The most important rules of linear perspective are that objects appear smaller in the distance, and parallel lines converge on a hypothetical distant vanishing point.

In true reverse (or inverse) perspective, these rules are reversed, in that objects are larger in the distance and parallel lines converge in the direction of the observer’s position.

Reverse perspective is sometimes called Byzantine perspective because of its use in icon paintings, in which objects like thrones or platforms are depicted as wider on the portion farther from the observer. The notions that have been applied for explanation are that the important point of view is that of God, not of the human observer. Whether this is the actual intent is unknown, but it’s worth remembering that the invention of linear perspective postdates the Byzantine, so they could not have been using the reverse of codified rules they presumably didn’t have.

For those of us who have been exposed to linear perspective in images for all of our lives, the idea of reverse perspective is hard to visualize, but Jeremy Mooney-Somers has used 3-D graphics software (a modified version of Art of Illusion) to make an animated visualization of True Reverse Perspective.

I have to emphasize that the images above do not convey the idea. You must see the animated version to get the effect.

(It’s interesting to contrast this with with the Reverspective of Patrick Hughes; though not actually true reverse perspective, it’s an interesting variation on the way we perceive three dimensional relationships.)

[Via BoingBoing]

Researchers at the University of British Columbia’s Vision Lab recently turned their attention to Rembrandt’s incisive and justly famous portrait paintings in an attempt to identify the source of their visual power and appeal, and in the process, the techniques by which he commands your eye and directs it where he will.

It may not come as a surprise to artists who study such techniques that Rembrandt uses value contrasts, “lost and found edges”, and contrasting areas of texture to add interest, and grab and lead the eye; but the UBC researchers found ways to test the efficacy of the techniques by modifying photographs with some of the same characteristics and comparing the response to those and to control photographs without the specified characteristics.

You can read an abstract of their article, Rembrandt’s Textural Agency or the press release, UBC Researcher Decodes Rembrandt’s “Magic”, or download a PDF of the entire article, and see the gist of the techniques collected in a poster.

For a great resource on Rembrandt, see Jonathan Jansen’s Rembrandt van Rijn: Life and Work.

[Via BoingBoing, with a thank you to James Bright of Ottawa]

Sculpture, to be properly appreciated, must be experienced by moving through the physical space in which it exists, which changes your view of it until multiple views from various angles form a composite, three dimensional image in your mind (see my comments on Bernini).

Hughes creates paintings that change as you move past them, almost like the illusions created by lenticular displays, but Hugh’s illusions are based on a sound knowledge of perspective, both linear and forced.

He has created an intriguing method of using reverse forced perspective, painted onto angular three-dimsnsional supports, to allow the images from multiple physical planes to be perceived as a single image, the elements of which change their physical shapes and relationships when the viewer changes position relative to the work.

To get an idea of how this works, you must view his paintings in videos that change the camera’s position relative to the work, giving you the effect of walking by them. The illusion of unity is so remarkable that video is also the only photographic way you can grasp the dimensionality of the pieces.

There is a large video here, that starts with a brief exposition by Hughes before showing you the effect, a shorter one on his home page and another by a third party on Flickr that shows his remarkable piece, Paradoxymoron, that is in the basement of the British Library in London, from multiple angles. There is also a video of his accordion-fold “multiples” on his News page.

Hughes calls the principle “Reverspective“, meaning “…three-dimensional paintings that when viewed from the front initially give the impression of viewing a painted flat surface that shows a perspective view”. He even has scientific papers on the effect and a discussion of the perspective principles on which it is based.

The above images only hint at the process. View the video to see the effect.

Hughes’ paintings often make wry reference to other artists’ work.

[Via Digg]

In them he is exploring questions that are not raised often enough, including questioning the concept of exactly what is a primary color, and how might primary colors be interpreted differently; not just in different color spaces, additive and subtractive, but even within the familiar paradigms of modern color theory and practice.

The colors that are considered primaries, as he points out, are not set in stone.

The series, of which there are three installments to date, is likely part of the material Gurney is producing for his upcoming book, Color & Light.

I don’t know how many posts there will be in this series, but you may find that it encourages you to think about color and color mixing a little differently.

(You may find it useful to supplement your reading with my post on the History of the Color Wheel.)

Orosz is a graphic designer, illustrator, printmaker, poster artist, animator, stage designer and painter. He has a fascination with anamorphosis, and has several examples of his own in the gallery on his web site.

Unfortunately the site is inconvenient to deal with, one of those web site designs that is too “clever” for its own good (see my rant on How Not to Display Your Art on the Web). It opens in a pop-up, you have to wait for the white square to fill to indicate the site is loaded, and then deal with a difficult navigation system that is hidden until you roll over it and search out the links. Hints: main navigation is at the bottom, portfolio sections at the top, individual pieces in a band over the image in the center that you have to scroll through.

If you’re willing to work your way through, however, there are many interesting pieces in the section of Anamorphoses, along with illustrations, posters, paintings and Escher influenced etchings that explore the realm of impossible figures (see my posts on M.C. Escher and Andreas Aronsson).

You may find it easier to view Orosz’s work on Gallery Diabolus or Marlena Agency.

Orosz wrote an article titled The Mirrors of the Master in the book M.C. Escher’s Legacy: A Centennial Celebration.

Some of Orosz’s anamorphoses are particularly well done, in that the flat image makes perfect visual sense in itself, as in the image at top, with it’s anamorphic component hidden until revealed in the proper curved reflective surface (above, middle), as opposed to the somewhat easier paradigm of a flat image that simply appears distorted until viewed in the reflective surface.

Orosz also explores illusionistic double-images, as found in the work of Dalí and earlier artists, in which a secondary image can be seen in the main image (e.g. a face in a landscape).

I particularly like his poster designs, in which his playfully brain-teasing themes are presented in strong, simplified graphics.

These talks are almost always informative, entertaining and brain-ticklingly thought provoking. Some are on art (see my post on The Face of Leonardo?).

In this particular talk, Lotto utilizes several familiar but striking optical illusions (see my previous posts on some of them here and here), plus a few others, but goes beyond the usual concerns of the mechanics of vision into the questions of why we see as we do, why these particular illusions work, and how the way we see functions in our adaptation to the world.

The LottoLab site includes some articles and features on related subjects.

Much of the talk is about the nature of color, and in particular about a point that I often mention as perhaps the single most important thing I have ever learned about color, color mixing and color perception — that context is everything.

In his Glass Microbiology project he has created a series of glass sculptures of viral structures, to, in his words, “contemplate the global impact of each disease and to consider how the doctoring of scientific imagery affects our visualisation of phenomena”.

The sculptures are of viruses that are associated with particularly virulent and well known diseases, Smallpox, HIV, SARS, Swine Flu and, in the case of the image above (with detail below), E. coli.

The fact that the virus sculptures are made of glass, a transparent substance which, in its most basic form, has no color of its own, is indicative of the second aspect of Jerram’s investigation, the suggestion that the coloring of scientific images carries implications beyond conveying information.

It’s common for scientific images to be given false colors for the purpose of clarity, or easy perception of information that may be hard to glean in the images’ “true” state. An example of this might be the application of false colors to astronomical images to display the structure of nebulae or the light from infrared or radio sources.

It is also common to color images of viruses; in fact a majority of illustrations and images of viruses that are not the original electron micrographs seem to be intensely colored. Jerram speculates that as a result, most non-scientists might assume that real viruses are actually brightly colored.

He further speculates that the practice can promote a sense of wonder and and make the images more impressive (possibly intentionally), as well as carrying an emotional tone, perhaps one of menace.

The glass sculptures neatly obviate the effect of color (except for one that was deliberately colored by a photographer, though it acts as a contrast), and reduce the viral shapes to just that: their shapes.

Jerram has another interest in removing the effects of color and judging the effect on perception; he himself is colorblind (an awkward term that might more accurately be called limited spectrum color vision), though I don’t know in what range his limitation extends.

The play of light on these sculptures, however, is still beautiful, and the perception of the shapes is heightened by the refractive characteristics of glass (something I respond to as strongly visually appealing); so I have to submit that Jerram has removed one source of intentional visual appeal only to substitute another.

However, as sculptures they work wonderfully. The shapes of viruses are particularly fascinating forms. I also find it compelling that microscopic structures capable of being deadly on a devastating scale can be represented with such beauty.

Jerram’s glass sculptures will be highlighted in a solo show at Smithfield Gallery, London from 22 September to 3 October, 2009.

[Via MetaFilter]

All of my studies of color and color theory have led me to the inexorable conclusion that the single most important rule of color is that the human perception of any color is almost entirely dependent on adjacent or surrounding colors.

This is the basis of Eugene Delacroix’s wonderful quote: “I can paint you the skin of Venus with mud, provided you let me surround it as I will.”

While this principle is visible to the trained eye, both in painting and in life, it is never made more clear than in deliberately created optical illusions, like the e-Chalk color perception illusion I wrote about in this post.

This image shown here is one of the most striking illustrations of this principle I’ve seen.

I came across it in a post by Phil Plait on Bad Astronomy, who indicated the the original is from Akiyoshi Kitaokaâ’s optical illusion website (scroll to the bottom of the page).

Anyone with normal color vision will see a series of green and blue spirals. There would be little chance that a casual observer would suggest that the blue and green might be the same color, and yet they are.

You can see in the first detail image that the “green” spirals are only crossed by bands of orange, and the “blue” spirals are only crossed by bands of magenta.

In the second detail, you can see the Photoshop foreground/background color blocks where I have used the Eyedropper tool to pick one color out of the “green” band, and the other out of the “blue” band.

They are identical RGB values, 0, 255, 150. The same color.

The color is actually a green leaning toward blue. Richard Wiseman used Photoshop to change all of the values except the green and blue bands to black, and you can see a detail of the result in the bottom image. There is also a simplified version of the illusion here.

So the next time you’re looking at a color an think “that’s green” or “that’s blue”, well, maybe it is, maybe it isn’t, depending on the surrounding colors.

California born artist John Pugh paints large scale trompe l’oeil images, usually on the sides of buildings, that reveal impossible, and often amusing, dimensions to an otherwise flat wall.

In his Mana Nalu (power of the wave) Mural Project (image above, top, large version here) in Hawaii, the flat side of a building appears to be deeply concave, and filed with an enormous cresting wave, in which we see a personification of Queen Lili’uokalani. Riding the wave is pioneering surfer Duke Kahanamoku, and standing at the foot of the wave, looking for all the world like real children walking on a ledge in front of the oncoming wall of water, are three painted children.

Pugh likes to give our sensibilities an extra tease at times by including a painted observer in his illusionary scene.

In his Siete Punto Uno in Los Gatos, California (image above, bottom, large version here), a red jacketed woman peers into an apparently earthquake caused break in the wall of a cafe, that reveals a hidden temple of the Mayan Jaguar God (the bringer of earthquakes in their mythology).

Pugh’s web site showcases his mural work, public and residential and corporate. It also includes a page of “mural mishap” accounts, in which the illusion of the murals has prompted amusing responses from people, such as patrons in a bar who break glasses trying to set them on trompe l’oeil “shelf”, or people who walk into walls trying to walk “into” his paintings, a la Road Runner cartoons.

In addition to his site, Pugh maintains a site for prints and mural posters that also has galleries of images.

[Via Daily Mail Online]

He suggests that this is more than having a background knowledge of the artists or particular paintings, and in fact has to do with physical proximity to the painting, a reference to a kind of “sweet spot” from which the painting was intended to be seen, particularly in terms of being close enough to the image for it to fill a significant part of your visual field; but also, in some cases, requiring a vantage point from one side or the other.

A case in point is Daniel Vosmaer’s Delft from an Imaginary Loggia (image above, top), which looks “off” at first, but apparently resolves into a strikingly naturalistic scene when viewed from a position close to the bottom left of the painting. Some are more natural seeming in appearance when seen from a distance or in reproduction, like Adriaensz Berckheyde’s The Grote or St. Bavokerk in Haarlem (image above, bottom), but still evidently reveal their full force only when seen up close.

Gopnik goes on to suggest that over half the paintings in the show, and many other Dutch cityscapes, interiors and even still lifes, are meant to respond to an off-center point of view.

It’s a fascinating idea, and one I hope to put to the test by traveling to see the show.

When I first looked at the slide show in the Post of images from the exhibition, I was ready to jump in the car and drive down, because it looked as if Vermeer’s beautiful View of Delft (larger image here) was among the paintings on exhibit. I saw this amazing work when it was at the wonderfully extensive Johannes Vermeer exhibition at the National Gallery back in 1995, and I have been dying to see it again since. Unfortunately, that work was only part of the current exhibition in its other venue, the Royal Picture Gallery Mauritshuis, which is home to the painting. Apparently the curators at the Maruitshuis felt it was too dangerous to allow the large painting to make the trans-Atlantic voyage again, as explained here.

Still, the current exhibit of Dutch cityscapes, from the height of their glory, should be something to see indeed. The exhibition contains 48 paintings by over 40 Dutch masters, including Gerrit Berckheyde, Aelbert Cuyp, Jan van Goyen, Jan van der Heyden, Pieter de Hooch, Hendrick Vroom, Pieter Saenredam, and Jan Steen; and is supplemented with maps, atlases, illustrated books and prints.

Pride of Place: Dutch Cityscapes of the Golden Age is on display at the National Gallery in Washington until May 3, 2009.