It's been a quieter than usual month here on Symbiartic, but rest assured, both Kalliopi and myself have more fascinating images and stories from the intersection of science and art to share. Today I'd like to kick off a new series of posts about science and fine art history by looking at one of the most respected paintings ever made, The Ghent Altarpiece, aka Adoration of the Mystic Lamb .

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Realist painting from the Renaissance can feel imbued with mysterious and powerful presence. These paintings have endured time, scrutiny and use techniques few people understand. I think the combination of unfamiliar, complicated, yet centuries-old technical knowledge can seem almost magical to those who have not studied it.

I've discussed oil painting techniques a bit before here on Symbiartic, (The Chemistry of Oil Painting, August 2011) and like any knowledge, pulling back the curtain on oil painting techniques can raise the appreciation of art work more than leaving it mired in mystery. The Ghent Altarpiece (1432), by the Flemish brothers Hubert and Jan Van Eyck is one of the most stunning examples of oil painting in the world. And new technology, available freely online to study made my jaw drop.

When I was doing my fine arts undergrad, I remember discussion of how standing in front of the real painting, there's almost an aura about them, like standing with a real person instead of a photograph. Technology, the image of an image, is pre-supposed to separate us from the real image. But sometime sit takes us closer.

I've never been to Europe (yet). Even once I one day make it there, it's unlikely I'll ever get as good a look at The Ghent Altarpiece as I now can from the internet.

A new project, called Closer to Van Eyck came online earlier this year. In brief, the site, coordinated by Ron Spronk of Queen's University, contains incredibly high resolution images of the Ghent Altarpiece polyptych - and the zoomable macrophotography is complemented by views in infrared macrophotography, infrared reflectography and x-radiography.

Here's a look at the crown of god , the macrophotography one step away from full zoom, and the infrared macrophotography to match:

Using these three other views can reveal more than just fine detail; clues to the techniques employed by the brothers can also appear, if you know what to look for. But I want to focus on what's visible at high zoom under normal light. Let's take a look at the glints in the jewels.

Reflected light is a tricky thing in painting. There are some modern masters such as artist Jeff Hayes who spend years exploring the way light bounces off of surfaces, and how to re-create those effects using pigment and oil. In the image above, at first glance the Van Eycks seem to have simply used daubs of white paint for light reflections off of the jewels. Let's take a closer look, at that main red jewel.


Note: I've lowered the resolution in Photoshop to help the blog load quicker: for super-full-amazing detailedness, make sure to go to the actual site.

For the most part, the colour is white, possibly something with some zinc in it which tends toward the yellowish whites. The plainly yellow daubs around the pearls may have yellowed with age (linseed oil in particular yellows, darkens and becomes more transparent with age - a dark background under the white daubs would start to show through discolouring them further). This is armchair speculation on my part - an analysis of pigments used by the Van Eycks was also no doubt part of the restoration and preservation of the Closer to Van Eyck project.

On the right-side of the jewel, we can see a streak of an orangey red alongside a white streak. Although a somewhat rusty colour up close in fig.2, from a greater distance in fig.1, the white almost seems invisible, and we see a stronger, vivid orange glint on the right-hand side of the jewel. The rusty red + thin white streaks merge at that distance and appear as a brighter orange. Amazingly, at both distances, they seem realistic despite visible brushstrokes.

Zooming in on these glints in the Ghent can reveal further surprises. Modern Art Notes blogger Tyler Green reports on the discovery that one of the angels is sporting a brooch with a blue jewel, reflecting not just light, but a reflection of a complicated window frame from inside the chapel where it is installed which was likely painted after the rest of the painting was complete.

The colours employed in a jewel's gleam also matter. Note the use of the three primary colours in the reflected gleams in this dark jewel at the center of Mary's crown:

And from a distance...

...our eye (and the camera's lens) read the colour as white.

New technologies and investment into exploring and preserving fine art from centuries past yields not only new understanding, but also new wonder. The whole crew of the Closer to Van Eyck project and its support and the work by the Getty Foundation have raised the bar on this amazing work higher than seeing The Ghent Altarpiece solely in person ever could.

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