1. author — Tania Woloshyn
  2. published in — Light Break – Photography / Light Therapy
  3. year — 2015

Towards the Light: History of Photography and Phototherapy’ Essay for Nicolai Howalt’s exhibition catalogue, Light Break

Artifact: A visible sign of the process by which an image is made. Artifacts can be a result of the camera or lens technology, the exposure, the emulsion or the development of the film. What is an undesirable artifact for some is a useful piece of information for others. – Kelley Wilder, Photography and Science, 2009

Light Break presents an innovative body of work by contemporary Danish photographer, Nicolai Howalt (1970- ), exploring convergences between aesthetic and therapeutic interests in light – where art meets medicine on the photosensitive surface. A continuation of Howalt’s wider interest in visualising the invisible, the series’ photographs and photograms bring to light the
muchforgotten and largely hidden remnants of the medical practices of Nobel laureate, Dr Niels Ryberg Finsen
(1860-1904), and the Finsen Institute in Copenhagen.
Finsen won a Nobel Prize in 1903 for inventing artificial light therapy, known as ‘phototherapy,’ to treat patients suffering from skin diseases such as lupus vulgaris (tuberculosis of the skin) This was a particularly disfiguring disease, most often attacking the face, and with no known cure it forced sufferers to hide away from the public eye. Treatments available during the nineteenth century were painful and often ineffective, involving cutting or chemically burning affected parts of the skin. Exploiting the therapeutic potential of the region of the electromagnetic spectrum that could kill germs – the blue, violet and ultraviolet rays that together made up what was called ‘actinic’ or ‘chemical’ light – Finsen harnessed first natural sunlight and then artificial light, generated by electric arc lamps, during the 1890s. Focussing this powerful light through lenses, and channelling it down telescopic arms, he aimed these light rays directly onto the infected skin of his patients, with remarkable results that astounded not only Denmark’s medical community but the global public.

Finsen’s therapeutic use of light was known all over the world, his successes reported in medical journals and popular newspapers alike. Phototherapy was the artificial complement to natural sunlight therapy, known as ‘heliotherapy’ – a kind of medical sunbathing, which Finsen also advocated. In 1896, he founded the Medical Light Institute in Copenhagen, which was later renamed the Finsen Institute and was funded by private donations and the state. Though Finsen died in 1904, only one year after receiving the Nobel Prize, the Institute carried on thriving during the twentieth century, later merging with Copenhagen University Hospital and now serving as a cancer research laboratory, the Finsen Laboratory.

Scattered across various archives in Copenhagen, including a major holding within the Medical Museion, Finsen’s extensive collection of documents, photographs and equipment is rarely seen and little discussed by medical historians, despite his fame during the turn of the century and his seminal role in phototherapy (a medical treatment still used today to treat various skin infections, such as psoriasis, and Seasonal Affective Disorder [SAD]).
Howalt’s Light Break series invites us to reflect on the long-standing relationship between phototherapy and photography, and, in particular, Finsen’s own investment in photography. This was a medium that Finsen relied upon heavily not only to document patients’ improvement and communicate the therapy’s successes in his publications, but above all to understand the transformative powers of actinic light: by understanding how photography worked, Finsen gained important knowledge about the latest developments in photochemistry and light physics. Finsen’s inventions were grounded in the very processes of visualising and image making: photography, optics, and electric lighting.

Howalt has gained intimate access to the Finsen archive in the Medical Museion, including the use of original phototherapy equipment such as lenses. The original Finsen equipment serves both as subject matter, but also as tools for aesthetic and photochemical experimentation extending beyond their original contexts. Howalt registers and aestheticises the excessive, often volatile actinic light Finsen found so desirable for destroying lesions, burning skin and blinding eyes, thereby pushing analogue photography to its limits as a medium of ‘light-writing’ (photo-graphy). By pointing his large format camera back onto the archive and through its objects, Howalt’s work simultaneously documents and interlaces the convergence between photography and phototherapy.

Phototherapy and photography:
The sun’s ability to blacken silver salts had been known since 1725, by the anatomy professor Johann Heinrich Schulze and confirmed by experiments during the 1770s by the Swedish apothecary Carl Wilhelm Scheele. The experiments by the German chemist Johann Wilhelm Ritter clarified that it was the invisible, ultraviolet rays of the spectrum that had the most ‘chemical’ effect, using paper coated with silver chloride in a dark room, following the earlier research of the botanist Jean Senebier in 1782.
Ritter is credited with discovering ultraviolet rays in 1801, one year after Sir William Herschel discovered the infrared (ultrared) rays. Like Wilhelm Röntgen (X rays) and Henri Becquerel (gamma rays) almost one hundred years later, these invisible ultraviolet rays were first detected and discovered by photographic action.
Photography’s ability to detect invisible phenomena, and specifically wavelengths on the electromagnetic spectrum invisible to the human eye, proved an invaluable resource for scientists.

When it comes to ‘seeing’ ultraviolet light, we are always in the dark.
‘The two ends of the spectrum gradually fade away into darkness…’ stated Shelford Bidwell in his popular book Curiosities of Light and Sight (1899), and ‘…we cannot see them; they fall upon our eyes without exciting the faintest sensation of light.’ Yet he persisted in stating the similarities between the workings of the human eye and that of the camera,
a long-held connection in photography’s history. Photography offered to enlighten the eye to these invisible rays, detecting and visualising that which it cannot naturally see, just as telescopes, camera obscuras, magic lanterns and microscopes provided an ‘extra-ocular way of observing the world.’ As a scientific tool that registered the actinic rays, photography became an important medium for Finsen and helped him understand why light – especially ultraviolet light – could be used as a source of healing.

Finsen’s experiments with light began during the early 1890s through an observation of its negative influence on variola, also known as smallpox.
This was a particularly common infectious disease with symptoms of fever, rash and blistering of the skin. If sufferers survived, they were frequently left with marks, pits and scars on their faces and bodies. Finsen, following several historic but vague examples, discovered that the blue, violet and ultraviolet rays (actinic light) worsened the disease, and consequently developed ‘red light therapy.’ He placed smallpox patients in a room where all the windows were covered with thick, red cloth or a dense red glass, to filter out all but the red rays of the spectrum.
If the patient was put in this red-light treatment room during the first stages of smallpox, known as the stage of vesiculation (blistering of the skin), the disease did not develop into the stage of suppuration (in which pus would discharge from the small blisters).
By doing so the patient could heal with little or no scarring. It therefore was not a cure, per se, but a method of managing the illness and minimising risk, including complications and fatalities, at a time when smallpox vaccination was not yet fully widespread throughout Europe.

Describing his red light therapy, Finsen stated in an 1895 article in the British Medical Journal that, The exclusion of the chemical rays must be absolute; even a brief exposure to daylight may produce suppuration and its sequelae. In other words, the skin during small-pox is as susceptible to daylight as a photographic plate, and must be kept from the chemical rays in the same way and almost as carefully.

As Finsen made clear, red light therapy operated according to knowledge gained from photographic practices: the patient’s skin was as photosensitive to actinic light as a photographic plate; his treatment room, as a result, emulated a darkroom. He made sure the conditions were right before allowing his patients to enter by hanging a photographic plate in the centre of the room.
Any blackening of the emulsion on the plate indicated actinic light was somewhere filtering into the room and therefore it was not safe for patients to enter. From his early experiments then he understood that actinic light – the blue, violet and ultraviolet rays – could be damaging to sensitive skin and he consequently referred to them as the ‘injurious’ rays. Red light therapy for smallpox patients therefore avoided actinic light, but Finsen also turned his attention towards these injurious rays to investigate their potential healing, transformative powers.

In his writings Finsen explained that he became aware of the destructive powers of actinic light by conducting experiments with sunlight in 1893, using himself as a test subject. In one experiment, he held his forearm close to a carbon arc lamp for twenty minutes. He glued several different pieces of coloured glass and a disc of quartz glass to his arm, as well as painting his initials in India ink.

American physicist and lighting designer for General Electric, Matthew Luckiesh, with August John Pacini, in their 1926 book Light and Health. Luckiesh and Pacini offered details of the experiment as follows:

Finsen, a quarter of a century ago, studied the influence of light on the skin. He made few and simple experiments, but they were devised, performed and interpreted with an unerring instinct rightly termed genius. In one of his experiments he exposed his white and unpigmented forearm to the light from a 40,000 candle-power arc-lamp at a distance of 50 centimeters for ten minutes. At this distance the heat became disagreeable, so he exposed the arm ten minutes longer at 75 centimeters. He had glued on his arm a disc of quartz and a series of glass plates – red, yellow, blue and clear. He also painted the initials N F and other figures with India ink.

In this experiment Finsen tested the transparencies of these different materials to the actinic rays, specifically seeking to understand which ones would allow ultraviolet light to pass through them. By doing so, he used his own arm to register light.
The sunburn (or ‘solar erythema’) that appeared three hours later, photographed the following day, was a reaction he had counted on as a gauge. In this experiment his arm became a testing ground, akin to a sensitive photographic plate, to reveal the transmitting properties of the different kinds of glass. Finsen noted that sunburn developed on the uncovered portions of his forearm and through the quartz glass, save for the bits of glue, but not on the skin covered by the coloured or clear ordinary glass plates and India ink. He concluded that quartz glass allows the actinic rays of light to pass through it, whereas ordinary glass does not. This information would prove particularly valuable to Finsen in his invention of the ‘Finsen Lamp.’

Underpinning light therapy as a medical treatment was the fundamental notion that the skin is a natural photometer for detecting and measuring actinic light.
Physicians found evidence for the efficacy of the actinic rays, whether natural or artificially produced, in photography itself as a light-sensitive medium. The ‘chemical’ (photochemical) power of actinic light to blacken or sensitise photographic paper was asserted over and over again by physicians interested in the therapeutic potential of light. The logic went that if these rays could act on photographic surfaces, they could act in a like manner on the patient’s skin; that is, photochemically.
Such photochemical action was registered on the skin as sunburn and suntan.
Skin and photograph were understood to operate in the same manner in response to actinic light, especially ultraviolet light, and long after Finsen as this 1928 quote indicates:

The normal white skin is sensitive to ultra-violet rays from 2,970 to 2,500 A.U., and this sensitiveness is comparable to the effect of visible rays on the photographic light sensitive plate. There is, in all probability, some photo-biochemical effect produced, which controls these reactions, which are typically characteristic of light erythema [sunburn].

The complicated convergence of aesthetic and therapeutic light occurs in other photographs of light therapy, not only those presenting sunburnt skin. In the 1901 English translation of his book, Phototherapy, Finsen included several plates of his patients and described them as evidence of light therapy’s good effects on patients.
In his many before-and-after photographs of lupus vulgaris patients the therapeutic process is visually absent, merely implied in the spaces between the two photographs – but we are presented with images produced by and about actinic light. Like other medical and scientific researchers of his time, Finsen used photography both to explain photochemical processes, for therapeutic application, and to act as a recording device for his results with that same actinic light.

Finsen clearly considered these before-and-after photographs important documents, even ‘portraits’ of his patients. Where is the boundary between ‘portrait’ and ‘medical case study’ in these photographs? We encounter patients who have taken great care to present their best self, with their hair combed and put up, and brooches and fine collars chosen for clothing. Since we know that these people, suffering from lupus vulgaris, normally hid away from public view, it is significant that the experience of sitting for these photographs in the Finsen Institute was a unique moment for self-representation. From the obscurity of seclusion they are ‘brought to light’: physically, in venturing outside to the Institute to go ‘to the light (mod lyset),’ as patients referred to their appointments; therapeutically, by being exposed to the actinic light for treatment; and aesthetically, to the camera’s eye, to Finsen’s eyes and to ours as viewers.
Howalt has additionally made photographs of these before-and-after photographs, presenting a further layer of light registers.

Phototherapy, Electric Lighting
and Optics:
Finsen’s early experiments were followed by his novel modification of the carbon arc lamp, which became famously known as the ‘Finsen light’ or ‘Finsen lamp’.
The carbon arc lamp was a form of electric lighting that had been invented at the beginning of the nineteenth century by the British chemist and proto-photographer, Sir Humphry Davy, contemporaneous with his early photographic experiments and Ritter’s discovery of ultraviolet light.
By the mid-nineteenth century the carbon arc was used in welding and to light railway stations, public streets, theatres, and even the low-lit interiors of photographic studios. The carbon arc lamp emits a brilliant white light in an arch formation when an electrical current is passed between its two rods of carbon, making it ideal for lighting large public spaces or, when focused with mirrors or plano-convex lenses, for spotlights and searchlights (illuminating distances up to six kilometres).
Significantly, Finsen’s earliest trials with carbon arc lamps occurred in 1895 not in a hospital but at Copenhagen’s first power plant, the Copenhagen Electric Light Works (Københavns Elektriske Lysstation), where one of the engineers, Niels Mogensen, suffered from lupus vulgaris and served as Finsen’s first test case.

In his modifications to the lamp Finsen channelled the emitting light of the arc into brass telescopic arms that were fitted with ultraviolet-transmitting quartz lenses – a lesson learned through self-experimentation. In addition to using pyrogallic acid (a staple in photographic darkrooms), alongside light therapy to treat lupus lesions, Finsen experimented with various lenses, coloured glass and additional filters, as well as coloured stain solutions applied to the lenses in order to absorb heat from the red and infrared rays.

Finsen would first systematically use glass lenses to focus natural sunlight outdoors on his patients. This use of lenses to focus and concentrate sunlight was not without precedent, in optics or medicine. Various references throughout the centuries exist by physicians who used concentrated sunlight to treat skin lesions using ‘burning glasses’ and ‘burning mirrors.’ Focussing natural light through lenses and mirrors to produce intense heat in fact had ancient origins in Archimedes, who famously set fire to enemy ships with burning mirrors during the third century BC.
During Finsen’s time physicians were still attempting to cauterise skin lesions using lenses that concentrated natural and artificial light. Some even designed their lenses using photography equipment, such as camera filters. Original to Finsen was filtering out the heat from the infrared and red rays with blue coatings and water, concentrating the most chemically-active visible rays (blue and violet) and, when using quartz lenses, the invisible ultraviolet rays, in order to destroy the bacteria of tuberculosis.

The telescopic arms of the Finsen lamp were pressed against the skin lesions of lupus vulgaris patients by the hands of skilled nurses. An additional
water-cooled lens was strapped directly to the patient’s face, compressing the skin and draining blood from the area so as to facilitate penetration of the actinic light. By this method the light would directly target each lesion, requiring as much as one hour of this localised (‘local’) treatment. It was precisely because these rays were ‘injurious’ or damaging to skin infected by the bacteria of lupus vulgaris that they proved to be therapeutically useful to the physician.

Aside from this local treatment with the Finsen lamp, the Institute also used carbon arc lamps that were not shielded or channelled through lenses and telescopic arms. In these instances the open flame of the carbon arc light was used for ‘general’ treatment, in which the patient’s whole body was exposed to artificial light for a stimulating light ‘bath’. In photographs of this full-body treatment the powerful, unshielded actinic light splays out in all directions and marks the photographic surface as glaring white orbs and stars, effects typical of lens flare. We also find photographic representations of the actinic light escaping the shields and arms of Finsen lamps in local treatment, the blinding light appearing to consume patients due to extreme overexposure. These bright white orbs, stars and streaks marring the photograph are called artifacts in photography terminology, the ‘accidents’ or ‘injuries’ of overexposure that ruin the photograph. As marks of excessive or disruptive light visibly present on the photograph, these artifacts betray the materiality of the photograph as an object. No longer the transparent stand-in for the thing it represents, the ‘injured’ photograph announces itself as a material sign, disrupting photography’s status as an index of reality.

Howalt’s Light Break series:
Howalt’s engagement with photographing and analysing light that is heavily mediated – by equipment and inventive set-up – emerges from the Light Break series as the product of deliberation and focus. His photographs and photograms, enabled by Finsen’s equipment, visualise the ‘injurious’ rays and present them as the main photographic subject. These are as much ‘portraits’ as Finsen’s before-and-after photographs of his patients, but here Howalt makes portraits of actinic light, of its fickle, powerful and destructive character. He too produces images where the light splays out beyond the rims of the focussing lenses and arms, of its escape from their apparent control.

As pointed out in one audience leaflet on the Light Break series, Howalt allows the light to pass through Finsen’s lenses, but with a very different aim.
Beautiful aesthetic ‘accidents’ (artifacts) result, producing abstract swirls and scatterings, bleeding colour reversals and black suns emanating on the photosensitive surface like dilating retinas. His photographs and photograms visualise and aestheticise the rays to which our own retinas remain blind.
These artifacts of light, made visible through his photography with Finsen’s equipment, signal Howalt’s open, ongoing engagement with experimentation, of his ‘accumulative method,’ one far more playful than – though perhaps just as rigorous as – Finsen’s own experimentation with actinic light and ‘light-writing’. The surprising results, revealed to Howalt only in the process of development in the hidden recesses of the darkroom, border on the alchemical.

Strapping the lenses to his camera, sandwiching colour, UV and IR filters between them, and channelling sunlight down the lamp’s arms, Howalt reverses Finsen’s processes or, perhaps more appropriately, his 8×10 large format camera absorbs the isolated, broken, filtered light in lieu of the patient’s body. As viewers we are pressed against the lenses and placed at the cusp of the lamp’s telescopic arms, gazing in to them and to the sunlight beyond.
Our perspective is that of the patient’s photosensitive skin, the negative or photogram a kind of skin taking the light’s blinding imprint; the artifacts we see are sunburns and suntans on the photographic surfaces.
There are resonances with Howalt’s previous work, of the before-and-after photographs of boxers – not least in the similar medical formatting and uncanny display tactics of Finsen – as well as his car crash series (Car Crash Studies, 2009). As Howalt points out, these three series all deal with the compulsion to look at something one shouldn’t, and they aestheticise the difficult-to-picture: gruesome before-and-after photographs, car crashes, and direct sunlight.
The Light Break series in particular invite us to meditate on the multiple meanings of ‘glare.’
In her 2008 book The Burning Mirror, photography historian and theorist Melissa Miles explains that, the word ‘glare’ has a double meaning which invests that term with a transgressive and slippery quality. As a verb, to glare means to look intently or to fix with a stare whereas the noun describes a dazzling or oppressive light. At once an agent of fixity and dispersion, glare is a deeply ambivalent concept (in photography).

Miles discusses the work of several contemporary photographers who deliberately play with and aestheticise excessive actinic light, by aiming their cameras directly at the sun (e.g. Danielle Thompson, Marks of Light series, 2003), shining light with mirrors into the camera (Tokihiro Sato, Photo-respirations series, 1988-1990), or lighting their exhibitions with carbon arc lamps (Doug and Mike Starn, Gravity of Light, 2004 installation).
Californian contemporary photographer, Chris McCaw, has similarly been engaged with ‘light-writing’ since 2003 with his Sunburn series, recalling the work of Roger Ackling – a British artist producing artworks by sunlight, focused through magnifying glasses, for almost four decades (e.g. Five hour cloud drawing, 1980, sunlight on card, Arts Council Collection, Southbank Centre, London). Howalt importantly is part of this group of contemporary light-writers, but Light Break presents photographic studies of actinic light intrinsically tied to the issue of health, and specifically to Denmark’s important medical past. As light registers Howalt’s photographs and photograms act as the testing grounds onto which aesthetic and therapeutic light converges and collides. They visualise the powerful, blinding actinic light that Finsen found ‘injurious’ and destructive, but also so desirable for healing.

Finsen’s modified use of carbon arc lamps – originally built and intended for electric lighting – indicate not only that, in its infancy, phototherapy developed out of great and creative experimentation, but also that it was indebted to knowledge of artificial light’s abilities first and foremost to visualise and only second to heal.
The invention of light therapy during the late nineteenth century was closely tied to photography; it could not have existed without the invention of photography, and Finsen’s invention of artificial light therapy (phototherapy) would also not have been possible without the invention of electric lighting. Both electric lighting and photography operated as visualising media: to see, to picture, to capture, and to know. Aiding and enabling the development of light therapy, these visualising media were appropriated by physicians to exploit the therapeutic potential of light.
Howalt re-appropriates photography’s seminal role in light therapy, above all through the work of Finsen.
Finsen is Howalt’s platform, the archive and its historical context a foundation for contemporary experimentation, inspiration and creative analysis.
His Light Break series has prompted new thinking on the history of light therapy and Finsen’s work. Howalt’s photographic practice is an act of exposure: his images bring to light the rarely-seen archival imagery and objects in the Museion’s archive, the long-forgotten lamp technology and hidden patients, here made into ennobling portraits; with his camera and antique phototherapy equipment, Howalt goes to the light (mod lyset) like Finsen’s original patients. Through his photographs and photograms Howalt brings us with him, rendering Finsen’s therapeutic light visible, beautiful, shattered and laid out on the photosensitive surface.