Pictures in physics education go beyond instructional functions and serve affective roles, such as attracting attention, creating fascination, and fostering engagement with the depicted content. Recognizing the importance of these affective functions highlights the need to understand and utilize aesthetic pictures in a research-based educational environment. Prior research suggests that aesthetic and affective attractiveness in pictures enhances enjoyment and engagement with the physics content. This paper offers three main contributions: Firstly, it conceptualizes and presents research-based criteria for selecting pictures perceived as aesthetically pleasing, drawing on insights from psychology and physics education research. Following these criteria, aesthetic pictures related to a given curricular content can be selected. Secondly, the paper applies these criteria to selecting pictures showing geometrical optics. It then delves into an evaluation of students' aesthetic and affective perception of the selected pictures. A validated instrument measured these responses, showing strong reliability (aesthetic perception: \alpha_C = 0.87 [0.85, 0.89]; affective perception: \alpha_C = 0.82 [0.80, 0.85]). Thirdly, it combines decorative and instructional functions in tasks and compares students' perceptions of aesthetic pictures (AP) and classroom experiment pictures (CEP) in junior high school (N = 118), using a crossover design. Results indicated significantly better aesthetic and affective evaluations for APs, with large effect sizes (AP vs. CEP, aesthetic and affective perception: d = 1.05 - 1.56 and 0.85 - 1.48, respectively). We conclude that the here developed and investigated criteria are useful for selecting aesthetic and affective pictures. This provides a basis for further leveraging their educational potential to create fascination and engagement in science education.
