A R T I S T S ’ N O T E
SEEC
Photography at the Speed of Light
E N A R D E D I O S R O D R Í G U E Z , B R A N N O N B . K L O P F E R ,
P H I L I P P H A S L I N G E R A N D T H O M A S J U F F M A N N
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SEEC photography is a project at the intersection of art and science. Es
uses modern technology to record the motion of light, to see c, das ist,
the universal physical constant for the speed of light and the inspiration
for the project name SEEC. In order to familiarize the general public
with this physical phenomenon, SEEC records light moving across
familiar objects, with visual scenes paying homage to iconic images
from the history of photography. Exposure times shorter than 0.3
nanoseconds allow the authors to capture light (Greek: phos) im
process of writing (Greek: graphein) an image.
Light travels at a fast but fi nite speed of 299,792,458 meters
per second. It takes only 3 billionths of a second (3 nanosec-
onds) for light to travel the distance of about 1 meter. Das
speed makes it impossible for us to see the movement of
light; our visual perception is too slow. A successful initial
experimental measurement of the speed of light was done
almost 400 years ago, when Ole Rømer observed Jupiter’s
lunar system [1]. Ever since, the movement of light has re-
mained a topic of intense scientifi c investigation. Heute, light
can be controlled on attosecond timescales (a billionth of a
billionth of a second) [2] and is at the heart of modern com-
munication technology.
Previous cases exist in which a photograph captured the
movement of light. In 1979, at Bell Laboratories, the develop-
ment of an ultrafast shutter based on the optical Kerr eff ect
succeeded in imaging a light pulse in a scattering fl uid [3].
Most recently, MIT Media Lab researchers released several
Enar de Dios Rodríguez (artist, photographer), Studio Enar de Dios Rodríguez,
Hernalser Hauptstraße 56, 1170 Vienna, Österreich.
Email: info@enardediosrodriguez.com.
Brannon B. Klopfer (physicist), Physics Department, Universität in Stanford,
382 Via Pueblo Mall, Stanford, CA 94305, USA. Email: bklopfer@stanford.edu.
Philipp Haslinger (physicist), Vienna Center for Quantum Science and Technology,
Atominstitut, TU Wien, Stadionallee 2, 1020 Vienna, Österreich.
Email: philipp.haslinger@tuwien.ac.at. ORCID: 0000-0002-2911-4787.
Thomas Juffmann (physicist), Faculty of Physics, University of Vienna,
Boltzmanngasse 5, A-1090 Vienna, Österreich; Department of Structural and
Computational Biology, Max Perutz Laboratories, University of Vienna, Campus Vienna
Biocenter 5, A-1030 Vienna, Österreich. Email: thomas.juffmann@univie.ac.at.
ORCID: 0000-0002-7098-5736.
All authors contributed equally to this text.
See https://direct.mit.edu/leon/issue/54/5 for supplemental fi les associated
with this issue.
videos that visualized the propagation of light over small
objects by using “femtophotography” (femtosecond pulsed
laser illumination, picosecond-accurate detectors and math-
ematical reconstruction techniques) [4].
Th e SEEC photography project creates movies [5] made
from sequential photographs that reveal the movement of
light (and the movement of the shadow that light casts),
slowed down by a factor of about one billion, across a wide
variety of everyday objects and scenes. Th ese images of famil-
iar objects are shown as a temporal sequence of light being
scattered and refl ected off of the objects. It thus places fem-
tophotography within the tradition of photography.
Our setup is illustrated in Fig. 1. Th e scene is illuminated
using pulsed lasers, either a titanium sapphire laser (Ven-
teon, wavelength 780 nm, pulse duration ~10 femtoseconds,
repetition rate 80 MHz) or a pulsed and compact laser di-
ode for a mobile version of the apparatus (TEEM photonics,
wavelength 532 nm, pulse duration ~1 nanosecond, repetition
rate 5 kHz).
We use a short-focal-length lens to diverge the laser beam,
eff ectively creating an expanding half-sphere of light, whose
thickness is determined by the product of the laser pulse du-
Feige. 1. SEEC Photography setup. (© SEEC Photography) Laser pulses are
focused by a lens to spread out the light over the object. The gated camera is
triggered to capture the light scattered back from the object at a certain delay
in relation to the laser trigger.
506 LEONARDO, Bd. 54, NEIN. 5, S. 506–509, 2021
https://doi.org/10.1162/leon_a_01940 ©2021 ISAST
Published under a Creative Commons Attribution 4.0 International (CC BY 4.0) Lizenz.
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Feige. 2. Still life (plant), video stills, 2016. (© SEEC Photography)
ration and the speed of light. For the Venteon laser, it is only
3 microns thick; for the TEEM laser the sheet of light is 30 cm
dick. This light then illuminates the object, typically placed
in front of a screen. Light scattered off the object (oder der
screen) is collected by a lens and detected using a gated and
intensified charge-coupled device (CCD) camera (LaVision
PicoStar). The camera is able to detect single photons—the
quanta of light—and allows for exposure times shorter than
0.3 nanoseconds, a time span in which light moves by less
als 10 centimeters. For synchronization of the laser and the
camera, a pick-off of each individual laser pulse is detected
using a fast photodiode, whose signal is amplified, delayed
by the desired interval and connected to and triggering the
camera. Typical averaged power levels were kept below 1 mW
for laser safety reasons.
It is the total distance between the laser light source, Die
object and the camera that determines the time at which
the scattered light reaches the camera. In most of our videos,
the light source and detector are next to each other, und das
object is placed in front of them (as sketched in Fig. 1). Der
parts of the object or scene that are closer to the camera are
illuminated and photographed first. Light scattered from a
more distant part of the object will reach the camera later.
Endlich, the light that did not hit the object reaches the screen
behind it. Light scattered from the screen reveals the shadow
of the object. Because the laser pulse diverges strongly due to
the short-focal-length lens, the pulse first reaches the center of
the screen (Feige. 1) and then seems to grow outward with time.
Figur 2 shows four images of a plant taken at different
delay times between the laser trigger and the gated detection.
One can see how different parts of the plant are illuminated
at different times and also how the shadow grows outward.
Note that the plant and its shadow are not imaged at the same
Zeit. One frame shows the plant without its shadow, and one
frame shows the shadow without the plant. This challenges
our normal understanding that object and shadow are in-
trinsically connected. The contrary is the case: Only the light
that has not interacted with the object will reach the screen
to form a shadow. The reason why the plant appears twice in
the shadow (Feige. 2, Rechts) is that the light first has to travel
from the light source past the plant to the screen and then
back from the screen to the camera. If the laser light pathway
is not precisely in line with the camera detector, the plant
blocks the light bouncing back off the screen to the camera,
creating what looks like a second shadow.
The frames depicted in Fig. 2 are part of a series of movies
depicting classic still life scenarios such as plants or fruit.
For typical laser intensities, and a beam widened to
2 × 2 meters, the illumination intensity is ~1000 photons/
cm²/pulse when using the titanium sapphire laser (~10^7
photons/cm²/pulse for the laser diode). The total collection
efficiency is on the order of ~10^-5, given a typical lens di-
ameter (~3 cm), object distance (~3 m) and detection effi-
ciency (~0.1), which necessitates integration over multiple
laser pulses for a given delay between the laser trigger and
the gated detection. In der Praxis, for each frame of a movie, i.e.
for each delay time, the signal from multiple images is inte-
grated on a CCD chip. For the next frame, the delay is slightly
changed, and again an image is integrated over multiple laser
pulses. The resulting movies depict the movement of light
across different objects and scenes. They are composed of
frames that differ in delay by a few tens of picoseconds, als
indicated at the bottom of each frame. The process described
requires integration times of seconds to minutes. These long
exposure times are reminiscent of the exposure times that
had to be used by the pioneers of early photography to over-
come the low light sensitivity of the technology at the time.
In the Victorian era, several breakthroughs in the technol-
ogy of chronophotography were made that allowed scientific
studies of motion that revolutionized human perception of
Bewegung [6–8]. Our project pays homage to some of the
most iconic images from this photographic period. Unser
recording of the motion of light across a horse head mask
(Feige. 3, top) is an homage to the renowned photographs of
a galloping horse by Eadweard Muybridge, WHO, at the end
of the nineteenth century, developed fast shutters and film
emulsions in order to study animal locomotion. As in Fig. 2,
we see that different parts of the object are illuminated at dif-
ferent times. Note that while Muybridge used light in order
to study the motion of a horse, we use a horse to study the
motion of light. While Muybridge developed photography
with millisecond exposure times, we now use nanosecond
and picosecond exposure times at the forefront of today’s
fast photography.
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de Dios Rodríguez et al., SEEC 507
Feige. 3. After Muybridge (top) and After Marey (center, bottom), video stills, 2017. (© SEEC Photography)
Feige. 4. Portrait (Enar), video stills, 2017. (© SEEC Photography)
508 de Dios Rodríguez et al., SEEC
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In another example that refers to the historic photographic
study of birds’ flight by Étienne-Jules Marey, we recorded
movies of a taxidermied stuffed albatross from different
viewpoints at the Museum of Vertebrate Zoology in Berke-
ley (Feige. 3, center, bottom). Once more, the reference here is
both thematic (capturing motion) and aesthetic (using the
subject of a bird).
Another photographic theme that we have addressed for
our project was the self-portrait, conceivably the most taken
and published type of amateur photograph today. Figur 4
shows images of one of us, again at different times. Wann
recording these movies, we further decreased illumination
intensity for laser safety reasons. This resulted in longer data
acquisition and integration times (several minutes), requir-
ing the subjects to remain still. It is for this reason that some
of the movies from the portrait series show the slight motion
of the model. The necessity of laser safety goggles resembling
sunglasses is reminiscent of leisure, which is characteristic of
the selfie. The separation of subject and shadow is perhaps
most dramatic in this series of images, as it is now our own
shadow that is being detached. Metaphorically speaking, Die
shadow appears after our disappearance and fades quickly.
Heute, technology based on the propagation of light is ev-
erywhere (e.g. data transmission or the 3D reconstruction of
our surroundings in self-driving cars). And yet we are often
not aware of it, as our vision is not able to sense light in mo-
tion—nothing moves faster than the speed of light. To us, es ist
this close connection between time, distance and perception
that makes photography at the speed of light appealing for
artistic expression. Showing the movement of light across
familiar subjects and in ultra-slow motion requires us to re-
think common paradigms of photography.
Any image we perceive, even of a still life (static objects),
is the result of a highly dynamic process created by myriad
speeding photons—the quanta of light—that transport infor-
mation about the object toward our eyes.
Any image we perceive is necessarily an image from the
Vergangenheit, as it takes time for the light to reach our eyes. Photog-
Raphie (and visual perception) does not capture the moment;
it captures a moment from the past, the precise timing of
which depends on the distance to the camera (or the eye of
the observer). The positioning of the camera with respect
to the scattering objects determines which object is imaged
Erste. These notions are very familiar to astronomers; Wie-
immer, hardly anyone thinks about the nanosecond delays that
occur when we see ourselves in a mirror.
An object and its shadow do not coexist. They are sepa-
rated in time.
SEEC photography opens a new avenue for arts and pho-
tography, touching upon fundamental questions about our
visual perception, image sensing enabled by technology and
the nature of light itself. Light is the protagonist of our pho-
tographs, taking photo- (the Greek word phos means light)
-graphy (the Greek graphein means to write) back to its literal
Bedeutung.
Danksagungen
We acknowledge support from Mark Kasevich, Universität in Stanford, Der
Gordon and Betty Moore Foundation, TeemPhotonics and UC Berkeley.
Brannon B. Klopfer acknowledges support from the Stanford Gradu-
ate Fellowship. Philipp Haslinger thanks the Austrian Science Fund
(FWF): J3680, Y-1121. This project has received funding from the Eu-
ropean Research Council (ERC) under the European Union’s Horizon
2020 research and innovation program (grant agreement No. 758752).
Referenzen und Notizen
1 Ö. Rømer, “A Demonstration Concerning the Motion of Light,”
Philosophical Transactions of the Royal Society 12, NEIN. 136, 893–894
(25 Marsch 1677).
2 F. Krausz, “The Birth of Attosecond Physics and Its Coming of Age,”
Physica Scripta 91, NEIN. 6, 063011 (2016).
3 M.A. Duguay, “The Ultrafast Optical Kerr Shutter,” Progress in Optics
14 (1977) S. 161–193.
4 “Femto-Photography: Visualizing Photons in Motion at a Trillion
Frames Per Second,” Camera Culture, MIT Media Lab: http://web
.media.mit.edu/~raskar/trillionfps (zugegriffen 1 Dezember 2019).
5 One can see selected movies at www.seecphotography.com (zugegriffen
1 Dezember 2019).
6 E. Muybridge, Sallie Gardner at a Gallop, film (1878).
7 E.-J. Marey, “Instantaneous Photography of Birds in Flight,” Nature
26 (1882) S. 84–86.
8 E. Mach and P. Salcher, “Photographische Fixirung der durch Pro-
jectile in der Luft eingeleiteten Vorgänge,” Annalen der Physik und
Chemie 268 (1887) S. 277–291.
Manuscript received 2 Dezember 2019.
Enar dE dios rodríguEz is an artist whose interdisci-
plinary work includes photography, Video, websites, poetry,
installations and drawings. Her projects have been exhibited
internationally including at the Contemporary Jewish Museum
(San Francisco), Project Space RMIT University (Melbourne)
and Künstlerhaus (Vienna).
Brannon KlopfEr is a graduate student in applied phys-
ics. He received his BS in physics and minored in computer sci-
ence at Stanford University, after which he worked in industry
for several years before returning for his doctoral studies. His
interest in science started at an early age, playing with solar
cells and motors on the front porch.
philipp haslingEr is assistant professor at the Technische
Universität Wien. He received his PhD at the University of Vi-
enna in 2013 and was a postdoctoral researcher at UC Berkeley.
His research focuses on quantum metrology and the founda-
tions of matter wave interferometry.
Thomas Juffmann is assistant professor at the University
of Vienna, where he also received his PhD in 2013. He was
a postdoctoral scholar at Stanford University and ENS Paris.
His research focuses on optical microscopy, electron optics and
quantum measurement.
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