The image is a photograph of an open book with Chinese text on it. The book appears to be a table with a list of numbers and equations written in Chinese characters. The table is divided into columns and rows, with each row representing a different type of equation. The equations are written in a neat and organized manner, with the first column representing the number of equations and the second column representing their corresponding values.

The table is titled "Focal Length" and is likely used to calculate the focal length of a particular object. The text on the right side of the image is written in both Chinese and English. The background of the page is white, and the text is black.