The project of Solargraphy was started by Finnish artist Tarja Trygg. She tried to use the film tube to make a small pinhole camera to record the sunshine track. What I photographed through Solargraphy is not only the lapse of time like memory, also the use of photos to condense the chain of time. The photographic paper is placed in the same scene for several months, recording the sun's path, and then developing these trajectories on silver salt negative photographic paper through long exposure, faithfully recording the changes of nature and the passage of time. This negative photographic paper is quite sensitive to light, and it produces a negative sensation when the sun is exposed for a long time, and the color is automatically reversed due to overexposure. It also burns due to the long-term exposure of the sun, making the sun appear strong and focused. By using different methods, the trajectory of the sun can draw different lines on the photographic paper, observing the relationship and trace between the environment and the sun's trajectory.