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  • The Claude Glass or Lorrain Mirror is a small black mirror used as a drawing aid by artists.

  • It is for viewing sunlit scenery: artists could work with less eyestrain.

  • Named after Claude Lorrain, the 17th-century French painter once thought to have invented it (disputed). 

  • 18th-century tourists used Claude glasses when looking at scenery. Real landscapes reflected in it were judged by how much they resembled a painting by Claude Lorrain. 

  • It is optically ground to display a wider scene than a flat mirror of the same size.

MY PHOTOS WERE TAKEN IN 2001 to demonstrate what an image reflected in a Claude mirror looks like. I had noticed that online reference sites described Claude reflections as "sepia" or "neutral" or "monochrome". Presumably, the entry writers had not seen one in use.

Drawings executed with the help of a Claude glass were often monochrome but the reflections seen in a Claude are not. 


I took some photos of my Claude glass to show on my Apple Homepage website. One was edited to monochrome to resemble the erroneous notion of a Claude reflection.


LOCATION I chose Calton Hill with its grand monuments  as the sort of place that attracted early users.


PURPOSE You can see from my photos that a Claudian mirror shows full-colour scenes without dazzle, allowing such qualities as the rounded shapes of clouds to be appreciated.     


After I contacted the editor of an online reference work devoted to scientific instruments, he viewed my site and emailed me to thank me for the demonstration. He adjusted the Claude Glass entry to take account of the new information. I wish I could remember the name of his site because I don’t know if it is still online.


The Claude glass is a black, optically ground, convex mirror said to have been invented by the seventeenth-century French landscape painter, Claude Lorrain, although that is now denied by art historians who say there is no evidence for it. “Optically ground” means that if you place a Claude mirror beside a flat mirror of the same size, the Claude displays a broader field of view. I believe the glass of a real Claude mirror is dark throughout and not simply clear glass with a black backing.

FASHIONABILITY The Claude glass was made fashionable in the English-speaking world by the poet Thomas Gray and William Gilpin, the theorist of The Picturesque. Using the Claude glass, artists and travellers were able to study intensely bright, sunlit scenes at length without eye strain, clearly make out shapes and details, work out the scale of tones and use their analyses to construct drawings and paintings (and verbal descriptions); the leisured could comfortably spend time looking at views. It occurs to me that 18th-century meteorologists might have found the Claude glass helpful in their new study of clouds.


Claude glasses went out of fashion around the middle of the nineteenth century probably due to the hostility of John Ruskin who criticised them in "The Elements of Drawing" because they falsified tones; he wanted artists to work directly from nature. Around that time, photography was replacing some functions of drawing by hand and Ruskin also warned about the dangers to artists of photography: the shadows in a photo were too dark by a factor of four in his calculation. His ideas were taken up by the French Impressionists who referred to him with admiration. I had always thought that the artists who used a “Claude” were professional painters or engravers but some writers insist that they were used by amateurs only. I don't know whether Claudes have been found in the inventories of professional artists (including engravers) of the 17th, 18th and early 19th centuries.


NAMES I refer to the instrument in various ways both to match different Internet searches and from uncertainty as to how it should be referred to.


INTERPRETATIONS Today, there is a school of thought which is interpreting the "Claude" in new ways, e.g. as an 18th century kind of Instagram: "the English were once forward-looking, inventive and curious as a nation, and so they came up with their own way to grungify the views they saw on vacation, and (probably) their breakfasts" (from the Web). Instagram is a feature of modern leisure but such interpretations miss the point of what the original users were about. The modern pastime of "filtering" digital images to make them look like products of various obsolete imaging technologies was not what eighteenth-century users of these black mirrors had in mind; there was no pre-existing database of billions of images awaiting "filtering" by Photoshop; making an image was the problem and that could only be done by eye and hand and several visual aids.


OBSCURITY After the "Claude" fell out of use, people who came across them possibly thought they were spoiled, blackened mirrors or photographs on glass and threw them away. These were my first thoughts when I saw one at an uncatalogued auction preview before I realised what it was. 


PROVENANCE OF MY INSTRUMENT I was able to buy mine cheaply at the weekly "Wednesday Hall" sale devoted to dispersing household goods at the old Lyon & Turnbull auction salerooms between Thistle Street and Thistle Street Lane parallel to George Street in Central Edinburgh. No one else there seemed to know what it was and I jumped with surprise when it was "knocked down" to me at a very low price. Claudes were never common; in their heyday, they were required only by wealthy connoisseurs of landscape (who were often amateur artists) and, perhaps, by professional painters and engravers. An additional reason they might have helped professionals is that a mirror image would be reversed a second time when a print was "pulled" from a copper plate made from a drawing. That's a passing thought.


SHAPE AND SIZE I speculate that professional topographical artists might have needed the larger, almost cumbersome, rectilinear examples whereas a Lady might only have carried a pretty, little, oval one. My Claude glass has a format that puts me in mind of engravings of towns.

THE CAMERA I used was an entry-level Kodak digital camera. The capacity of such a retail consumer camera and the picture size allowed on photo-sharing sites like Homepage were both less than is common now so my pictures are quaintly "pixellated". After Homepage closed, these pictures have been hosted on other Apple picture servers but, as those have shut down too, they are now hosted here.


THE CASE is stamped underneath: "Elliott Brothers Opticians 56 Strand London” under a Royal Coat of Arms. According to, "Elliott Brothers; Opticians; 56 Strand; London" traded under this style at this address from 1853 to 1858.


SIZE: 6 1/2 x 5 1/2  x 1 inches.


APPEARANCE: Dark greenish leather, pink silk lining.


July 2015:

 I hired this Claude glass to Spun Gold TV who have made the gardening programme "Titchmarsh on Capability Brown" for Channel Four in which Alan Titchmarsh oversees and discusses the restoration and completion of the gardens at Belvoir Castle, seat of the Duchess of Rutland, following the rediscovered plans which were drawn up by "Capability" Brown in the eighteenth century. Spun Gold wrote to me that "the sequence we filmed with Alan using the Claude Glass went really well! It really brought something extra to the series, we can't thank you enough for allowing us to use it. This sequence will be shown in the final of 3 episodes".

6th Feb 2017:

I am delighted to say that I have hired this Claude to a second TV production company, Oxford Film and Television. The programme is about art and industry and has been commissioned by BBC Four.



Dr John Dee's Magical Speculum or Scrying Glass was a wonder of Elizabethan London. Two museums in London hold black mirrors said to be connected with Dr Dee. The Science Museum has a "Claude glass believed to be John Dee's scrying mirror, Europe, undated" while the British Museum holds "Dr Dee's mirror 1300/1599", made of obsidian rock and Aztec in origin. I don't know if these institutions contest each other's claims in a rivalry like that between the Louvre and the National Gallery over who owns the first or best version of "The Virgin of the Rocks" but it seems clear that the British Museum's claim is more persuasive.

The Science Museum's Dee Claude glass is an oval of black glass fitted in a wooden box covered in sharkskin and fastened with brass clasps of a conventional kind. The box is of the sort that was made for scientific instruments of all kinds and thus the Science Museum's Dee mirror has the look of something that could have been bought in a good instrument maker’s shop, that other people in London might have owned. An article resembling something that had been seen before in London was unlikely to attract the notoriety of Dr Dee's Scrying Glass and therefore I think this mirror was not Dr Dee's and that Claude glasses, however named, were unknown in London in Dee's time.

Throughout history, glass has been used to simulate objects made from various stones: carved rock crystal was imitated by colourless cut  glass; glass imitates mineral jewels in costume jewellery; opaque lithyalin glass and malachite glassware are other examples. Perhaps the portable black glass mirrors we now call Claude glasses were first made in conscious imitation of Dr Dee's famous black stone mirror. Could another origin be that the entirely oxidised, blackened silvering on old mirrors was something some imaginative people found attractive and a fashion for black mirrors arose?

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