Identifying lens characteristics using reflections

A system comprising:

• memory;
• and
• one or more processors at a device coupled to the memory, wherein the memory comprises program instructions that, when executed on the one or more processors, cause the system to perform operations comprising:
• producing a pattern of light using an arrangement of light sources;
• detecting reflections in an image obtained via an image sensor, the reflections corresponding to light from each of a plurality of the light sources reflecting from a surface of an attachable lens;
• and
• determining a focusing strength of the attachable lens based on a detected pattern of the detected reflections and a 3D spatial relationship between the image sensor and the light sources, wherein different detected reflection patterns correspond to different focusing strengths of the attachable lens.

A non-transitory computer-readable storage medium, storing program instructions executable via one or more processors to perform operations comprising:

• producing a pattern of light using an arrangement of light sources;
• detecting reflections in an image obtained via an image sensor, the reflections corresponding to light from each of a plurality of the light sources reflecting from a surface of an attachable lens;
• and
• determining a focusing strength of the attachable lens based on a detected pattern of the detected reflections and a 3D spatial relationship between the image sensor and the light sources, wherein different detected reflection patterns correspond to different focusing strengths of the attachable lens.