What is the fine-grained topic of the following text: In addition to a unique, newly developed lens construction, glass with high refractive index and low dispersion qualities were used, along with optimized placement of aspherical high-precision molded glass lenses for aberration removal to the utmost limits, even image quality and contrast from the center to the edges of the image, and high resolution. Only return the topic.
Lens construction and image quality improvement techniques