Writer-producer-director Phil Grabsky has been set a tricky task with the latest entry in the estimable Exhibition on Screen series. Rather than focussing on a renowned artist, The Impressionists - And the Man Who Made Then centres on the shift in French painting that brought about Modern Art and transformed the way in which pictures were exhibited and sold. At the heart of this cultural revolution was Paul Durand-Ruel, a Parisian dealer who recognised the genius of painters who had been spurned by the Académie des Beaux Arts and the official salon and who risked his own financial security in order to bring their work to a wider audience.

Moviegoers, however, are much less likely to be drawn to a film about someone who sells rather than creates art and Grabsky has been rather forced into a misnomic compromise title, as the three galleries hosting the exhibition have come up with different names for their shows. The Musée du Luxembourg in Paris called it `Paul Durand-Ruel: Betting on Impressionism', while the National Gallery in London plumped for `Inventing Impressionism: How Paul Durand-Ruel Created the Modern Art Market' and the Philadelphia Museum of Art opted for `Discovering the Impressionists: Paul Durand-Ruel and the New Painting'.

Given that all three venues have devised their own layouts, it might have been interesting to explore how curators approach a shared show and vary it to suit their own preoccupations and viewing spaces. However, while Bickerstaff shows Sylvie Patry and Jennifer Thompson making hanging plans, there is no such input from the National Gallery. Consequently, the emphasis falls firmly on the unsung Durand-Ruel, although his significance is rather undersold by a film title that does scant justice to his taste and fortitude. Given that there is little discussion of the actual form and content of the paintings he handled and that there is almost no biographical information about the pioneering artists themselves, the documentary might more accurately have been called something like, The Man Who Made the Impressionists.

Following an opening montage of camera glides across some of the most famous canvases in art history, a spoken quotation from Claude Monet is delivered by Glen McCready over tinkling Debussy Prélude: `Without Durand, all of us Impressionists would have starved. We owe him everything. He was stubborn, persistent. He risked bankruptcy many times to support us. The critics dragged us through the mud, but it was much worse for him! They wrote, "These artists are mad, but the dealer who buys them is more mad than they are".'

Art historian and Sotheby's director Philip Hook concurs that Impressionism would have withered at its source without the intervention of a new kind of art dealer and Paul Durand-Ruel reveals in his voiced-over memoirs that he viewed himself as a kind of missionary or soldier who sought to ignore prevailing trends and showcase a fresh and vivid form of painting. His great-grandson, Paul-Louis Durand-Ruel, explains that he was a devout Catholic who went to mass every day and a staunch royalist at the height of the Second Empire. But, while he is right to point out the anomaly of such a traditionalist being the champion of such radically avant-garde art, this might also have been the place to note that Durand-Ruel was also widowed at the age of 40 and raised five children alone, while risking considerable sums to support such painters as Édouard Manet, Claude Monet, Camille Pissarro, Pierre-Auguste Renoir, Berthe Morisot, Alfred Sisley and Edgar Degas.

Great-great-granddaughter, Flavie Durand-Ruel, describes how his parents, Jean-Marie Durand and Marie-Ferdinande Ruel, owned a stationery and art supply shop at 103 Rue des Petits Champs, next to the Place Vendôme, which often accepted paintings in return for materials. Over an engraving of the premises, she reveals that aristocratic and bourgeois customers often rented paintings to brighten their homes or impress guests. But the majority of sales were conducted by the official salons, which appointed juries to select pictures for exhibition and, by so doing, retained a strict control over accepted subject matter and styles.

Durand-Ruel followed the salon's examples in filling his walls with frames, but Sylvie Patry, Chief Curator at the Musée d'Orsay, shows how much thought went into hanging the exhibits at the Musée du Luxembourg, so that they not only reflected the various themes and techniques of the major Impressionists, but also the spirit of Durand-Ruel, whose tenacity she so evidently admires. Anne Distel, a former curator at the Musée d'Orsay, similarly recognises his readiness to break with the conventions of either selling paintings like hats from high street stores or cramming them into exhibitions in the hope that patrons might be overwhelmed into making a purchase. As Rachel Campbell-Johnston, the chief art critic at The Times, points out, the Royal Academy still employs a jury system and she highlights the random nature of its selection processes.

Back in the 1850s, the Académie regarded itself as the defender of High Art. Yet, as Hook discloses, genre paintings like Rosa Bonheur's `Ploughing in Nevers' (1849) and Constant Troyan's `Oxen Plouging, Morning Effect' (1855) were popular for their saccharine charm until a new form of depicting nature began to emerge with canvases like Théodore Rousseau's `An Avenue in the Forest of L'Isle-Adam' (1849) and the landscapes of such Barbizon School members as Jean-François Millet (`The Gleaners', 1857, `The Angelus', 1857-59 & `Spring', 1868-73) and Charles-François Daubigny (`The Grape Harvest in Burgundy', 1863). However, while they painted `en plein air', they were not true Impressionists, as they still painted what they knew rather than the light being reflected off the view in front of them.

As Durand-Ruel confided in his memoirs (which are sonorously read by Robert Lindsay), the School of 1830 remained despised by the establishment and only a few collectors speculated on works like Jean-Baptiste Camille Corot's `Ruins of the Château de Pierrefonds' (c.1840-45) and Rousseau's `View of Mont Blanc, Seen from La Faucille' (c.1863-67). He lamented that the public shied away from such personal and original works as Eugène Delacroix's `Interior of a Dominican Convent in Madrid' (1831), which Christopher Riopelle, Curator of Post-1800 Painting at the National Gallery, commends for the audacity of its story and its style, as the scene of a figure being dragged for trial in a darkened church is atmospherically illuminated by pools of dramatic light.

Although he had developed an eye under his father's tutelage, Durand-Ruel was set to pursue a career in the army after being accepted at the Saint-Cyr Military School. However, as Paul-Louis Durand-Ruel explains, he felt unable to refuse when the ailing Jean-Marie asked him to assist in the shop and the 24 year-old realised he had made the right choice when he entered a room full of Delacroix's work at the International Exhibition in 1855 and vowed to devote himself to helping such pioneering painters find public acceptane.

Riopelle suggests that Durand-Ruel would have been drawn to the Delacroix interior because of its visual impact and the masterly freedom of its technique. He also avers that the Salon of 1859 alerted the art world to a looming crisis in French painting, as the submissions that year were particularly lacklustre and this emboldened those on the avant-garde fringe. Over shots of Manet's `Olympia' (1863), Renoir's `The Swing' (1876) and Monet's `La Gare Saint-Lazare' (1877), Hook agrees that these outsiders would have welcomed the chance to be shown at the Salon, but realised they would never be accepted and had to find alternative ways of exhibiting their work if they were to have any chance of selling it.

Hook identifies Manet as the father of Impressionism and also separates Degas from such landscape painters as Monet, Renoir, Pissarro and Sisley. The latter's `Gateway to Argenteuil' (1872) typifies the way this group painted reflected light, while Manet (`Le Déjeuner sur l'Herbe', 1863) and Degas (`Ballet Rehearsal on Stage', 1874) were never quite Impressionists at all. However, they both sought new means of representation and Campbell-Johnston notes that they were greatly aided in this regard by the invention of synthetic colour, as they could now work in the open air using tubes of paint, which would have been unthinkable in the days when they would have had to mix their own pigments. Hook explains how colour was loosened from its function in the literal depiction of nature and could become more evocative in pictures like Renoir's `Ball at the Moulin de la Galette' (1876), which anticipated the use of colour in Expressionism and Abstract Expressionism.

The Académie was certainly not ready for such a break with tradition and Campbell-Johnston decries its reverence for a calcified classicism that brooked nothing but mythological, biblical and narrative scenes. Over shots of Alexandre Cabanel's `The Birth of Venus' (1863) and Henri Fantin-Latour's `The Studio in the Batignolles' (1870), Durand-Ruel recalls in voiceover how the Salon of 1866 decided to limit artists to two works each and how he was dismayed when Manet's `The Fife Player' and `The Tragic Actor' were rejected out of hand. The following year, however, Manet followed the example of Gustave Courbet and mounted a self-financed show alongside the universal exhibition near the Pont de l'Alma. A few colleagues and some curious collectors came to study the works, but the critics and the cartoonists had a field day, as they mocked Manet's quixotic style and stance. However, as Hook rightly indicates, the French art scene had resisted change for so long that something as defiantly bold as Impressionism would have come as an enormous shock and modern art lovers accustomed to avant-gardism should not be too hard on the old guard for its reluctance to embrace the new.

But it took something as seismic as the Franco-Prussian War to shake the establishment out of its lethargy. Durand-Ruel fled to London when the conflict broke out in 1870 and started trading out of the ironically named German Gallery at 168 New Bond Street. He records in his memoirs that he tried to get himself known by mounting an exhibition without the permission of the participating artists, but felt sure that they would have approved of his actions. However, he was not entirely alone in London, as Monet and Pissarro had also gone into exile and Campbell-Johnston reflects on the fact that their style changed markedly after they saw works like Joseph Mallord William Turner's `Sea Storm - Steam-Boat Off Harbours Mouth' (1842). Indeed, she goes so far as to claim Turner as one of the fathers of Impressionism and highlights how his efforts to capture weather conditions impacted upon such Monet outings as `The Thames Below Westminster' (c.1871) and `Green Park, London' (1870-71).

As the camera lingers lovingly over details within the frames, Durand-Ruel remembers how he first met Monet and Pissarro in January 1871 and bought several paintings from each at 300 francs a time for the former and 200 for the latter. In leaner years, the pair would command as little as 100 or 50 francs per painting and Durand-Ruel admits that it was often difficult to sell their work, even when he slipped it into exhibitions of more traditional fare. Pissarro is quoted over an image of `L'Avenue, Sydenham' (1871) as being relieved to have such a generous patrons and a steady source of income, as it meant he could concentrate on his art and not where the next cheque was going to come from. Moreover, as Sylvie Patry notes, this became an important canvas, as it showed the direction in which Pissarro was staring to move.

However, as Hook declares, a certain serendipity proved crucial to the more open reception of Impressionism in the early 1870s, as the Second Empire had fallen and the leaders of the Third Republic took some time to restore order from the chaos of defeat and the Commune. It might be worth noting at this point that Durand-Ruel never allowed politics to cloud his judgement of an artist or their work, as, while he remained a monarchist, he was able to collaborate cheerfully with a Communard like Courbet, an anarchist like Pissarro and a republican like Manet.

Placed side by side in a triptych frame, Sisley's `L'Île-Saint-Denis', Pissarro's `Entrance to the Village of Voisins' (both 1872) and Monet's `Pleasure Boats' (c.1872-73) show how the Impressionist style began to take shape in the first years of peace. Patry explains the significance of the works to the exhibition, as they were the first pictures that Durand-Ruel purchased from the artists after he returned to Paris. And, as Jennifer A. Thomson, Curator of European Painting at the Philadelphia Museum of Art, reveals, Durand-Ruel was quick to snap up all available works, taking 36 from Sisley and 29 each from Renoir and Monet soon after he had re-established himself in the Third Republic. Flavie Durand-Ruel opens ledgers from the time to show how her ancestor kept his books and how rarely he managed to sell items by Monet, Millet, Renoir, Corot, Sisley and Degas Yet, as Hook insists, he was passionate about these artists and works like Manet's `Moonlight Over the Port of Boulogne' (1868) meant a great deal to him personally. In fact, as Flavie recalls, having bought it, he knocked on Manet's door and offered to buy everything else he had for sale, including `The Battle of the USS Kearsage and the CSS Alabama' (1864)

Durand-Ruel soon had around 50 Manets, among them `Music in the Tuileries Gardens' (1862), and he concedes in his memoirs that he often risked amounts he could scarcely afford on purchasing new works. He despaired that they were ignored by his regular customers and Hook points out that the ledgers reveal that Durand-Ruel came to rely on selling the Impressionists to such new clients as a pair of homeopathic doctors, an actor and a lowly paid customs official. This, of course, harks back to the golden age of Dutch painting, while also anticipating the emergence of new collectors in the 20th century. In order to entice them into buying, Durand-Ruel began producing catalogues of engravings in 1873 and Flavie leafs through the pages of some of these innovative publications.

In his memoirs, Durand-Ruel looks back with pride on the fact that his business had started to flourish by this period and that his rising credibility had also increased his credit worthiness. He concedes that he borrowed more than he could afford to secure items like Degas `The Dance Foyer of the Opera at Rue Le Peletier' (1872) and Renoir's `Danseuse' (1874), and mourns the fact that so many contemporaries thought he was mad for trying to peddle pictures they considered dull and poorly executed. His accounts of busybodies coming to his shop to poke fun and bidders at auctions turning pictures upside down to mock them betray the narrow-mindedness of the cultural élite and more might have been made here of the strain that the prolonged struggle for recognition must have had on Durand-Ruel's mindset and his domestic arrangements, as he had a young family to raise by himself. Moreover, given that he had to stop buying from the Impressionists when France lapsed into recession in the middle of the 1870s, it would be fascinating to know how this impacted upon his family life and his friendships with maligned outsiders who were forced to band together in the Society of Independent Artists in order to survive.

They exhibited works at the studio of the photographer Nadar at 35 Boulevard des Capucines (the same street where the Lumiere brothers would give the first cinema show to a paying audience in December 1895). But, whenever he could, Durand-Ruel kept buying masterpieces like Monet's `Impression, Sunrise' (1872), which was listed in his catalogue under the title, `Impression'. This was seized upon by the press, who used the term `Impressionism' in a derogatory sense when critiquing the likes of Monet's `Springtime' and `The Railway Bridge at Argenteuil' (1874) and such negative reviews brought the curious to galleries intent on ridiculing the pictures rather than looking at them and trying to understand the artists' intentions.

Following their 1874 show at Nadar's premises, the Society took up Durand-Ruel's offer to exhibit for free at his shop in 1876. However, even though it included the likes of Renoir's `Study. Torso of a Woman in Sunlight', it was savaged in an article in Le Figaro by Albert Wolff, who compared the artists to lunatics believing that stones in the road were diamonds. He delighted in the fact that the patrons derided their efforts and Flavie Durand-Ruel deeply regrets that they couldn't recognise the merits of a canvas like Berthe Morisot's `Hanging the Laundry Out to Dry' (1875), which uses deft strokes to convey both the action and the atmosphere of a scene of women hanging out washing.

In 1874, Manet exhibited `The Railway' (1872-73) at the Salon. But, while Durand-Ruel paid 5000 francs for what is now regarded as an undisputed masterpiece in 1881, he couldn't find a buyer over the next 20 years. Alarmed by his sluggish turnover, the banks began refusing him credit. Yet, he periodically saved the likes of Degas, Monet and Sisley from the bailiffs and often sold pieces for below their worth in order to acquire new items like Morisot's `Woman at Her Toilette' (c.1879-80) and Degas's `The Ballet Class' (1880-81). Their gratitude ensured their loyalty and Durand-Ruel never regretted the hardships he endured in elevating his artist friends to their rightful place.

One of the ways in which Durand-Ruel hit upon to help promote his artists was to hold monographic exhibitions. In 1883, he devoted shows to Monet, Pissarro, Sisley. Renoir and Eugène Boudin, and Thompson and Hook suggest that he was changing the rules of the game by allowing the painters to pick the works they wanted to show. Moreover, by detaching them from the Impressionist label, he was also able to market them as individuals with very different temperaments. But, as Durand-Ruel laments over shots of Monet's `Autumn Effect at Argenteuil' (1873) and `The Coal Carriers' (c.1875), Pissarro's `Farm at Montfoucault' (1874) and Renoir's `Two Sisters (On the Terrace)' (1881), sales remained sluggish and he cursed the fact that the way in which the pictures were being hung often meant that people were more content to browse than buy.

It was at this juncture, however, that he looked across the Atlantic. In 1883, Durand-Ruel took 80 paintings to Boston for an exhibition to mark the 100th anniversary of the Treaty of Paris that had ended the American Revolutionary War. Only 20% of the titles were Impressionist, but the three Manets, six Pissarros, three Monets and three Renoirs caught the public imagination and Durand-Ruel was able to cut a deal with the American Art Association in New York to import 300 pictures from the new French school, with the AAA agreeing to pay all shipping, insurance and advertising costs.

Over a shot of Paul Cézanne's `Mill on the Couleuvre near Pontoise' (c.1881), the excitement and relief surrounding this 1886 show is evident in the extract from Durand-Ruel's memoir, as is the gratitude in the snippets read from letters from Sisley and Renoir. But Hook notes that, even though he was taking a risk by introducing so many unknown talents, the post-Civil War industrial boom had generated enormous fortunes and eager collectors were excited by the prospect of buying into a new movement that reflected the energy and innovation of the united nation. In all, Durand-Ruel brought 360 `Works in Oil and Pastel by the Impressionists of Paris', including Renoir's `Dance at Bougival', Dance in the Country' and `Dance in the City' (all 1883) and he was gratified by the size of the crowds who came to the gallery and the positivity of the critics.

Hook, Thompson and Riopelle concur that America was psychologically attuned to the Impressionists, although the latter points out the role that Mary Cassatt played in convincing friends to trust Durand-Ruel's judgement. Her family owned the world's biggest corporation, the Pennsylvania Railroad, and the combination of her socio-cultural cachet and her talent as an artist (her works included `The Child's Bath', 1893) proved vital in giving the Impressionists a US entrée. Indeed, the first public institution to acquire an Impressionist picture was the Metropolitan Museum of Art in New York in 1889.

Over exquisite details from Monet's `Poplars', `Poplars on the Epte' and `Wind Effects, Sequence of Poplars' (all 1891), Durand-Ruel explains how the American success of the paintings had a knock-on effect in Paris, as collectors and critics began to reappraise the Impressionists and drew very different conclusions. Meanwhile, in Philadelphia, Thompson and assistant Ashley Boulden discuss how much they have learned about iconic images while curating their leg of the show and they are particularly pleased at being able to contrast the effects Monet was striving to achieve in six items from the 24-strong Poplar series painted near his home at Giverny.

Back in Paris, Flavie Durand-Ruel opens the last of her great-great-grandfather's ledgers and notes that, by 1921, he had handled 11,902 works of art. He concluded his memoirs by passing on the baton to the next generation to find its own iconoclasts and suggested wryly that they would not be found in the salons. Distel reminds us that he was not the first important dealer in art history, but, over Renoir's 1910 portrait, Campbell-Johnston anoints Durand-Ruel the creator of the modern art market. Riopelle confirms the magnitude of his achievement by recapping that he devoted four decades to ushering a despised aberration from the margins to the centre of artistic activity and his legacy is eloquently summed up by a closing tour of the paintings hanging in the Musée du Luxembourg, close to where this remarkable story started.

According to the company website, Durand-Ruel bought 1500 Renoirs, 1000 Monets, 800 Pissarros and 400 works by Degas, Sisley and Cassatt. This alone would make him a notable figure, as he was the first to appreciate the coherence of the Impressionist movement and his dedication to the cause enabled its fame to spread. But, while making his contribution to the transformation of French art, he also raised five children alone following the death of his 30 year-old wife, Eva Lafon, in 1871. At various times, he turned his apartment at 35 Rue de Rome into a private viewing space for the 370 paintings in his own collection, while the 1905 exhibition he staged at the Grafton Galleries in London remains the largest ever Impressionist show, with some 315 masterpieces on view. Yet, such was his modesty, that he waited until he was 69 to have his portrait painted.

Although Grabsky has produced another fascinating documentary, one consistently gets the feeling he may not have done Durand-Ruel full justice. Naturally, the visual focus has to remain on the majestic paintings produced by some of the most beloved figures in recent art history and the camera (wielded variously by David Bickerstaff, Robin Fox, Hugh Hood, Tom Quigley and Kate Reid) captures entire canvases and intimate details with unerring skill. Clive Mattock's editing achieves a similar fluidity that matches the movement of the brushwork. But, as the assembled experts are not required to analyse the pictures in much detail and absolutely no background information is provided about Manet, Monet, Pissarro, Sisley, Renoir, Morisot or Degas, one is left wondering why Durand-Ruel is allowed to retreat into the shadows.

The exhibitions in Paris, London and Philadelphia all acknowledge the centrality of Durand-Ruel to the rise of Impressionsm. But the specialists within the film concede that he was not the first and was certainly not the only dealer operating in Paris during the Impressionist decades. Might there be some merit, therefore, in exploring his rivalry with the much younger Georges Petit, who not only vouched for works by Monet, Renoir and Pissarro, but also curated retrospectives for Sisley in the 1890s and Monet's 1897 `Morning on the Seine' series?

This rivalry (and the extent to which it affected Durand-Ruel's relationships with the painters he had skirted bankruptcy to nurture), plus a greater insight into his home life would bring him more into the foreground, without taking any attention away from the pictures he strove so hard to bring to the public's attention. It says much that when Durand-Ruel was awarded the Legion of Honour two years before he died in 1922, he was recognised for his contribution to French trade rather than art. Hopefully, the exibibitions will finally see him receive the plinth he has long deserved, but the film could perhaps do a little more to demonstrate that, without Paul Durand-Ruel, the Impressionists would not be held in such universal esteem, as they would have been laughed out of existence by the sanctimonious apologists of mid-19th-century French artistic mediocrity.