This lecture focuses on calculating the sensitivity of an APS camera sensor. It begins with the parameters of the sensor, including pixel size, optical power, and wavelength. The instructor presents an exercise where an APS image sensor with a pixel size of 10μm is illuminated with an optical power of 200μW/cm² at a wavelength of 600nm, and the exposure time is set to 1ms. The goal is to estimate the output signal in volts. The calculation involves determining the number of photons hitting a pixel during the exposure time and using this to find the output voltage. The instructor discusses the necessary parameters such as fill factor, quantum efficiency, and conversion factor, which are crucial for accurate calculations. The lecture concludes with a comparison of estimated values and the actual output signal, demonstrating the importance of these parameters in determining camera sensitivity. Overall, the lecture provides a comprehensive understanding of the factors influencing APS camera performance.