Henri Helis was the pupil of Victor Henry in his private class in Paris. From 1901 to around 1904 he lived in northern France and Belgium. He married in 1900 and settled in Paris, often returning to his family home in Romorantin. From 1910 to the beginning of World War I he worked in Brittany.

He used the Impressionist method of plein-air painting in front of the subject. His style was also inspired by Impressionism but with a more relaxed, divided touch and freer style. His colour range varied according to the climate of the regions visited, either bursting with sunlight or tempered by northern mists.

He began to exhibit at the Salon des Indépendants in 1897, became a committee member in 1900, and was on the committee in 1903, 1905, 1906, 1908, 1911 and 1920, but did not exhibit during those years. From 1900 he exhibited at the Salon des Artistes Français and at the Salon d'Automne from its inception in 1903. From 1913-1923 he participated in the Salon d'Hiver, of which he was a committee member, and which gave a posthumous exhibition of his work in 1945. He was also a member of groups in Nevers and Duneden in New Zealand. He painted in several regions of France, particularly Loir-et-Cher and Île-de-France, the outskirts of Paris, the banks of the Seine in Sologne, in the north and Belgium, particularly Bruges, from 1902-1906, and in southern Brittany from Lorient to Douarnenez from 1910-1914.