The portrait from the collection of Borys Voznytskyi Lviv National Art Gallery proves that Johann Baptist von Lampi the Elder was not only a master of ceremonial portraiture. Without neglecting the external appeal, he created an intriguing and profound image of his contemporary, attempting to reproduce the psychological features of the model. According to an old inscription on the back of the canvas, the portrait depicts Joseph Liesganig (1719–1799), an outstanding Austrian astronomer, geodesist, and cartographer. He was among the pioneers in determining the size of the Earth and creating topographic maps of Galicia, as well as the author of scientific works on geodesy and geodetic devices, cartographic works, training manuals, and instructions. Between 1762 and 1770, Joseph Liesganig oversaw geodetic measurement works, which were first carried out on a large scale in the Habsburg Empire. From 1772 to 1774, he developed the first official map of the Galician lands titled "Kingdom of Galicia and Lodomeria". Attributes such as the alidade in his hands and triangulation equipment hint at his scientific field of activity. The figure of Joseph Liesganig is presented against a background of a soil clump or rock, a symbol of primordial nature. His image embodies one of the main ideas of the Age of Enlightenment: nature is a source of inspiration but must be subdued to serve people. The restrained colouring best suited the noble character. The author purposefully limited his palette to a few colours, with dark brown predominating. The blue sky and several light accents emphasize the serene image of Joseph Liesganig. The surface of the canvas is meticulously worked out as the artist applied his traditional smooth glazing. Incredibly delicate and extremely expressive are the model's face and hands. The Gallery's collection also houses a sketch for the portrait, apparently painted from life. Joseph Liesganig appears somewhat older in the sketch than in the completed work. Given the age of the portrayed man (approximately 60–65 years old), the painting should be dated to the time of Johann Baptist von Lampi the Elder's move to Vienna and regarded as an early example of the artist's portraiture heritage.