[rollei_list] Re: Whiteface T with Xenar question
- From: Carlos Manuel Freaza <cmfreaza@xxxxxxxxxxxx>
- To: rollei_list@xxxxxxxxxxxxx
- Date: Thu, 19 Mar 2009 04:21:26 -0700 (PDT)
Hi Sanders:
I copied below two messages Claus Prochnow sent me in 2006 about
the Rollei TLR lense, as Marc wrote, tolerance limits don'mean some lenses can
be better than the tolerance, I guess if Schneider copied the Tessar designing
the Xenar, they also were copying the Tessar improvements they found were true
improvements (the Xenar in my 'cord IV is a terrific lens) :
"Dear Carlos.
Yes it is a classical discussion for the Rollei users: Planar or Xenotar
lenses for the TLR.
The technical specifications in quality control was the same for the Xenotar
and Planar. Monday lenses may be on lower limit than on other days. Zeiss
and Schneider of course use fully the tolerances. Therefore you find people
those of the one or the other lense prefer.
Rollei himself also has bought the Schneider lenses cheaper.
Kind regards from the oldest camera town
Claus"
"Dear Carlos.
I have been 36 years a designer and after that head of mechanic development.
I have no papers and I have hat nothing to do with manufacturing and
control. Don´t ask me.
Of course the high-quality lenses were subjected to a more exact
examination. After completion of the camera, e.g. Rolleiflex 2.8 F, was
exposed a film and the film measured. The lensees were checked at the
so-called "K 6" device manufaktured by Zeiss, also Schneider lenses!!!
The cheaper objectives were checked sample goodly.
Thats I can say.
Regards
Claus"
Carlos
--- El jue 19-mar-09, Sanders McNew <sanders@xxxxxxxxx> escribió:
> Carlos and Richard, thanks for your replies. Carlos, are
> you
> certain about your statement that the Tessar and the Xenar
> must be identical because F+H's requirements were the
> same? In this instance I'm not so sure of that.
>
> My understanding is that Zeiss reformulated the Tessar for
> the T by adding lanthanum to the glass and flattening the
> lens a bit, thereby (I am told) improving the lens's
> performance.
> I have no direct experience with the T's Tessar to
> verify this
> claim. However, I have seen lens tests online that show
> the
> T's Tessar performing up to Planar standards, far above
> what might be expected of an earlier Tessar, or a Xenar:
>
> http://photo.net/medium-format-photography-forum/0003e1
>
> John Lehman's l/mm test produced surprising results and
> I
> am wondering what others on the list might have to say
> about
> them.
>
> In any event, it appears the T's Tessar was
> meaningfully
> improved over earlier versions. Does anyone know whether
> Schneider had made similar improvements to their Xenars
> by 1975? I am guessing not but that is only a guess.
> Would
> the Xenars by 1975 have different lens coatings vis-a-vis
> their 1950s siblings?
>
> Sanders
>
>
>
> From: CarlosMFreaza <cmfreaza@xxxxxxxxx>
> To: rollei_list@xxxxxxxxxxxxx
> Date: Wed, 18 Mar 2009 19:35:00 -0300
> Hi Richard:
> The Rolleiflex T with Xenar lens is
> referred by
> Prochnow in the Rollei Report 2 _second and reviewed 2001
> edition_ ,
> it's the Prochnow Register 185/2, PR 185/2. The T with
> Xenar 3.5/75
> lens was manufactured from the beginning of 1973 to August
> 1976, 3000
> units from serial numbers T2.310.000 to T2.320.449.
> Rollei specs for Xenar and Tessar lens were identical and
> then the T
> Xenar is at least as good as the T Tessar in theory.-
>
> Carlos
>
> 2009/2/18 Richard Knoppow <dickburk@xxxxxxxxxxxxx>:
> >
> > ----- Original Message ----- From: sanders@xxxxxxxxx
> > To: rollei_list@xxxxxxxxxxxxx
> > Sent: Wednesday, March 18, 2009 12:06 PM
> > Subject: [rollei_list] Whiteface T with Xenar question
> >
> >
> > I just won a Whiteface T, a very late model
> > (s/n T2316742) and to my surprise it sports
> > a Xenar taking lens -- not the reformulated
> > Tessar that I had expected. Did the Xenars
> > of the 1970s make any improvements on their
> > 1950s-era forebears? Any thoughts about
> > the Xenars on late Ts would be appreciated.
> >
> > Sanders
> >
> > I've looked at _Rollei Report 2_ Claus
> Prochnow's book. According to
> > this no Rolleiflex T cameras were made with Xenar
> lenses. Prochow identifies
> > your serial number a PR 185/1, this appears to be his
> own system, he gives
> > the factory number as K-8 but that may cover a number
> of variations. The
> > serial number is in a block from T 2.199.000 to T
> 2.249.999 dated 1966 to
> > 1970 . Note that not all of these numbers were
> necessarily used so the exact
> > place in the series can not be determined from them.
> > Schneider has a complete list of all their serial
> numbers on line. It
> > takes a bit of digging to find it but its there. Check
> this against the
> > serial number of the Xenar to see if it fits the age
> of the camera. Its
> > possible it was replaced at some point, and if so, the
> finder lens should
> > also have been replaced. However, Prochnow, while
> highly reliable, is not
> > always complete and someone else on the list may have
> further information.
> > Perhaps Rollei did use some Xenars on this camera.
> >
> > --
> > Richard Knoppow
> > Los Angeles, CA, USA
> > dickburk@xxxxxxxxxxxxx
> ---
> Rollei List
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