Pentax DFA 70-300mm f/4.5-5.6 SR lens patent

Ricoh has a patent (P2018-224783) for what appears to be a new Pentax DFA 70-300mm f/4.5-5.6 SR or similar:

  • Focal length: 72.2 135.0 193.2
  • F value: 4.43 4.88 53.4
  • Back focus: 38.3185 49.5751 57.6036
  • Seven different lens designs are described in the patent with apertures ranging between:
    • f/4.43 and f/4.63 at the shortest focal distance
    • f/4.88 and f/5.19 at the focal distance of 135mm
    • f/5.34 and f/5.74 at the longest focal distance

Via Pentaxforums, Digicame-info

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