Leica Patent For 23mm f/1.7 Lens

Leica has filed a new patent in Japan. The new patent describes Leica 23mm f/1.7 lens designed for mirrorless cameras with APS-c sized image sensors.

Leica currently has the Summicron-T 23mm f/2 ASPH model for T mount cameras.  Prime lens has a maximum aperture of f/2.

Leica T mirrorless camera ($1,850 – Amazon | B&H | Adorama) features a large 16-megapixel APS-C CMOS image sensor and a massive touchscreen display. See also the Leica T first impressions review and sample images here.

Leica 23mm f/1.7 Lens Patent

Description, self-interpretation of the patent literature

• Patent Publication No. 2015-191237
  • Published 2015.11.2
  • Filing date 2014.3.28
  • Applicant Leica camera Aktiengesellschaft
• Example
  • Focal length f = 23mm
  • Fno. Preferably F2.0
  • BF 15.7mm
  • Total length 54mm
  • Image circle 28.4mm
  • 4 times is desirable short-range total length
• Leica patent
  • Deformation retro focus (rather than a retro focus for single-lens reflex, and the sense that shortened retro focus back focus)
  • 2-group configuration of positive ShiboTadashi
  • Inner focus (part of the second group)
  • The rear lens is aspherical
  • The optical design by code

via Egami