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Oberkochen Opton Vario-So 2.8 10-100mm zoom APTERTURE?


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#1 Chris Lange

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Posted 13 February 2017 - 01:13 PM

I have acquired this lens, but the aperture seems not to work.  It stays wide open when I try to change f-stop.

 

Is it a common flaw with this lens?  Any suggestions on how to fix.

 

I've attached two images of the lens.

 

Thank you for any help...

 

Chris

 

 

Attached Images

  • vario son-1001.jpg
  • vario son-1002.jpg

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#2 Dom Jaeger

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Posted 13 February 2017 - 07:52 PM

Because those zooms were designed to be used with the early auto-focus SR system, the iris uses a spring to return it to the closed position. So mechanically, the iris ring only opens the iris. If the spring is broken or weakened, or the iris mechanism is too stiff for the spring to move it, the aperture won't close down. You (or a technician) need to open the back to assess what's wrong.


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#3 Chris Lange

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Posted 13 February 2017 - 09:01 PM

Thanks for the explanation.  I'll consider these two options.


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Metropolis Post

Aerial Filmworks

Tai Audio

Visual Products

CineLab

The Slider

rebotnix Technologies

Paralinx LLC

Media Blackout - Custom Cables and AKS

Glidecam

Rig Wheels Passport

Technodolly

Willys Widgets

Gamma Ray Digital Inc

Wooden Camera

Broadcast Solutions Inc

Abel Cine

CineTape

FJS International, LLC

New Pro Video - New and Used Equipment

Ritter Battery