cleanroom and the Darkroom
On making things with your hands, and why experimental science and analogue photography are the same practice
A few weeks ago, in the mountains above Trento, someone I'd met briefly at an event in London pulled me aside between sessions. “I've been thinking about what you said at NPL,” he told me. “About the darkroom. About how it's the same thing.” He's a metrologist — his world is standards, uncertainty budgets, the kind of rigour that makes the kilogram what it is. Not someone you'd expect to be moved by a conversation about art. But something in that panel discussion had landed, and it had stayed with him for months.
I keep having versions of this conversation. At the National Physical Laboratory last November, I sat on a panel called Quantum meets creativity: art, music and the quantum imagination — the last session of a day otherwise filled with talks on SI units, quantum sensing, and national measurement infrastructure. I was there as a quantum physicist who also happens to spend a significant part of his life in a darkroom, working with silver halide emulsions, nineteenth-century chemistry, and light. The other panellists were Ruth Jarmen and Joseph Gerhardt of Semiconductor Films, artists whose work engages directly with scientific data and natural phenomena. Ilana Wisby moderated. The room was still full at 5pm, which in conference terms is a minor miracle.
What I said — what I keep trying to articulate, and what this essay is my attempt to finally write down properly — is that the creative practice I have in the darkroom and the experimental practice I was trained in as a physicist are not analogous. They are not metaphors for each other. They are the same thing.
Hands
I trained as an experimental physicist working with superconducting circuits. For years, my daily life involved cleanroom fabrication: depositing thin films of aluminium and niobium, patterning Josephson junctions through electron-beam lithography, etching, oxidising, measuring. You learn the materials with your hands. You develop an intuition for how a particular evaporator behaves on a Tuesday afternoon when the humidity is high. You learn to read the colour of a thin film by eye and know, before any measurement, whether the deposition went well. There is a vast amount of tacit knowledge in experimental physics that never makes it into papers. It lives in your fingers, your peripheral vision, the way you hold a sample.
This is the part of science that non-scientists rarely hear about. The public narrative is all theory, equations, breakthroughs — the clean, cerebral version. But the practice of experimental physics is craft. It is manual, iterative, and deeply physical. You are wrestling with matter, trying to coax it into doing something it doesn't naturally want to do. You fail far more often than you succeed. And the moments of success are not always explainable in the language of the paper you eventually write. Sometimes a fabrication run works because you varied something you weren't tracking, and your body knew before your mind did.
As my career progressed — as happens in science — I moved from the bench to management. I lead a research team now, working on quantum computing hardware at VTT in Finland. It is good, important work, and I believe in it. But I am no longer the one in the cleanroom. I am no longer the one with my hands on the materials. And I felt that loss acutely, in a way that surprised me.
The darkroom filled the gap. Not as a hobby, not as relaxation — as a practice. The same practice, transplanted into a different medium.
Lith
Let me explain what I mean by getting specific. Lith printing is a darkroom technique where you massively overexpose a sheet of photographic paper and then develop it in heavily diluted lith developer. At normal concentrations, the developer would produce an ordinary black-and-white print. But at extreme dilutions — sometimes 1:30 or beyond — the chemistry behaves differently. Development is sluggish at first. Then it undergoes what's called infectious development: once a critical density of silver is reduced in the highlights, the process accelerates dramatically and non-linearly. The shadows race to catch up. You have a window of seconds to snatch the print from the developer at exactly the right moment.
The result is a print with extraordinary tonal qualities — luminous, split-toned highlights fading into deep, gritty shadows, with colours that range from peach to chocolate to cold grey depending on the paper, the dilution, the temperature, the age of the developer, and a dozen other variables you only partially control.
If you are a physicist, you recognise this immediately. You are working at the edge of an instability. You are riding a nonlinear dynamical process, using your hands and your eyes — not a feedback controller, not a PID loop — to pull the print out at the right moment on an exponential curve. You are doing exactly what an experimentalist does when they tune a qubit to the edge of a phase transition, or when they push a SQUID to just below its critical current. You are operating in the regime where small perturbations have large consequences, and where the only reliable instrument is your own accumulated experience.
Every lith print is different. You cannot reproduce one exactly. You can get close — you can control your variables and be disciplined — but the chemistry has its own opinions. This is not a flaw. This is the point.
Sabattier
The Sabattier effect — often incorrectly called solarisation — is produced by briefly re-exposing a print (or negative) to light partway through development, then continuing to develop. What results is a partial reversal of tones: areas that were becoming dark are arrested, while previously unexposed areas begin to develop. A distinct line — the Mackie line — forms at the boundary between light and dark regions, an edge effect produced by the chemistry of adjacent areas interacting with each other.
The print holds both the positive and the negative simultaneously. It contains the image and its inverse, superposed.
I am wary of cheap quantum metaphors. The popular press has done enough damage with “Schrödinger's cat” as a stand-in for anything that might be two things at once. But the Sabattier effect is not a metaphor for superposition — it is an actual physical system exhibiting the coexistence of two opposing states, separated by a boundary that only exists because of their interaction. The Mackie line is real. It emerges from the local depletion of developer at the boundary between exposed and unexposed regions, a diffusion-driven process that produces structure where there was none.
What I find most compelling about the Sabattier effect is the decision it encodes. You choose when to re-expose. Too early, and you get a near-complete reversal — an eerie, ghostly negative. Too late, and the effect is barely visible. The moment you choose determines the ratio of positive to negative in the final image, and you cannot undo it. There is no going back. You commit, and you live with the consequences.
This is experimental science. Every measurement is an intervention. Every choice of when to read out a qubit, when to apply a pulse, when to terminate a sequence — these are irreversible commitments made under imperfect information. The experimenter, like the printer, is embedded in the system. Your actions change the outcome.
Mordançage
If lith printing is about riding instability and the Sabattier effect is about coexistence and commitment, then mordançage is about destruction as creation.
The process works like this: you make a conventional black-and-white print, fully developed and fixed. Then you immerse it in a mordançage bath — a solution containing potassium dichromate, acetic acid, and copper chloride (or variants thereof). The bleach attacks the darkest areas of the print, the places where the most metallic silver sits in the emulsion. As the silver is dissolved, the gelatin in those areas lifts and blisters away from the paper base. You can peel it back, push it around with a brush or a jet of water, fold it over itself. The shadows literally detach and become sculptural.
Then you redevelop. The remaining silver halide in the emulsion — the parts that weren't originally exposed — now develops to black. What was light becomes dark. What was dark is gone, peeled away or floating. The print is transformed utterly. It bears traces of its original image, but it is something else now: a relief, a ruin, a new object.
You cannot plan a mordançage print in advance. You can have intentions, but the bleach will do what the chemistry dictates, and the gelatin will lift where it wants to lift. You work with what emerges. You respond. And the prints you make through this process are categorically irreproducible. Each one is a unique physical object — not a copy, not a print in the reproductive sense, but a singular artefact created through a partially controlled destruction.
In the cleanroom, some of the most important discoveries I've witnessed have come from processes that went wrong in generative ways. An etch that undercut unexpectedly and revealed a structure no one had designed. A junction oxidation that drifted and produced a device with anomalous properties worth investigating. The ability to recognise when a failure is actually a finding — when destruction has created something — is one of the most important skills an experimentalist can develop. Mordançage trains exactly this perception.
What the darkroom teaches
I want to be precise about the claim I'm making, because it's easy to slide into vague gestures about “creativity” and “science” being “connected.” That kind of talk is pleasant but toothless. I am making a stronger claim.
The practice of experimental science and the practice of analogue photography share the same fundamental structure. Both involve: direct physical engagement with materials that have their own properties and resistances. Both require the development of tacit knowledge — embodied skill that cannot be fully articulated. Both operate in regimes where you have partial control and must respond to what the system gives you. Both demand comfort with irreversibility, with the fact that you cannot undo your interventions. And both produce unique, unrepeatable results — no two experimental runs are identical, just as no two darkroom prints are identical, even from the same negative.
This is not a metaphor. It is a description of what it means to work experimentally.
When I moved away from the bench and into management — when my days became meetings and emails and strategy documents — I did not stop being an experimentalist. But I lost the context in which that identity could express itself. I lost the physical engagement, the tacit learning, the daily negotiation with materials. The darkroom gave it back.
Not as compensation. Not as therapy. As continuation.
The community
One thing I did not fully anticipate when I started showing work and talking about this publicly is how many people in science carry a similar tension. Physicists who paint. Engineers who throw ceramics. Mathematicians who play jazz with a seriousness that rivals their research. These are not weekend diversions. For many of us, they are essential — they are the part of the practice that the institution doesn't accommodate but that the practitioner cannot do without.
The International Year of Quantum Science and Technology — IYQ 2025 — has created space for these conversations in a way that feels new. The fact that NPL programmed a panel on art and creativity at the end of a day about metrology was significant. It said: this matters. It is part of what we do. And the response — the full room at 5pm, the conversations that followed, the metrologist in the mountains of Trento months later still thinking about it — tells me the appetite is real.
I don't think we need to justify art to scientists by proving it makes them “more creative” or “better problem-solvers” in some instrumentalised sense. That framing diminishes both practices. What I want to say instead is simpler: if you are an experimentalist, you already know how to make art. You already have the skills — the patience, the material intuition, the comfort with failure, the eye for when something unexpected is actually something important. You do it every day in the lab. The only question is whether you also do it somewhere else.
For me, that somewhere else is a darkroom in Finland, smelling of acetic acid and fixer, my hands stained with silver, pulling a lith print out of the developer at exactly the moment the shadows start to race. It feels like science. Because it is.
Jorden Senior is a Research Team Leader in Quantum Computing Hardware at VTT Technical Research Centre of Finland. He works with 35mm and medium format film, and prints using traditional silver gelatin, lith, mordançage, and Sabattier techniques.