'Secrets of Leonardo revealed'?

October 1 2014

Video: BBC. Images: Copyright Pascal Cotte

There was a slew of stories in the press yesterday on the 'secrets' revealed by new analysis of Leonardo's Portrait of Cecilia Gallerani, better known as the 'Lady with an Ermine'. Above is the BBC news piece. Here is the Guardian's report. And here is the LA Times.

Pascal Cotte (seen below, with a model recreating Cecilia's pose), co-founder of Lumiere Technology in Paris, has analysed the picture using a 'layer amplification method', or 'LAM' which, he says, allows us to peel back the layers of Leonardo's painting to reveal how he made it.

Cotte says, in a new book 'Lumiere on the Lady with an Ermine' (available here on Amazon), that Leonardo painted the picture in three seperate stages. First, the portrait was made without an ermine, with the sitter's right hand as shown below.

Then the ermine was added, but with a more slender form:

And finally, the bulkier ermine was painted on top of the first ermine, and that is the picture we see today:

The famous Leonardo scholar Martin Kemp seems to accept the results wholeheartedly, and says that they:

[...] tell us a lot more about the way Leonardo’s mind worked when he was doing a painting.

“We know that he fiddled around a good deal at the beginning, but now we know that he kept fiddling around all the time and it helps explain why he had so much difficulty finishing paintings."

But unfortunately, it seems to me that this is yet another example of the over-interpretation of technical analysis, in this case mainly various forms of multi-spectral photography.* Regular readers will know that I have been sounding warning signs about this for some time (see an earlier example here over Rubens' portrait of Van Dyck). We must be wary of too much messing around with things like Photoshop.

First, I must state that Cotte's work is a valuable contribution to art history, and his technology can yield some fascinating results. He featured on an early episode of 'Fake or Fortune?', and his work with Professor Kemp on the so-called 'Bella Principessa' - the newly discovered drawing which Kemp attributed to Leonardo (but which has so far failed to find favour with the majority of other Leonardo scholars) - raised many interesting questions that were perhaps unfairly tarnished by Peter Paul Biro's 'Leonardo fingerprint' controversy (see the Cotte/Kemp Principessa book here, and further AHN on the matter here).

And Cotte's analysis in the case of 'Lady with an Ermine' does indeed reveal some interesting facts about Leonardo's approach to the painting. We can see in the image below, for example, that Leonardo made a number of changes to the dress, including in the detail on the sitter's left arm - the intricate scroll pattern appears beneath the red layer we see in the finished painting, and echoes that seen on her right arm.

Another interesting detail is the obvious change in the outline of the ermine, as seen below, which is a classic example of the sort of artistic change, or pentimento, we can now see easily with modern IR photography.

However, Cotte's central thesis, that the ermine was an after-thought, is not, it seems to me, actually evident in the images he has published. For example, Cotte says that the four ghostly shapes below are evidence that the sitter's right hand was originally perched on her left wrist, just below where the ermine sits in the finished picture:

In this image below he has highlighted the 'fingers' in purple: 

But these shapes, noticeable only by enhancement, could really be anything; something in the make up of the panel, a variation in the application of ground layer, or a more minor change relating to another area, and so on. The shapes are not nearly obvious enough for us to deduce that it was once a hand.

In fact, here below is a zoomed out image of the same area - taken from another of Cotte's scans - and it seems to me that in fact a whole different shape can be seen there, just above the 'fingers' identified by Cotte. These too look like they could have been fingers - but Cotte makes nothing of them in relation to the hand,  even though they appear to be the same consistency and type of form, and says instead they are part of the tail of the first ermine:

In the image below I have (very inexpertly) pointed out the area I'm talking about with a red arrow. Cotte's 'fingers' are pointed out with the purple arrow:

The point is, it's possible to look at scans like this and imagine all sorts of shapes and features, be they fingers or imagine tails. In any case, can we really believe that Leonardo, the master of almost lyrical anatomy, would ever have concieved such an awkward pose?  

I am equally unpersuaded by the idea that there were two different ermines, one thinner and another that we see now. Again, there is not enough evidence to prove that the ermine was originally the oddly shaped creature Cotte claims it to be. I don't believe Leonardo would paint such a thing - it looks like one of those draught excluders you get in Poundland.

I am truly sorry to rain on Pascal Cotte's parade like this - especially after he has kindly shared his press images with me. Of course, you can all feel free to ignore everything I've said here. But there is an important point to be made about interpreting the technical analysis of paintings, which is a science in its relative infancy.

In these cases, I always mention the cautionary tale of the certain yellow pigment - I forget which - that scientists assured us was not invented till the 18th Century, leading to the rejection of a number of pictures as later copies. Only recently was it discovered that this pigment had in fact been around in the 17th Century, and that the rejected pictures weren't 'wrong' after all. The point is, those undertaking the technical analysis of pictures have not yet built up a deep enough body of evidence to enable to us to say with certainty, 'this pigment only dates to this date', or, 'this is what a Leonardo pentimento of a hand looks like'. To make such conclusions, we must first test far more paintings, so that we can build up a truly reliable database of yellow pigments, or scan every Leonardo painting to be sure what one of his hidden hand, if we can discern such things, really looks like. Leaping to conclusions from such a small sample size would not be acceptable in any other science.

We, that is the public, art historians and the media, are in danger of placing far too much faith in the analysis of difficult-to-read images by scientists who may not be familiar with all the vagaries of how artists worked. It's curious that while many art historians denigrate one form of connoisseurship - that is, the close analysis of a picture's surface to learn who painted what, when, and how - they seem happy to accept unquestioningly a different and far harder form of connoisseurship; the analysis of what lies beneath a painting. It's also curious that we seem happy to outsource this art historical analysis to scientists, who may be very qualified to take the sort of photos Cotte has taken, but are no more qualified to analyse them the man in the street. But then there is a general perception that science, being a binary discipline, must be right. I would argue that, when it comes to pictures, it isn't. At least, not yet. 

Update - a reader writes:

To me the ghostly image you point out with the red arrow looks just like an eagle (in profile, looking right). Do you see it too?


Another reader reminds me that Brian Sewell doubted whether Leonardo painted Lady with an Ermine.

Update II - And because I was quite pleased with it at the time, here, in case anyone's interested, is my review of the National Gallery's exhibition on Leonardo's Milan works, in which the Lady with an Ermine was shown.

Update III - another reader writes:

It is well established that Leonardo fiddled with his paintings and completed them slowly

The significant changes in the ermine were accompanied by changes in the dress and elsewhere and are logical to imply a robust duke.   The x-ray and infrared images add to the understanding of his process and the scientific analysis reveals are some of these changes

But one must view the less clear images as suggestive and  with the same uncertainty as unclear images of alien ships and imaginary creatures. They are subject to interpretation and the objects might exist but require further confirmation.

Update IV - Pascal Cotte has kindly been in touch. He has asked me to point out that I have not read his book, in which he goes into everything in great detail. I'm more than happy to do so.

He also makes the following points:

The  L.A.M. technique provides images from deep inside the layers of paint. So it is easy - by comparison - to check if we are wrong or not. I can demonstrate easily if what we see exists or not, thus eliminating 90% of the risk of over-interpretation.

The risk of over-interpretation still exists but it is very limited. An incorrect assumption (e.g. over-interpretation, for example) cannot readily endure because it will clash with dozens of details that one can see in the other LAM images. 

It is the strength of this technique that it does not give only one image, as do the infrared or X-rays, but thousands of them. You have failed to differentiate my method from older ones.

In other words, Cotte's own cameras and computers tell him that there is only a 10% chance he is wrong. Obviously, I disagree entirely. In fact, I'd say there is about a 10% chance he is right.

M. Cotte also says:

I agree with you that the 4 fingers are not enough on their own to demonstrate that there was no ermine at the beginning of the picture. The hypothesis is based not only on this picture, but on many many others elements, demonstrations, etc. developed in my book. I

n fact, in your article, without knowing it, you demonstrate that I'm right about the hypothesis without the ermine. You draw attention to the discoveries of the nice interlaces revealed by the L.A.M. and you write "We can see in the image below, for example, that Leonardo made a number of changes to the dress, including in the detail on the sitter's left arm - the intricate scroll pattern appears beneath the red layer we see in the finished painting, and echoes that seen on her right arm."  These "scroll patterns" are interlaces. If you work with an expert in costume who knows precisely the fashion at this time (as I am working with Elisabetta Gnignera) you understand that the position of this interlaces involves putting her left arm in a very different position, which is totally incompatible with the presence of an ermine (or anything else) in the actual position.

This last statement, I'm afraid, makes no sense at all. The alteration to the dress in the sitter's left arm, is a cosmetic one - the 'interlaces' have been painted over. Perhaps Leonardo found them too visually distracting. This relatively minor alteration cannot then be interpreted as evidence that the arm cannot have originally held anything else, no matter what a costume historian might say.

To follow up this point, I asked M. Cotte if he had detected evidence of these 'interlaces' behind the ermine and behind the sitter's right hand. If the ermine was not originally included, and if the hand was in the lower position Cotte claims, then we should surely be able to see the 'interlaces' going all the way across the sitter's chest on the collar of her dress, and also all the way down the edge of her chest on the left hand side of the picture, as seen in the first reconstruction image above. Since M. Cotte's cameras detected evidence of the 'interlaces' underneath the (apparently quite thick) red paint on the sitter's left arm, we should expect to see them similarly revealed in other areas. But alas it appears that there is in fact no evidence of these 'interlaces'. Which seems to me pretty clear proof that the picture was not painted in the manner M. Cotte claims. 

Finally, M. Cotte adds:

As mentioned in the beginning of my book I constituted a  "Reading Committee" with 18 people, Conservators, Art Historians, Scientists, Restorers, Experts. Because doubt is the engine of all sciences. I approached this study with humility by seeking the advice and recommendations of many well informed experts. Each detail, each shape, each drawing, each pentimenti was analysed carefully by people who are highly experience in analytical techniques. Dr. Janusz Walek, the chief Conservator of the Lady with an Ermine in Krakow, who knows the painting better than anyone, totally agrees with my findings. Dr. David Bull who studied this painting in detail when it was exhibited in Washington and wrote the most serious scientific publication about it, has also agreed with the discoveries. 

I'm a little alarmed that two such influential conservators, who one would expect to know their way around a painting, really believe all this.  

* Note - not infra-red, as I mistakenly said earlier.

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