The APO-Summicron-M 90mm f/2 ASPH. from Leica is distinguished by its apochromatic classification, serving as a rapid short telephoto lens tailored for M-mount rangefinder cameras. This lens employs a pair of anomalous partial dispersion glass elements, characteristic of apochromats, to effectively minimize color fringing and chromatic aberrations, resulting in exceptional clarity and color fidelity. Additionally, it incorporates one aspherical element and two high refractive index glass elements to address spherical aberrations and distortion, while ensuring a high level of sharpness. The manual focus mechanism allows for focusing on subjects as close as 3.3 feet, and the lens's compact design features a built-in extendable lens hood to protect the front element.

• Apochromatic design employs two anomalous partial dispersion glass elements to virtually eliminate chromatic aberrations and color fringing for improved clarity and color accuracy throughout the aperture range.
  
  
• In addition to the apochromatic designation, this lens also uses one aspherical element and two high refractive index elements to significantly reduce distortion and spherical aberrations while also increasing overall sharpness and edge-to-edge illumination.
  
  
• Bright f/2 maximum aperture benefits working in difficult lighting conditions and also affords greater control over depth of field.
  
  
• Manual focus design provides a minimum focusing distance of 3.3' with a maximum magnification ratio of 1:9.
  
  
• Built-in extendable lens hood shades and protects the front element to reduce lens flare and ghosting. Additionally, the front of the lens is threaded to accept 55mm screw-in filters.