[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Rollei] Search for highest 5 element Planar -- how about Tessar



- ----- Original Message ----- 
From: "Richard Knoppow" <dickburk  >
To: <rollei  
Sent: Wednesday, April 30, 2003 6:09 PM
Subject: Re: [Rollei] Search for highest 5 element Planar -- 
how about Tessar


>
> ----- Original Message ----- 
> From: "Fox, Robert" <RFox  >
> To: <rollei  
> Sent: Wednesday, April 30, 2003 11:01 AM
> Subject: RE: [Rollei] Search for highest 5 element
Planar -- 
> how about Tessar
>
>
> > Hey,
> >
> > I've been deleting all the posts on the Planar debate
> since I don't own
> > a Planar, but how about a *quick* explanation of Tessar
> and Xenar
> > history for those of us who know next to nothing about
> Zeiss or lenses
> > but are curious nonetheless?
> >
> > TIA,
> > R.J.
> >
  Some errors were pointed out to me in a private e-mail.
  The Tessar of the original Rudolph patent is a f/5.5 lens
but was commercially made as an f/6.3 lens. The patent is
USP 721,240
  The speed was increased to f/4.5, then f/3.5, then f/2.8,
mainly by Ernst Wandersleb and Willie Merte, of Zeiss. Allen
Greenleaf shows a Tessar of f/6.3 speed without a patent
number but a referal to Z.Instumentenkunde Vol.7, 79 (1907)
giving the prescription.
  The precriptions and computer analysed performance of a
large number of Tessar, Heliar and related lenses are shown
in: _Modern Lens Design: A Resource Manual_ , Warren J.
Smith, New York, 1992, The McGraw-Hill Book Company ISBN
0-07-059178-4
  An analysis of the Rudolph design refered to by Greenleaf
is shown on p.198
_Photographic Optics_ Allen R. Greenleaf, New York, 1950,
The Macmillan Company
_A History of the Photographic Lens_ Rudolf Kingslake, San
Diego, 1989, The Academic Press ISBN 0-12-408640-3


- ---
Richard Knoppow
Los Angeles, CA, USA
dickburk  

------------------------------

End of Rollei Users list digest V12 #62
***************************************