Periscope lens module: pushing the limits of mobile telephoto photography

In the wave of smartphone photography, the periscope lens module, with its unique design, has broken the limitations of mobile telephoto photography and moved from high-end to widespread use. However the road ahead is fraught with challenges.

The periscope lens, which borrows the principle of a perope, uses mirrors and prisms to bend the light path, achieving high-magnification optical zoom in a slim body, such as the OPPO Find8 Ultra, which accommodates a five-camera system in a 9mm body, including 6x and 3x periscope telephoto lenses, greatly shooting capabilities. However, pursuing higher zoom ratios requires increasing the number of lenses and elements, which exacerbates light transmission losses and reduces image clarity and contrast; theaturization of lenses makes it extremely difficult to control aberrations and chromatic aberrations, and the edges of the image are prone to blurring and distortion high-magnification zoom, which was a prominent problem in early models, making it crucial to optimize the optical structure and balance zoom and image quality to achieve a breakthrough.

The internal space of a smartphone is compact, and the periscope lens module, especially the high-magnification version, occupies a large space, forcing manufacturers to re-arrange other components, such as designing the battery shape specially and sacrificing some capacity to adapt, affecting overall performance and battery life of the smartphone. The heat generated by the module's operation, coupled with poor heat dissipation in the confined space, can easily lead to decline in image quality and device failure, making it imperative to plan the space reasonably and solve the heat dissipation problem.

Compared traditional camera telephoto lenses, there is a gap in imaging quality for periscope lenses. With smaller lenses and limited aperture, they suffer from insufficient light intake in-light environments, leading to excessive noise, and when shooting night scenes or in low light, the dark areas lack detail and texture; in high dynamic range scenes, narrow dynamic range often results in overexposure and underexposure, and color and detail reproduction are distorted. Optical design, sensor technology, and algorithm must innovate together to improve imaging quality.

Faced with these challenges, manufacturers are actively exploring. In optical design, they are developing new lens materials and to reduce light loss and aberrations; in space layout, they are adopting compact, high-integration solutions to reduce the impact on other components; and in improving quality, they are increasing investment in sensor research and development, optimizing algorithms, and using intelligent scene recognition, real-time HDR, and other technologies to enhance image. The periscope lens module faces many challenges, but it has great potential, and with technological progress, it will bring a qualitative leap to mobile telephoto photography helping smartphones enter a comprehensive imaging era.