Solarigraphy is a photographic method that uses very long exposures – often around six months—to record the Sun’s paths with simple pinhole cameras. Paweł Kula shares how it started with the “Solaris” project, which combines observation, DIY making, and global sharing. It reveals slow changes in landscapes and cities, while encouraging experimentation and an open, collaborative approach to photography.
What is solarigraphy?
Solarigraphy is a method based on extremely long, uninterrupted exposure of the sky and elements of the landscape using a self-built pinhole camera with light-sensitive photographic paper. The aim is to capture the paths of the Sun over a six-month period between successive solstices. In this method, a negative image forms spontaneously inside the camera and does not require chemical development. At a later stage, it is digitized, inverted into a positive, and further processed using digital post-production. An equally important aspect is the sharing of the resulting images online.
However, this definition does not fully capture the original spirit of the idea—solarigraphy is more than just a way of making a photograph. Above all, it is an experience of time and space; a way of being attentive and closer to nature; an act of waiting, and also a personal journey inward.
Conversations about solarigraphy often revolve around the circumstances in which an image was made—the search for the right place to install the camera and the gradual familiarity with the chosen view. There is also plenty of room for chance, for drifting, and for accepting whatever unfolds—for disappointment, but also for a sense of play. Solarigraphs, regardless of who made them, can often appear strikingly similar. And yet, each one carries a unique story—an individual experience and journey.
The “Solaris” Project
The foundations of this method were formulated in November 2000 during a meeting between Paweł Kula and Sławomir Decyk (then photography students at the Academy of Fine Arts in Poznań) and the Spanish photographer Diego López Calvín in Szczecin and Police (Poland). We named our joint experiment the “Solaris Project” as an expression of our shared fascination with the Sun, the literature of Stanisław Lem, and themes found in the films of Andrei Tarkovsky.
An important component of the project’s dynamic was the individual inspirations of those involved. Diego López Calvín recalls that at the time, the Sun was a central motif in his artistic work, including his role as a photographer on the set of “Lucía y el sexo” (directed by Julio Medem). His visit to Poland, during the darkest days of a rainy autumn, came as a striking contrast. As he mentioned in our last conversation: “…solarigraphy began at the moment of my first journey from the South to the North.”
Sławomir Decyk, in his student work at the time, frequently explored long exposure times, images built through multiple exposures, and recordings of the Sun’s movement. He was also the one who initiated the meeting between the three of us.
Within the circle of people inspired by the project at that time were other students from the Academy of Fine Arts, including Konrad Smoleński and Wojtek Hoffmann, who were actively experimenting by building cameras and exposing photographic paper using the lumen print technique.
For my part, it is difficult to separate the story of solarigraphy from my personal fascination with astronomy and photography. As a teenager, I already understood the movements of the Moon and the planets, could estimate the time of night and the season from the appearance of the sky, and carried out observations using simple, self-built telescopes. From the mid-1990s, using handmade pinhole cameras, I recorded the Moon’s paths over entire nights and the Sun’s paths over full days, using modified development processes, filters, and low-sensitivity materials.
Dominique Stroobant and Eric Renner
In 1997, I came across the book Pinhole Photography: Rediscovering a Historic Technique by Eric Renner. There, I encountered the photographs of Dominique Stroobant—cityscapes and skies marked by striking lines. These images, made with four different cameras, were partially solarized: the brightest areas inverted into a positive while shadows remained negative. Exposed between December 22, 1981 and June 22, 1982, they revealed the paths of the Sun—images I immediately understood.
Stroobant’s work became the impulse that pushed me to pursue multi-month, and later multi-year, exposures in my own experiments. Around the same time, I was also impressed by the photographs of Hiroshi Yamazaki. I did not yet know that, in nearby Berlin, Michael Wesely had already created his long-exposure series.
Between 1998 and 2000, I carried out numerous tests—one-day, week-long, and two-month exposures. The last of these experiments were made using a simplified method that is now known as solarigraphy.
The first solarigraphs and terminology
The first collective solarigraphic exposure within the “Solaris” Project began at the winter solstice in December 2000 and was intended to conclude six months later. Our aim was not only to record the Sun’s paths, but also to observe how these images change with latitude. What interested us most were places we had never reached—the regions near the equator and the poles.
For this reason, it was important to involve participants from different parts of the world, to share the idea online without restrictions, and to freely exchange results. From the beginning, we understood that without a collective effort, we would not be able to see in reality what we had first imagined.
The technique itself was simplified to the greatest extent possible. Solarigraphy is essentially photographic paper that darkens under light, placed inside a pinhole camera. With basic instructions, anyone could build a camera in minutes and, after exposure, use a scanner and software to obtain a colour positive.
The method was first published online by Diego López Calvín (www.solarigrafia.com). It was intended to remain open and non-commercial, allowing anyone to develop it further. In 2001–2002, solarigraphy was practiced by only a small number of people worldwide. The term appeared initially in Polish and Spanish publications (“solarigrafia” / “solarigrafía”).
In 2003, the idea entered the English-speaking internet through Tarja Trygg, who – after attending our workshop in Poland the year before – created the website solargraphy.com. This played a key role in spreading the method. Also see Tarja Trygg’s article Solargraphy – The art of catching the sun’s path through a pinhole camera. At the same time, Diego López Calvín introduced the term “solarigraphy,” referring to the Sun, the act of writing, and the international, internet-based nature of the project.
All of these names describe the same experiment, and in this text I use the term “solarigraphy.”
Technical components of solarigraphy
Solarigraphy combines two long-known phenomena: optical projection and photochemical reaction.
The first is the camera obscura. Light travels in straight lines, and a small opening in a light-tight container can project an image. When the aperture is very small (typically f/100–f/200), the image has great depth of field but very low light intensity—conditions suited to long exposures.
The second component is black-and-white photographic paper containing light-sensitive silver salts. In solarigraphy, no chemical development is used. The paper reacts directly to daylight—especially blue and UV light—and gradually darkens.
This process is related to lumen printing, where long exposures produce coloured images without a camera. In this sense, solarigraphy can be understood as a form of lumen printing inside a camera obscura.
After months of exposure, the camera contains a ready-made negative. This is still light-sensitive and should be digitized quickly. The final image is created by inverting the negative and adjusting colour and contrast digitally.
A journey into the past
The darkening of silver salts under sunlight was studied at the end of the 18th century. Researchers observed that these materials could shift from pale colours to deep browns under exposure.
William Henry Fox Talbot used similar principles in the 1830s. In 1835, he recorded a window using a simple camera and light-sensitive paper, producing one of the earliest photographic negatives.
Talbot soon moved to chemically developed processes, which dramatically reduced exposure times. In a sense, solarigraphy moves in the opposite direction—returning to long exposures and direct light action.
What we see in solarigraphy
Solarigraphy primarily records the Sun’s apparent motion, caused by Earth’s rotation and its orbit around the Sun. The tilt of Earth’s axis (23.4°) causes the Sun’s path to shift over the year.
The appearance of these paths depends on latitude. Near the equator, the Sun rises steeply; toward the poles, it moves parallel to the horizon during polar day.
Beyond solar paths, solarigraphs reveal phenomena not normally visible: seasonal changes in vegetation, construction and demolition, repeated reflections, and traces of human activity.
Moreover, at mid-latitudes in the Northern Hemisphere, the rising Sun moves across the sky from left to right, reaching its highest point toward the south. In contrast, at mid-latitudes in the Southern Hemisphere, this movement occurs in the opposite direction. This is a detail that often surprises those crossing the equator for the first time and looking up at the sky. It is simply a consequence of the geometry of a spherical planet.
Views beyond human perception
Our perception is shaped by the way our senses operate. In a sense, reality is continuously formed through seeing, touching, sensing smells and temperature changes, and receiving sound waves. Solarigraphs present images that are far removed from everyday visual experience, primarily because of their extremely long exposure times. When a single “glance” lasts a week, a month, or even a year, the photograph becomes a synthesis of many phenomena that would normally remain invisible.
Beyond recording the Sun’s six-month journey across the sky and periods of cloud cover (visible as breaks in the lines), solarigraphs also reveal slower, less obvious changes. These include seasonal transformations in vegetation (such as the appearance and disappearance of leaves), the growth and movement of plants, changes in snow cover, and even ocean tides.
In urban environments, where human activity dominates, additional artifacts emerge. These can include multiplied forms of cars parked in the same place, semi-transparent buildings captured during construction or demolition, repeated streaks of light caused by sunlight reflecting off vehicle windows, and overlapping imagery on billboards.
Although a human figure itself has no chance of appearing in such a photograph, faint hazes and subtle traces can sometimes be seen in areas where people regularly sit, walk, or gather.
Paper response: colour, moisture, solarization
The colours of a solarigraphic negative result from silver salts reacting to light. This process produces a characteristic range of hues—from delicate pinks and violets through blues and greens, sometimes reds, and finally deep browns. The image removed from the camera can be strikingly multicoloured, but these colours do not correspond to those of the photographed scene.
Instead, the palette is shaped primarily by the intensity and duration of light, the type of photographic paper used, and the presence of moisture. With suitable paper, strong exposure, and high humidity, the reaction can proceed more quickly and produce rich, saturated colours.
The Sun’s paths can also vary in colour depending on when they were formed during the exposure. From the image alone, it is not possible to determine whether the exposure ran from December to June or vice versa. However, if the exposure begins during the longest days (June in the Northern Hemisphere, December in the Southern), the longest and most intense lines are formed on unexposed paper, while shorter and fainter ones are recorded later on already exposed material. This can result in distinct colour differences, with earlier paths often appearing brighter and more contrast-rich.
It has long been known—from early research on silver salts as well as from lumen printing—that damp paper reacts to light more quickly and often produces more vivid colours. Similar effects can be observed in shorter exposures made in cameras, particularly when the paper remains wet during exposure. In solarigraphy, where exposures last for months, moisture can condense inside the camera and create areas of uneven colour across the surface.
Water inside the camera can also damage the image. The light-sensitive emulsion, based on animal gelatin, may begin to break down under conditions of high temperature and humidity.
With extremely long exposures and direct sunlight, partial reversal of tones may occur in the emulsion. In the most strongly exposed areas—those that are darkest in the negative—the image may begin to fade, producing effects that resemble a positive. This phenomenon, known as classical solarization, typically appears under conditions of extreme overexposure. In solarigraphy, it is most often seen when the pinhole is too large or when exposures extend beyond six months.
Optical artifacts and camera shifts
A range of additional visual effects can occur inside a solarigraphic camera, resulting from both the nature of the pinhole system and the presence of the Sun within the frame. Reflections of the Sun’s disc are among the most common. One contributing factor is the use of glossy photographic paper—matte or semi-matte papers are generally preferred to reduce this effect.
In cylindrical cameras made from beverage cans, it is also common to see blurred or shifted repetitions of parts of the Sun’s paths. This is caused by the curvature of the paper and the extremely wide angle of view, which allows light from extreme directions to reflect within the camera. Such effects are less common in other camera shapes and when matte paper is used. A frequent mistake is failing to darken the interior of a reflective camera, which reduces contrast and overall image quality.
If the camera contains more than one pinhole, multiple images will appear. Similar duplication can result from sudden shifts in the camera’s position during exposure. In many cases, it is possible to estimate when such a movement occurred by analysing the negative. If the image is not duplicated but appears blurred, this usually indicates continuous movement of the camera or its support. Wind can cause significant motion, particularly when cameras are attached to trees, fences, or lightweight structures. More subtle factors—such as temperature changes, plant growth, or even minor structural shifts—can also introduce distortion.
Building a solarigraphic camera
At its core, building a solarigraphic camera is no different from constructing a standard pinhole camera. The process has always been rooted in a DIY approach, often using readily available or recycled materials. You can find instructions on how to build a camera here.
The camera body is typically made from a small aluminium can. After removing the top section, the interior is painted matte black to reduce reflections. This cylindrical form provides a very wide field of view, though it also introduces characteristic distortions, particularly toward the edges of the image.
Installing the camera
Orient the camera according to the cardinal directions, depending on whether you want to capture sunrises, sunsets, or the Sun at its highest point above the horizon. Attach the camera to any suitable surface using sanitary silicone. The camera is lightweight, and the silicone will hold it firmly in place after a short while. Once everything is ready, remove the cover from the pinhole—this marks the beginning of the exposure. Some people use mounting adhesives or cable ties instead of silicone, which can work well for heavier cameras.
Notes:
When mounting the camera vertically, place the opening at the bottom—this reduces the chance of rain entering the camera and damaging the image. You can install the camera in a location that is not easily accessible to passersby and camouflage it—for example, by painting the exterior black. Cameras placed in public spaces are often opened by curious people, and sometimes even removed by police or bomb disposal units as suspected explosive devices. If you want to avoid such situations, place the camera discreetly, camouflage it, or clearly label it—ideally, do all of these.
It is impossible to anticipate every situation—be prepared for the fact that some cameras may disappear without a trace or be damaged by people, animals, or weather conditions. These situations are also part of the practice of solarigraphy.
Exposure time
In the classical approach, a solarigraphic exposure begins and ends at the solstices, meaning the image is exposed for half a year. Such a photograph shows the Sun’s paths from its highest to its lowest position—assuming every day during that period was sunny. Of course, this is rarely the case, and variations in sunlight will clearly distinguish images made in Scotland from those taken in Spain.
The solstices are key turning points in the Sun’s apparent path across the sky:
On June 22, the summer solstice occurs in the Northern Hemisphere. The Sun reaches the zenith above the Tropic of Cancer (23.4°N), while at the North Pole it is the middle of the polar day—the Sun circles the sky 24 hours a day at about 23.4° above the horizon. In the Southern Hemisphere, this marks the winter solstice, and at the South Pole it is the middle of the six-month polar night.
On December 22, the winter solstice occurs in the Northern Hemisphere. The Sun reaches the zenith above the Tropic of Capricorn (23.4°S). Astronomical winter begins in the north, while summer begins in the south. At the North Pole, this is the middle of the polar night, while at the South Pole the Sun moves parallel to the horizon at an altitude of about 23.4°.
The equinoxes—March 21 and September 23—mark the midpoint between the solstices. On these days, the Sun rises exactly in the east and sets exactly in the west, and at the equator it reaches the zenith at noon.
Notes:
If you shorten the exposure, you capture only a fragment of the Sun’s journey; if you extend it, the solar paths begin to overlap. Using a lens-based camera with a fast lens, a solarigraphic negative can form in just a few minutes. At the other extreme, the longest solarigraph I am aware of was exposed in a pinhole camera for over nine years—and this is unlikely to be the technological limit.
I’ve exposed a solarigraph—what next?
Once the exposure is complete and the camera has been retrieved, it can be opened under dim light—for example, from a bedside lamp. Daylight and white LED light should be avoided. The negative will remain stable if stored in a dark, dry place, but as it is unfixed, it remains light-sensitive.
The next step is digitisation at the highest possible quality. The image can be scanned using a flatbed scanner or photographed with a digital camera. This digital negative becomes the basis for the final image.
Using image-editing software, follow these steps: invert the negative into a positive → flip the image left to right → adjust contrast and colour balance. The solarigraph is then complete.
Notes:
Scanner light can significantly alter the original negative, so it should ideally be scanned only once, at the highest quality (wide tonal range and maximum resolution). This process is slow and may irreversibly affect the original. To preserve it unchanged, photograph it using a digital camera with studio flash or low continuous light (minimal ISO, RAW format).
If the negative is very dark, it can be fixed using a standard black-and-white photographic fixer (sodium thiosulfate). This will lighten the image and remove many of the original colour nuances. A fixed negative is no longer light-sensitive and can be displayed without protection.
The colours in solarigraphy are not literal—they arise from the behaviour of silver salts under prolonged exposure. An unmodified positive typically has a green-blue cast and relatively low contrast. During post-processing, adjustments are often made to expand tonal range, refine contrast, calibrate colour, and remove defects. The final result ultimately reflects an individual approach.
Summary
After 25 years, solarigraphy has far exceeded the expectations of its creators. It is now practiced worldwide and recognised as an independent photographic technique.
Its strength lies in its simplicity, accessibility, and combination of historical and digital methods. It continues to attract artists, educators, and researchers.
Many projects have expanded far beyond the original idea. It has developed in ways that could not have been predicted—and in the best possible direction.
SOLARIGRAPHY — WHAT NEXT? Links to selected projects inspired by solarigraphy:
- The first and oldest website dedicated to solarigraphy (2001): www.solarigrafia.com — Diego López Calvín
- The first online platform collecting and showcasing photographs by authors from around the world (2003): www.solargraphy.com — Tarja Trygg
- A year-long solarigraphic animation of the Sun (2001-2002): https://vimeo.com/847228819 — Paweł Kula
- A 30-frame animation of six-month solarigraphs (2024): https://vimeo.com/1045771182 – Paweł Kula
- Solarigraphic analemma project (since 2013): https://analemma.pl/english–version — Maciej Zapiór, Łukasz Fajfrowski
- Circumnavigation in Time Project (2025): http://circumnavigationintime.avcr.cz/en/ — Maciej Zapiór, Artem Koval
Solarigraphy in the APOD gallery (NASA) — from earliest:
- 2009: https://apod.nasa.gov/apod/ap090115.html – Justin Quinnell
- 2012: https://apod.nasa.gov/apod/ap120121.html – Regina Valkenborgh
- 2014: https://apod.nasa.gov/apod/ap140320.html – Maciej Zapiór, Łukasz Fajfrowski
- 2016: https://apod.nasa.gov/apod/ap160326.html – Olivér Nagy
- 2019: https://apod.nasa.gov/apod/ap191221.html – Sam Cornwell
- 2022: https://apod.nasa.gov/apod/ap220702.html – Dawid Rycąbel
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