Three people on a river on a tranquil summer’s day. In the foreground, a man sits languidly in a long, skinny scull. His oars are at rest and so is he. It seems he is lost in dreamy contemplation, staring straight ahead, but it is equally likely he is looking out of the corner of his eye at two young women who are gliding in the opposite direction in a rowing boat. One is in blue and doing all the work, the other is relaxing under a parasol that has absorbed so much sun it appears to be glowing. The water is a glazed grey and blurrily reflects the figures on the river and the foliage in the background. Taking in the whole scene, our eye zigzags along its graceful horizontal lines – the boats, the gentle ripples, the riverbank – and then up the side of an ancient stone arch bridge on the right to a couple of spectators gazing down on the serene view below.

When The Bridge at Grez was exhibited in London in 1890, it was praised as a ‘noticeably fine production’, despite its ‘French manner’. It is a captivating work of impressionism, one that was painted outdoors and on the spot to evoke the shifting effects of light and air. It depicts an idyllic spot in a picture-postcard French village – Grez-sur-Loing, near Fontainebleau. But while the painting’s setting and ‘manner’ were French, its creator wasn’t. John Lavery was from Belfast, but he travelled far and wide and always with his painting kit. Over the course of a career that spanned six decades, he made a name for himself as a versatile painter whose output was both considerable and richly varied.

The Bridge at Grez is just one of many of Lavery’s masterpieces on display at an enthralling new exhibition. An Irish Impressionist: Lavery on Location celebrates the artist’s life and work in the context of the places he visited and was inspired to capture on canvas.

Lavery (1856-1941) had a hardscrabble start in life. Orphaned at the age of three, he spent his early years on his uncle’s farm at Moira, County Down, and then, when he was ten, was sent to Scotland, to a distant relative in Saltcoats, Ayrshire. Five years later he ran away to Glasgow, where he attended early morning lessons at the Haldane Academy Trust. He continued his training at the Académie Julian in Paris, but after a couple of terms there he realised that working outside and embracing modern rural naturalism held more appeal than being cooped up in a smoky, crowded atelier regurgitating biblical and historical subject matter. In 1883 he left to join the international colony of artists that had formed in Grez-sur-Loing, a place made famous by Robert Louis Stevenson. At Grez, the writer said, there was an ‘incommunicable thrill’ in simple things.

Some of the work Lavery produced there is on show in the first of seven themed rooms. On the Loing, an Afternoon Chat (1884) presents a washerman and young girl under a cherry tree conversing with a man in a boat. Lavery varies his technique to create depth: thick impasto for the clumps of weeds and wildflower in the foreground, precise brushstrokes for the figures, and the thinnest streaks of paint for the sheen of the river.

The same washerwoman appears with a colleague in On the Bridge at Grez (1884). Both women are observing the activity on the river; standing apart, lounging against the bridge and looking them over is a painter – fellow Irish artist Frank O’Meara, a long-term resident of Grez, whose work Lavery admired. The distance between the figures may reflect the relationship between the artists and villagers. Lavery has applied soft tones and faint lines, particularly at the point where the ramparts of the bridge melt smoothly into the cobbled surface. Despite being the painting’s focal point, O’Meara has an inscrutable facial expression: is he attracted to the women, casually interested in them or sizing them up as a possible future subject?

After refining his craft, Lavery returned to Scotland and in 1885 became a key player in the Glasgow Boys, a group of artists that depicted aspects of everyday life. Among the work in the room devoted to this stage of Lavery’s career are paintings of families playing the newly fashionable games of tennis and croquet. Equally impressive is the series of oil sketches chronicling highlights from the Glasgow International Exhibition of 1888. This grand event saw the ever-enterprising Lavery become something of a roving artist-reporter who could set up his easel and spontaneously record interesting, colourful scenes, from bustling crowds around a pavilion to stalls and kiosks brimming with exotic wares.

Other rooms are dedicated to the journeys abroad Lavery made from the 1890s on. People play a part in these pictures, but so, too, does weather and nature. The Pergola (1906) provides a glimpse of the villa Lavery bought in Tangier and used as a winter retreat for 20 years. Sunlight filters through an overhead trellis and dapples the furniture and figures on a veranda. The Bathing Hour, the Lido, Venice (1912) is a beachscape studded with women in regulation white gowns on chairs and more indistinct individuals cooling off in sparkling water. Lavery’s long, fluid strokes neatly establish the demarcations of sand, sea and sky. Spring in a Riviera Garden (1921), composed on one of his many summer painting expeditions to France, shows a group chatting in the shade and almost engulfed by a canopy of vibrant cherry blossom.

The Great War put a stop to Lavery’s travels to North Africa and Continental Europe. One of the main attractions of the exhibition is the room containing work he produced following his appointment as an Official War Artist. The role exposed him to naval dockyards, munitions factories, Royal Flying Corps bases and airship patrols over the North Sea. Two dramatic paintings from 1917 document action and emergency measures closer to home: in Daylight Raid he takes us into his London residence and presents the view from his immense studio window of Gotha aircraft gathering in the morning sky; in A Coast Defence he creates a shock-and-awe image of searchlights strafing a vast night sky.

Although Lavery didn’t experience the horrors of the Western Front, he was still able to witness the calamitous effects of the war. In Wounded, London Hospital (1915), one of the standout paintings in the exhibition and the largest and most commanding in this room, a nurse attends a kilt-clad soldier in a ward full of casualties. In The Cemetery, Étaples, painted four years later, we get a beach scene markedly different from the kind Lavery used to produce: instead of sunbathers and strollers dotting the sand, we find row upon row of wooden crosses. It is doubtful that Lavery found this scene moving: ‘I felt nothing of the stark reality [of war]’, he once remarked. ‘I saw only new beauties of colour and design.’

Lavery on Location will lead many to expect a show made up almost entirely of landscapes. This would have been refreshing, for Lavery is best known for his portraits. However, the exhibition features an array of portraits of illustrious figures. Curiously, none of these works date from the years following Lavery’s knighthood in 1918, when he became a notable member of the establishment and enjoyed travelling to fashionable resorts and hobnobbing with high society. Two full-length portraits, which predate this period, are of his favourite sitter, his second wife. In both paintings Hazel Lavery exudes confidence and elegance, her lavish costumes – a gold skirt and shawl in one, a rose evening cloak in the other – all the more striking for being set against a shadowy backdrop.

Throughout the exhibition, the range of subjects astounds. We visit Mediterranean coastlines, Scottish lochs, Irish countryside, St Mark’s Square and the summit of the Jungfrau. We view scenes in summer and winter, at dusk and at dawn. We encounter waiters and maids, lords and ladies, snake charmers and bullfighters, outsider artists and local peasants, plus Churchill painting on the Riviera. And we look in on horse shows, regattas, casinos and tea parties.

There are over 90 works to admire. With the portraits, what we see is what we get. The rest, from the quick impressionistic sketches to the more detailed plein-air landscapes, reveal themselves in more subtle ways. None of them tell stories – Lavery was more interested in conveying a key moment or an atmospheric effect. He does so again and again here, and always with the lightest, deftest of touches.

An Irish Impressionist: Lavery on Location is at the Royal Scottish Academy in Edinburgh until 27 October.