Minolta MD 70-210mm f/4—What is this switch for?

Discussion in 'Adapted Lenses' started by WoodWorks, Apr 1, 2013.

  1. WoodWorks

    WoodWorks Super Moderator

    Dec 12, 2012
    Ashland, OR, USA
    Real Name:
    This lens has a feature whose purpose escapes me, so I'm hoping one of you old-timers can give me a clue. There's a switch that locks the aperture ring, and it only is available at f/32. I'm guessing there's some purpose to it, but for the life of me I can't imagine why anyone would want to lock the aperture at f/32. Does anyone know? I won't be able to rest until this mystery is solved. Thanks in advance!

  2. zemosabe

    zemosabe TalkEmount Rookie

    Jan 3, 2013
    Far from an old timer but this "switch" is on most of my MD lenses. The lever in the mount can't close down the aperture any more than is set on the ring. I assume the switch was designed to work with some early form of auto or speed priority mode. The Minolta X-9 I picked up in a grab bag closes the aperture down on shutter press via the lever and has an Auto mode that seems to be an early version of aperture priority.
  3. WoodWorks

    WoodWorks Super Moderator

    Dec 12, 2012
    Ashland, OR, USA
    Real Name:
    Thanks zemosabe. I've been up all night, fretting about that! :hail:
  4. Jaf-Photo

    Jaf-Photo TalkEmount Veteran

    Mar 25, 2013
    A detailed explanation of the function of the aperture lock on analogue Minolta cameras can be found on Rokkor Files - where else ;)

    Look towards the middle of the following page:
    The Rokkor Files - Minolta Lens History

    There is also a modern adapted use for the aperture lock. When you are not using the lenses, it is apparently best to store them set at the minimum aperture, to minimise the risk of oil leaking onto the aperture blades. Then the lock comes in handy to keep the blades at f/22.
  5. Purushotham Racharla

    Purushotham Racharla TalkEmount Rookie

    Mar 7, 2013
    Bangalore, India.
    Real Name:
    Purushotham Racharla
    This swithc is meant to lock the aperture at f 32/ f 16 as the case which ever is smallest aperture when you use shuuter speed priority mode. When this aperture is selected, a switch on camera is activated by a tab on aperture control ring(this is a distinctive 2nd tab added when Minolta first made MD lense. This swich provides a means of locking aperture ring so inadvertently the swich may not deactivate.

    So for the purpose of using it on NEX you may just ignore this feature. YEs you will never need to lock it.