An analytical approach to the quality of natural light within the vault of Madreseh Sepahsalar Mosque (Shahid Motahari).

Natural light as the only source of light in historical buildings can play a crucial role in changing interior spaces. Iranian architects artistically directed the light beams to the interior and partitioned integrated spaces without using separation elements or materials. Main question of this research is “how does sunlight  create spaces within southern vault of the mosque by establishing a combination of light, shade and darkness, and what is the role of light is in spiritualization of the main altar of the mosque? For this purpose, the light intensity was measured in the southern shabestan and altar using devices and a 12-month light travel simulation was performed by Dialux and the data were analyzed.The results suggest that luminance is the highest at noon prayer time every day in a year, promoting the spiritual space of the altar. On one hand, intensity of the light with aforementioned functions within the vault instead of using separation walls resulted in functional separation of the spaces. The difference of this research with previous ones is the use of photometric devices and quantitative analysis of the light in order to reach an analytical approach and to explain the importance of divine light in mosques.