Voigtländer Petzval 3B 2 inch Diameter NEED HELP

Hello guys, I just bought a Voigtländer Petzval. Maybe it´s a 3B because the glass diameter is 2 inches.

But there´s a problem... The "magnifying" rear element is missing. I don´t know how it´s called correctly.

I found a really good solution for my problem, a optics company will build a element for me, for small money, but I need to have the specs.

I know all measurements, but not the actual focal length of the element itself.

Maybe somone is out there to measure it for me.

Just take the magnifying positive lens element apart from the rear metal tube element

When you take off the back element and seperate it into two lenses, there must be an "magnifying one (the fore piece) and a bigger piece.

Then you can measure the focal length just by your window

Take a measuring ruler and focus on infinity (a house far away) with a ground glass and measure the distance between the lens element and the ground glass.

I hope someone will help me :)

maxi, you can find prescriptions here: http://www.dioptrique.info/base/m/m_voigtlaender.HTM

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Originally Posted by Dan Fromm

maxi, you can find prescriptions here: http://www.dioptrique.info/base/m/m_voigtlaender.HTM

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I´m not sure... Cannot find it there

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Originally Posted by maxi0909

I´m not sure... Cannot find it there

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What do you think the first four items in the list are?

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Originally Posted by Dan Fromm

What do you think the first four items in the list are?

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I don´t know... Maybe I´m not able to read this list. Can you tell me what you think is the right one or the focal length I´m searching?

Prescriptions are normalized to 100 mm. For other focal lengths, multiply the 100 mm specifications (radii, thicknesses, spacings) by "other focal length"/100.