Left: arrangement for a projection of the face for a self-portrait; Right: set-up for a projection for a portrait including more of the body, where the image is smaller (all images courtesy Francis O’Neill et al 2016 J.Opt 18 080401) (click to enlarge)

A new study of Rembrandt’s self-portraits provides more evidence to theories that the 17th-century artist, among other Old Master painters, used optics to produce his remarkably accurate works. Researchers Francis O’Neill and Sofia Palazzo Corner recently published their paper in the Journal of Optics that explains how various setups of flat and concave mirrors, all widely available during Rembrandt’s time, may have created projections the artist could precisely trace.


Diagram of set up for life-size self-portrait projections, where the artist would stand at 2× the focal length of the concave mirror, which is equal to the sum of the distances between the concave mirror and flat mirror, and the flat mirror and projection surface. A clear, life-size projection was achieved using a 10 cm diameter mirror with focal length 100 cm (click to enlarge)

The pair’s research builds on David Hockney and physicist Charles M. Falco’s controversial hypothesis of 2001, which claimed that artists since the Renaissance used optical devices from curved mirrors to the camera obscura to achieve realistic images. O’Neill, himself a painter and art teacher, spent the last decade examining Rembrandt’s paintings; with Corner, an independent physicist, he fiddled with mirror arrangements to identify the positions and distances that would concentrate light in a way to produce projected images of himself similar in scale to Rembrandt’s self-portraits. In the diagrams, light reflects off the mirrors in a zigzag pattern, landing on a projection surface that had to stand within arms-length of the artist. Rembrandt’s choice of material, the researchers say, suggests that he did employ such setups with optics.

“The earliest of Rembrandt’s self-portraits are striking for the level of detail accomplished in such small images,” the pair writes. “A number of these smaller self-portraits are etched onto copper, a surface upon which projections can be seen extremely clearly. Two early painted self-portraits are also made on copper—an unusual choice of surface for a painting, but perhaps telling of an artist working from a projection.”

The researchers examined several other common aspects in the Dutch artist’s works such as his off-center gaze, which they say may suggest he was facing a projection surface off to the side rather than looking directly at his reflection in a flat mirror. Projections would also likely enable him to paint more lively poses — such as of himself laughing — as he would be able to freeze his entire facial expression while tracing the projected image, rather than moving slightly as he worked between mirror and canvas. Rembrandt’s use of chiaroscuro, the researchers say, may also have been a byproduct of his projections, as the technique’s necessary, precise lighting conditions would have created “an image with strong light-and-dark contrast.”

Rembrandt, "Rembrandt Laughing' (1652) (image via Wikipedia)

Rembrandt, “Rembrandt Laughing’ (1652) (image via Wikipedia)

One of the paper’s particularly interesting propositions is that Rembrandt’s portraits increased in size overtime as he was increasingly able and more willing to invest in larger concave mirrors with greater focal lengths.

“His ability to maintain the realism and detail of his smaller, earlier images as well as the sheer scale of his later self-portraits, is what remains so striking,” the authors write. “In a simple, flat-mirror reflection, the distance from artist to mirror required to achieve visibility of the torso, let alone the whole body, would leave the details of the face and hands difficult to see, as the reflected image would necessarily be formed at a distance that precludes such close scrutiny. The further the reflected image from the artist, the greater it appears reduced in size, and yet, in his late works, Rembrandt consistently paints himself at a minimum of life size.

“The use of concave mirror projections enables the artist to be close to the projection of a life size composition, and hence able to observe the details of his features, albeit in the soft focus of the projected image.”


Diagram of set up for a self-portrait projection using a single concave mirror, which allows for the projection of profile self-portraits. This method may have been used by old masters such as Durer, but not by Rembrandt

According to the New York Times, Falco apparently praised O’Neill for his work; optics expert David G. Stork, however, who staunchly rejects the Hockney–Falco thesis, remains unconvinced, stating that no historical documentation exists as proof that optics aided Old Masters.

“People have accused me of being jealous, or trying to discredit Rembrandt, but that’s not at all what I’m trying to do,” O’Neill told the Times. “If you gave a projection to someone on the street and told them to make a masterpiece, they would never give you a Rembrandt.”

Just as scientists at the time used lenses to better understand previously unseen natural phenomena, the researchers argue, it would follow that artists, too, likely would have taken advantage of the technology to view their own position within the world.

Claire Voon

Claire Voon is a former staff writer for Hyperallergic. Originally from Singapore, she grew up near Washington, D.C. and is now based in Chicago. Her work has also appeared in New York Magazine, VICE,...

21 replies on “Evidence Mounts that Rembrandt Used Optics to Paint Self-Portraits”

  1. The concave mirror seems unlikely just because the largest known such mirror in a reflecting telescope during Rembrandt’s lifetime was only 7 inches across. And yet he had one that must have been several feet across?

  2. Any theory that originated in part from David Hockney must be suspect, he who “since 2009 . . . has painted hundreds of portraits, still lifes and landscapes using the Brushes iPhone and iPad application. . . .” (Wikipedia), and, in prior years, various other technical devices. The great Rembrandt’s dependence on mirrors would go a long way in validating Hockney’s work, but we must wait for a consensus of recognized Rembrandt scholars before taking Francis O’Neill’s current theory seriously.

    Louis Torres, Co-Editor, Aristos (An Online Review of the Arts), and Co-Author, ‘What Art Is: The Esthetic Theory of Ayn Rand’ (Open Court, 2000) –

    1. Any counter-argument based upon ad hominem and an equally flawed, albeit dogmatic, esthetic philosophy (Rand’s) are no less suspect.
      If one is to take a truly Randian path, one need only assert that there simply is no real incontrovertable empirical evidence of the use of lenses or mirrors. The presence of them in the world does not constitute proof. There is no ‘objective’ evidence that cannot be readily attributable to other cause.
      Hockney’s argument cannot be validated and has not been validated because of one single critical flaw; it simply does not constitute proof, no matter how earnest its proponent. It remains pure speculation.
      This has absolutely NOTHING to do with Hockney as an artist. Asserting so only adds disingenuity and hubris to the discourse.

  3. How could this possibly matter? One’s ability to convert 3d to 2d speaks nothing of art but of craft. Composition, color, interpretation, is what makes Rembrandts great for their day. His anatomical accuracy is what makes them weak for our day. There are many Davinci sketches for his works. They are loose contour sketches. Unlike the refined, filled in, sketches we are most familiar with. I propose that these sketches were the true birth of impressionism. If only Davinci presented them as “finished work” rather than irrelevant studies. Here’s a piece I did compositing these sketches.

  4. Of course it matters… Knowing more about all the materials an artist uses — brushes to lenses — helps us understand that artist’s achievement. It does not diminish Rembrandt to suggest that he used optics. But it does mean that he was human. And this study adds force to David Hockney’s convincing book, Secret Knowledge. Hockney is, like Turner and Constable before him, a member of the Royal Academy, where he has an exhibition of portraits through 2nd October 2016. You need to see the work before you say any more…

  5. Have any of these theorists tried painting from a reflected image?

    Considering the lighting and lenses/mirrors available in Rembrandt’s time, I can’t help but wonder if a skilled artist could produce better work without the mechanics. There are extraordinarily talented realists painting today whose work is as accurate as Rembrandt. Do they use mirrors or projected images?

    1. I go with the skeptics. This theory might work, as far as the optics and pictorial rendition are concerned, and that is an intellectual achievement in itself. However, this is not enough to establish/prove that Rembrandt ever used such methods. There would have to be some trace of these complex set-ups in his sketches and drawings, and yet (to use an analogy) even these show hardly any evidence of the use of formal perspective techniques in composing his pictures (see, for ex. Ben. 545).

  6. During Rembrandt’s lifetime, art and science often collided as technology advanced, and mirrors became more widely available and less expensive. To put it simply the arts has always had a close relation to science technology, curious I may say as artists looking for things that could help enhance their exploration of enabling them to make their art as what they see in reality.
    Other than Rembrandt, I have always looked closely at other artists’ works from the 1400’s through the Renaissance to the present. I have a degree in art and art history, having taught art for University/College mostly and I have myself used devices from the old slide projector to the computer age tech to explore and use to create my artwork. They are all tools, as is the brush, and to each their own feeling on it. It’s much about what one enjoys exploring, in the process and thus fascinating new results.

    I had always admired and studied Vermeer, and knew early on his artwork had a radiance and proportions that some other artists did not. I often though artists like Caravaggio also had used some optical device, as Vermeer used the Camera Obscura. I could make a list, but these artists say much about the growth of very realistic compositions. One thing also struck me was that the output of many artists after 1600 was more than many prior.

    Instead of the flat mirrors that are common today, many mirrors were convex—bulging outward toward a light source. Concave mirrors also appear to have been available. During Rembrandt’s time, though, flat forms evolved, and the master may have been able to afford more and better mirrors as his career flourished. At the same time, lens making was booming, enabling the development of things like camera obscuras and telescopes. It seems that the size of these mirrors developed also, as science and the capacity to develop them bigger was not that difficult and they were made to be used for more than just telescopes. A demand came for mirrors to be used for wealthy families to add distinctness in their homes.

    Something to note, is that prior to Rembrandt’s time, the use of glass with a metallic backing commenced in the late 12th and early 13th centuries, and by the time of the Renaissance, Nürnberg and Venice had established outstanding reputations as centres of mirror production. The mirrors produced in Venice were famous for their high quality.

    Venetian workmen succumbed to the temptation to carry the secrets of their craft to other cities, and, by the middle of the 17th century, mirror making was practiced extensively in London and Paris. Generally, mirrors were extremely expensive—especially the larger variety—and the wonderment created at the time by the royal palace at Versailles was due in part to the profusion of mirrors that adorned the state rooms.
    There seemed therefore to have been much time for larger mirrors to have been available in Rembrandt’s time.

    1. With all due respect for you and your own studio practices, that you or any contemporary artist uses such technology in the creation of your art does not immediately translate as an effective argument that past artists had done the same. Likewise, the presence of the means to do so is by no means proof that any artist past artist used such lenses and mirrors to create their images. There are many many examples of past and present day artists who did/do not use such devices yet are capable of and do readily create stunningly accurate and details renderings without such aids.

      1. I can surely agree that most of the artists from the 1400’s onward, did not use any optical devices. Most who were trying to capture realism, as I’ve done, used keen perception,visual measurement to create quite accurate representations of their subject matter. It is much practice to do so, and what comes out is the artist’s expression, feeling into the artwork.

        Also I can certainly agree that creating using a natural traditional manner to paint can produce a stunning art with accurate detail/proportion without devices. But curious as us artists are, and
        often not always wanting to labor over many weeks painting one piece of art, often they’re tired of representing every needle on a pine tree, so one may develop their style into less, using shapes, forms and lines that are quite minimal, but the viewer fills in the rest looking for more.That is my style fusion, of colour-field, minimalism and expressionism. Back in Renaissance era on,things were labelled easier. Now there’s more styles in art, and new technologies, are simply tools.

        There is some proof, much from scientists of the past of optical use. Now I can talk about Joannes Vermeer, as similar to Rembrandt, Van Eyck, Caravaggio mostly. Now I keep in mind that
        the artists who used optical devices in my view surely used them partly to get a best proportion; did the rest by hand eye to subject. I’ve done this with a projector quite awhile back just to get that outline, then the rest was left to do by hand. I realised from my experience, not to say how I did them,
        my theory about the artists who could have used optical affects, likely did not want this ‘secret’ known, as then others would emulate and maybe some felt people might not like that they were done using an aid to create their art.

        I wondered how Rembrandt could have produced so many paintings that were quite accurate. I saw his art at the Amsterdam’s Rembrandt Art museum. I was so used to his work art book images, then seeing many of his
        paintings small, it did surprise me. Also as I looked around the walls, his works had such as similar look, mostly portraits same palette colours fairly much. I realised many painting were roughly 14″ x 12″. I assume it took less time to create and if he employed an art aid, that made for more art producing. The one interesting aspect of Rembrandt and Vermeer is that most paintings were done inside and many times in the same place, with some things moved around.

        Essentially Vermeer and somewhat true with Rembrandt, Vermeer was really more interested in the technical, the structure, like a scientist. Every painting is so accurate, much similar, like no one else I’ve seen prior to 1900,
        and like a photographer, he moved his ‘props’ around, got the right lighting set up and as proof of where he painted, if you see, many of his works have the same diamond floor tile. Now, there is little emotion to the ladies posing, no smiles really, a bit dull, -they posed for long periods as written. Even though they are so realistic, that’s what mattered to Vermeer; the ability to capture light, shadow, proportion, so the technical aspect of his work is truly brilliant, but for feeling, his work does lack expression, which a photo can do.

        In comparison i would say Rembrandt’s artwork has is more expressive. Now let’s say he used a mirror device, I would feel Rembrandt would have used it only enough to capture/outline a bit of person’s outline proportion and some body/facial contours. They are different in their styles. I do prefer Vermeer’s personally. For me, it’s the subject matter and colours.

        Now, I’ll use the evidence in a Vermeer painting that relates to what a camera sees, as the best evidence of optical use, since there’s not enough documentation by more artists saying they used optic devices. Let me just
        name similarities of what is seen in his paintings as what a camera sees,and on film produced looks like. Both have often curved surfaces, light and shadow make for chiaroscuro effect, the errors in perspective, mid-ground figure looks bigger than figure near, in background from wide-angle effect. There’s the dark background and compression of foreground, middle and back as flatter space, soft focus background which our eye doesn’t see, as when looking into a room all things are focused. Natural painting by most artists most often all elements are in focus, no matter the distance, as how we see reality. One thing to note is in one or two of Vermeer’s paintings, a mirror reflecting the head of a person at back is the right proportion naturally. A camera picks that up. I recall in taking early to high Renaissance art history, on proportions; that so many artists then made the error in creating a reflection of people, but wrong proportions. They were not being attentive,as if one studied reflection and subject closely, the two would be different scale.

        As far back as 1434 they saw things like eye spectacles, magnifiers, mirrors, some even showed up in early paintings also, but no thought then to use these for artistic tools. But as in all fields of study, there has always been the
        geniuses that did think beyond the common methods, to be innovative. As with my studies with an art history and history degree, Time and time again when there has been the fusion with art and science. They work together.

        Just look at if Steve Jobs, who was not just willing to make the computer just a better typewriter, to do things faster, he was relentless, as he saw creative possibilities ahead of the times, as focused on what could it do creatively. He was a “creative genius” who “changed the world” in many ways. In addition to Jobs, plenty of great minds have challenged paradigms, opened windows into worlds we didn’t even know existed, and produced innovations that have persisted through time. Look at the world’s titanic thinkers, from Charles Darwin, Edison, Nikoli Tesla, Albert Einstein to Stephen Hawking.

        But it was not until the high Renaissance with the sudden spirit of scientific theories, technical devices, as the telescope blossomed, that also artists became interested in experimenting with them. literature kept mentioning
        Vermeer’s experimentation with optics and painting. In the same breath with the microbiological work of Van Leeuwenhoek,
        who just so happened to live just a few blocks from Vermeer and notably met each other. His pursuit of “the optical way” of seeing and painting paralleled methods being developed at the time by figures like Leeuwenhoek an early microscopist who discovered ‘bacteria’ and who could have shown the artist how to use a camera obscura. Vermeer used optical instruments to
        expand the way he perceived and depicted reality. The camera obscura was a small, darkened cubicle, onto whose wall the artist would project, via a lens, various studio scenes in order to capture ‘photographic’ effects such as focus and blurring.

        Like van Leeuwenhoek, who kept viewing his subject of bacteria, under the microscope again and again in different lights to find things he had missed before. Vermeer kept returning to the same composition elements in the house interior with a table and human figure, achieving subtle new effects in lighting, color, shadows and focus.

        Leonardo Di Vinci is known to have used optics and had written thesis on them. Mona Lisa is captured in a softer light with features that look less traditional than that of girl. Much is the same with Vermeer’s subjects. By comparing almost all of his paintings, the women’s facial expression strikingly don’t show any personality. It shows that Vermeer had much more interest in the technical aspects of the artwork, the refinement of proportions, shadow to light exactness. It comes down to his high interest in being like a scientist. His themes are so similar, one cannot mistake a Vermeer painting.
        He used much the same area in the house, as trying to discover more about the lighting, shadow, and there’s many things I noticed long ago in my interest in Vermeer.

        One aspect were these ‘dots of light’ soft or not so, that were the high point in light reflection, one’s eye in natural painting would not see. In my study of many artists, I had yet to see any that had that painted in those ‘dot light reflections’, which can only come from the use of optics, as mirrors. I see them when I take a photograph. One just discerns them simply looking in a room. Looking a Vermeer’s more famous ‘Milkmaid’ lady, one will notice this ‘dot reflection’, like halo effect on the basket,the bread and the milk
        jug. Vermeer would not have been able to see that with his naked eye. Also compare the basket in the foreground with that at the top. The one at foreground has been painted out of focus or in soft focus. Moreover, the flowing of the milk seemed to have been captured at the right moment. Looking at images through a lens would produce that effect.

        At the end of the 16th century, when lenses were first used by painters, there were two noticeable traits about the new images. First, the subject seems much further to us, the viewers. Secondly, odd to say, there was a sudden increase in left-handed drinkers depicted in pictures. This is exceptionally unusual given that most people – both left and right handers – tend to lift a glass with their right hand due to glasses, cups are usually set to the right at dinner. This could be explained by the use a lens whereby the artists simply
        painted what they see in the projected image.

        On the rare occasions that the general public do get to see his art at auctions, most would marvel at the resemblances between his
        paintings and modern photographic prints. With the invention of photography in 1839, interest in Vermeer’s art rekindled. In 1866, Theophile Thore
        published a catalogue of his known oeuvre, and in 1891, a first public identification of photographic traits in Vermeer’s painting was made by the American lithographer Joseph Pennell, in the British Journal.

        With over 200 years of speculation, study and evidence fairly enough, it is my view that, as history repeats itself, that Vermeer, Rembrandt
        to Di Vinci used tools as mirrors and lenses some more, some less to work on their art. As artists like scientists are interested in each other very closely, as science is also about technology, the creative mind is there to be with the analytical minds, and that’s one fascinating reason we have had so much technical development increase rapidly in the last few centuries, partly in order to be innovative, creating better and more efficient, effective technologies.

        1. Mr. Peltonen;
          Wow, that is quite the essay. While I think that for the most part we are on the same page, this writer does think that evidence of the use of optical devices has been largely exaggerated, this especially so by Hockney. Unlike some, I do not choose to disparage Hockney the artist. His art is his art and has little to do with the discourse on the use of said devices.
          Unlike [some?] who may use such devices in the present as a means of projecting and then tracing, historical use is/was more of a compositional tool as opposed to one as an aid to accuracy. Vermeer however shows much more empirical evidence in that his images show more the effect of optical phenomena. This especially so in highlights. But save for him, such evidence in others is weak.
          As for the evolution of the painted image an a focus upon the phenomenology of painting and interest in the abstracting that optical experience, I heartily concur. In this respect the artist has assumed the role of scientist and art has evolved into a search into the nature of things as well as the expression of that search – an endeavor far more gratifying for this writer than mimesis, documentation or vague expression of the notions ‘beauty’.

          1. Yes, I feel we’re much on the same page. I did get a bit carried away, in essay style [instructor syndrome], was to be a mini-essay.

            Vermeer interested me a long while back, when I was reading about artists and art history, as realism was the focus for me. With my initial desire to travel through Europe and N. Africa, I followed the ventures of artists knowing I’d come across where they lived.I think I’ve now been to Holland six times. I did also see the Van Gogh art museum, which was happily intense. Rembrandt, who has made me yawn at times, I do however enjoy some of his brooding brown tonal colour portraits, even thought I am not a big fan of portrait artists. He tended to play it ‘safe’ kind of; nonetheless a master artist. His self portraits do have a lot of character and expression. There however are a good number of artist exceptions, as the one’s that painted other subject matter.

            I do believe very much that young students as artists need that development of the eye, of perception, seeing what is there, and not what the left hemisphere thinks it is supposed to be. Practice by ear in music, before taking to the notes helps to not depend on one method. Same in learning art with a keen focus; just the paper, pencil and the knowing what it is one is actually perceiving; as with Vermeer, it is that understanding of the relationship of shapes, forms, lines, angles, then the placement of content.
            Be well. Thank you for having me ponder deeper and learn from your point of view.

  7. What do we really know about Rembrandt’s studio practices or his assistants? There is a confluence in the Netherlands when Rembrandt was there that would certainly impact his work and his processes. This all might fly in the face of what we would like to believe about him and any artist in any time. Room-size Camera Obscuras were known at least in the Renaissance and probably much earlier. Mirrors and lenses were around long before that but not perfected until the time periods in question.
    His self portrait paintings are much more than renditions of likeness and that comes from a place other than reflected light.

    1. ‘Self- reflection’ has its own accuracy…not necessarily confined to the eyes or optical felicity.

    1. Evidence for Vermeer’s use of the camera obscura is far more compelling than just about any other artist in history. Though, Teller’s book and video are no more particularly valid than is Hockney’s.
      Furthermore, this use by Vermeer is not so relevatory, having been largely accepted long before Hockney. It is not that Hockney is totally out in left field. Yes, certainly optical devices have been used. It is the pervasiveness of that use that is truly at question. In addition, these devices were not quite so very common, and were relatively cumbersome to use and require a darkened space (studio) to use. Some seem a little confused about the contradictions of 1) the mechanics of projecting a view-able image, versus having the means to paint/trace that image from said projection. A room dark enough to project is also too dark in which to accurately match pigment color to image colors.
      Again as this writer stated in other comments, the ability to render accurately without said devices is not an altogether uncommon skill. It is and was readily done without these devices.

      What is ignored in this and Hockney’s argument is the artistic fascination with the science of optics and the explicit exploration of the associated phenomena as the subject itself of the art. The preponderance of evidence cited by Hockney as a reliance upon devices may in fact simply be an expression of the artists’ observations of that optical phenomena. The evidence for this is far more substantial.

      1. I’ll leave it to the experts to decide. The notion amongst purists that technology assistance in the art makes it less art is the misunderstanding here. Not that technology may or may not have been used.

        …as an example, a self-portrait requires a reflective surface. Technology. Improvement in brushes, colors and paintable surfaces also are technology.

        1. Concur…however, that Hockney repeats his message over and over does not constitute proof of anything other than his earnestness, likewise the availability of a certain technology is by no means proof of its having been used for a certain purpose.
          We have proof positive of the use of brushes, pigments, supports formulas et al. It is odd that we have little if any empirical evidence proving that Rembrandt used lenses and mirrors – None, that is, other than that these devices existed. And, THAT is issue that this writer has with the entire argument.

          In a universe at that time where many, many were so focused upon on objective observation of ‘ the world’, virtually no one documented this use in their oeuvre. This absence seems quite idiosyncratic for an artist as sensitive and observant as van Rijn, especially in his self portraits, which become all the more honestly and candidly descriptive as the master aged.

  8. So sad. Anyone else remember Chariots of the Gods? It was an attempt to prove that the pyramids, etc. were built by technologically advanced beings from another planet. O’Neill is working the same dubious vein. And, unlike Hockney, he is actually a fairly gifted painter.

  9. While one can appreciate Hockney’s earnestness, his empirical evidence is more than a little lacking.
    Likewise for the author of this article, who seems all too willing to jump on the bandwagon. The “mounting evidence” is not evidence at all. That the technology existed enabling its use, is by no means evidence that so many artists did indeed use lenses, mirrors et al. All evidence is circumstantial and frankly speculative, absent of proof.
    What is more critical to the discussion is that in a practice so dominated by visual documentation and images of everything from the artists’ intimate moments and details, there are so very few showing this use, nor is there much if any written documentation. rather odd for a discipline practiced by so normally obsessively observant practicianers.
    Most informed artists and art historians will readily acknowledge that the big secret about the art and artists is that there really are no big secrets. No secret devices, no secret formulas. Artists can and do create very detailed and accurate renderings, have so for a long time.

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