Minolta SR mount manual focus Rokkor lenses

introduction

these manual focus lenses were designed for Minolta SR mount manual focus 35mm film SLR system using the Minolta SR bayonet lens mount
they are not compatible with Minolta autofocus 35mm film SLR system
there were three series:
- pre-MC (1958-1970):
  - these had no light meter coupling
  - early ones had no aperture communication
  - some had manual preset apertures
  - later ones had auto preset aperture diaphragms
- MC (Meter Coupled):
  - to match the very popular Minolta SR-T 101 SLR introduced in 1966
  - 1st generation (1966-72)
    - coating quality not as good as later models but did use Double Coating Achromatic
    - often used radioactive elements which cause yellow discoloration of the glass as it decays - eg. the 58mm f/1.2 and the 85mm f/1.7
  - 2nd generation (1972-76)
    - rubber focus ring instead of milled metal ring
    - black painted aperture ring instead of white metal ring
    - improved coatings
  - 3rd generation (1975-77)
    - discontinuation of the two letter code on the front of the lens which indicated number of glass elements and groups
    - further improved coatings
- MD (Minimum Diaphragm tab):
  - the addition of a new tab at the rear of the lens diaphragm ring, designed to connect with the XD series bodies minimum aperture switch, telling the camera that the aperture selected was the minimum aperture to allow shutter priority mode
  - 1st generation (1977-79)
    - excellent quality and coatings
    - many were redesigned to be smaller and lighter to compete with the recently introduced Olympus OM system
    - most have 55mm filter threads
  - 2nd generation (1979-82)
    - often the metal aperture ring was replaced with plastic
    - new lenses with slower apertures eg. 85mm f/2 instead of the older f/1.7 model
  - 3rd generation to match the Program Mode of the X-700 camera (1981-)
    - placement of the MD aperture lock
    - further reduced size and weight
    - many were of cheaper build quality to compete with increasing competition from third party lenses
    - clip on lens hoods instead of screw on
    - the last of these to be introduced was the 100-300mm f/5.6-6.7 zoom in 1996
see Rokkor files - lens history
see listing of Minolta SR lenses