Abstract: Objective Photography, as an innovative method of recording Chinese gardens in the late nineteenth and early twentieth centuries, had a significant impact on the study of gardens both then and in later generations. In spite of this, garden studies and photographic studies do not overlap very much as they are two parallel disciplines. In garden studies, photographic images, like garden paintings, are generally used as image documentation for garden spaces. Rather, in the research process of photography history, the garden image is not the main research object. Because of its image art value or conservative ideological concepts, photography history has less explored its related content. The purpose of this paper is to draw comparisons between photographic representations of space and garden research texts. As an emerging image material and a way to understand and view gardens, photography has driven a shift in gardening research. The study investigates the mechanisms that lead to this influence. It explores the interaction between photography's technical characteristics and camp gardens' spatial characteristics. Methods This study uses the case study approach to take Osvald Sirén's photographic images of Chinese gardens as the object of study. Two paths are followed in the study. The first research path takes photography technology and photographic images as the starting point, and carries out photographic image shadow threshold analysis to analyse the technical points of Osvald Sirén's photography, which places extra emphasis on the quality of shadow, as well as the characteristics of the images of the gardens that are reproduced under the scenarios in which these photography techniques are applied. Furthermore, this paper examines how people's perceptions of garden space have changed as a result of these features. Another path is based on Osvald Sirén's research experience, to conduct a comparative study between photographic images and written documents on his writings and research texts on Chinese gardens, to explore the reverse shaping of garden memories and garden understandings through image technology. This paper belongs to the intersection of the history of gardens and the history of photography, and provides an in-depth analysis of the interactions between garden space and photographic technology in order to explore the internal, non-obvious connections. Results The results show that Osvald Sirén used a large-format camera, a medium-focal-length lens, and technical concepts similar to those of the Zone System to increase the density of the image's shadows, deepen the details, and compress space during photographing. His early studies in art history profoundly influenced his approach to expressing photography, and thus his perspective on interpreting gardens. The gardens photographed by Osvald Sirén often depict spatial scenes of significant depth. However, the images of the close-up, middle and distant views are all chosen to express themselves extremely clearly, and even the details of the patterns and architectural decorations in the distant views are also very clear. The shadows of the gardens under his lens have less contrast and present a softer state. His photography's pursuit of shadow and texture dilutes the common obsession with space in garden photography. Photographs give an objective and accurate perspective to garden recording, resulting in a more convincing and neutral approach. Osvald Sirén's photographs are obviously not satisfied with this. In his images, sensitivity to art mingles with the other side of the extreme pursuit of photography, and gardening expresses the art of living. The expressive power of the individual works attempts to consider the complexity of the gardens. Images are based on scattered perspectives that allow the viewer's eye to wander, emphasising the flow of light and the mood of the rocks. The localised images taken from different perspectives construct a distinct narrative language of the garden. An alternative spatial narrative language to the traditional garden narrative. With the emergence of an emerging research branch of garden space reading logic - a school of garden research based on modern iconography. Conclusion Photographic interventions in garden space study were constrained by many technical conditions. For example, the introduction and widespread use of large-format wide-angle lenses in order to depict a greater range of outdoor scenes; the aperture values that the photographer had to repeatedly adjust at different times in order to express light and shadow; the ever-shortening exposure speeds in the hope of introducing clear figures; and the exposure techniques applied in order to obtain as much clarity as possible in the sunlight (under conditions of high light ratios). All of this posed substantial challenges to early photography. Osvald Sirén clearly solved these technical problems skilfully, and this is what distinguishes his work as a valuable work of art from common garden photography. These images are not mainstream research material on photographic techniques or art, but they are certainly valuable. When comparing other garden researchers' photographs, Osvald Sirén's pictures of gardens stand out. He fully implemented the technical elements that could be applied under photography technical conditions at that time. He applied a concept very similar to the area exposure method, generating images that work with personal characteristics. These images record invaluable details of the gardens and leave extremely valuable information for Chinese gardens study. At the same time, these images of gardens with great detail content have formed a strong set of garden narratives, which in turn influence the perspective of garden research - a spatially compressed perspective with multiple details superimposed on each other, and a perspective that transforms spatial protagonists and garden narratives, which has begun to subconsciously influence the direction of garden research. The combination of this influence and western spatial research formed a very common paradigm for garden research. From another perspective, photography interventions in garden space study are constrained by a plethora of technological conditions. This process of overcoming photographic practice constraints is also the driving force behind photographic equipment iteration. Photographers' strong artistic aspirations under limited technical conditions have given garden photography, as a sub-category of photography, an exceptional artistic character. As a microcosm of the application of photography by modern overseas sinologists in their study of China, Osvald Sirén’s photographic practice provides an original and accessible perspective for the modernisation of modern studies.