To solve the problem of low-speed flash sync Pentax soon manufactured the lens with a leaf shutter. It made fast flash syncs possible and allows for a lot of control in lighted situations. The built-in leaf shutter can be decativated and the lens became ordinary lens. There are three modes of shooting with this lens:

  • Ordinary lens. The lens can be used as a regular 90mm lens by not cocking the lens shutter. The leaf shutter speed ring and “U/S” lever may be left in any position.
  • Leaf shutter. This mode allows you to use high speed flash synch with speeds between 1/30 and 1/500. For shooting in this mode the “U/S” lever should be set to “U” for “Usual”, the camera shutter to 1/8 or lower speed while the leaf shutter to the desired speed. Next, the leaf shutter need to be cocked and X-sync cable connected to the lenses flash terminal. Then, a shot can be made. But it is very important to know that the leaf shutter should be cocked for the each shot, otherwise the cameras shutter speed will be used.
  • Multiple exposure. This mode allows to expose the same frame of film multiple times. For shooting in this mode the “U/S” lever should be set to “S” for “Special”, the camera shutter to the special “time” exposure mode and the leaf shutter to the desired speed. Next, the leaf shutter need to be cocked and cable release connected to the lenses cable release socket. Pressing the camera shutter release button locks the camera shutter open and closes the leaf shutter. Now it is possible to use the cable release on the lens to take multiple exposures without advancing the film. The lens shutter should be cocked for each shot of the multiple exposures. Turning the camera shutter speed dial back to 1/1000 or X closes camera shutter and stops multiple exposure.

Drawbacks

This lens is widely known for its softness. In fact, it is slightly noticeable even in the viewfinder in comparance to the other normal primes. Another feature may be that the leaf shutter is purely mechanical and therefore slightly overtimed in some lenses. But it depends on previously use of the leaf shutter and should not be a real problem.

Variants

There was only one version of this lens and it was replaced by the non-leaf shutter completely new 90mm f/2.8 in 1980.

Model Weight Year
Super-Multi-Coated TAKUMAR/6X7 1:2.8/90 610g 1971

Images

Left image: leaf shutter speed ring, sync and cable release sockets. Right image: U/S lever. The shutter cocking lever seen on both images.

Left image: leaf shutter speed ring, sync and cable release sockets. Right image: U/S lever. The shutter cocking lever seen on both images.

Diaphragm unit has five aperture blades

Diaphragm unit has five aperture blades

Lens data

  • Focal length: 90mm
  • 35mm equivalent: 46mm
  • Optical formula: 6 elements, 5 groups
  • Field of view: 53°
    • Horizontal: 42.5°
  • Mount: inner bayonet
  • Diaphragm: automatic
    • Aperture range: 2.8 ~ 22
    • Aperture blades: 5
  • Leaf shutter: 1/500, 1/250, 1/125, 1/60, 1/30
  • Close distance: 85cm
    • Magnification: 0.14×
    • Picture area: 500×393mm
  • Filter: 67mm – screw-in and bayonet
  • Hood: “Takumar 6X7 1:2.8 90mm” or PH-SB 67mm
  • Case: S90-100
  • Dimensions: 91.5×63mm

Wanted: lens formula image. Mail me, please, if you have it. Thank you!

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