[rollei_list] Re: 2.8 80mm Opton-Tessar
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <rollei_list@xxxxxxxxxxxxx>
- Date: Thu, 16 Nov 2006 03:59:45 -0800
----- Original Message -----
From: "Carlos Manuel Freaza" <cmfreaza@xxxxxxxxxxxx>
To: <rollei_list@xxxxxxxxxxxxx>
Sent: Thursday, November 16, 2006 3:15 AM
Subject: [rollei_list] Re: 2.8 80mm Opton-Tessar
Richard, the Tessar for the Baby was a 2.8/60 and for
the 4x4 format, I mentioned this lens in one of my
posts, I guess that the prescriptions are different.
It would be interesting to know why the baby 2.8/60
was not manufactured after the war, only the 3.5/60
version, if the lens was so good it would be better to
choose the 2.8/60 and not the 3.5/60.-
All the best
Carlos
By the same token we don't really know what the
prescriptions are for any of the Rollei Tessars. I have
patents that I _think_ are the f/2.8 Biometar, Planar, and
Xenotar but I am only guessing given the dates and lack of
patent references to similar designs. Zeiss has a great many
Tessar designs, evidently they kept working on it. Which, if
any, of these designs ever reached production I have no
idea.
While its certainly possible the f/2.8, 60mm lens left
something to be desired its also possible to think of
alternative reasons for dropping it. Cost may have been a
consideration, or the shutter (larger one needed). In any
case f/3.5 Tessars tend to be better than f/2.8 ones and
those around f/10 even better. Other designs offer better
performance at large apertures, so we have five and six
element lenses on Rollei TLRs and even more elaborate lenses
on other cameras.
I suppose there must have been business records at Rollei
which would give definite answers to some of the questions
we are asking but its quite possible they no longer exist. I
expect some of the records to have been destroyed during the
war and perhaps others after the war on the basis that they
were expensive to keep and of no business use. The later has
become typical for modern businesses, which, for the most
part, have no sense of or interest in their history.
It is possible to measure the performance of actual
lenses using various optical measurement techniques. Some
are fairly simple requiring no more than a decent optical
bench, others require special, computer controlled,
instruments. Such measuements on a reasonably sampling of
lenses could decide such perenial questions as whether the
Planar or Xenotar is better, if the Xenar is the equal or
even the superior of the Tessar. Do Tessars in Rollei
cameras of varous ages all come from the same design or is
there more than one design represented, what was wrong with
the Jena f/2.8 Tessars (assuming some can be found) and etc,
etc,. This would be a major project since one would have to
assemble the samples and arrange for properly controlled
measurements to be made somewhere where the validity of the
measurements would be beyond question. When I win the
lottery and become disgustingly rich I may consider such a
project, but, as long as I must be careful of grocery bills
it will have to wait until some other angel comes along. The
only comfort I can think of is that its very doubtful if
anyone will be interested in tracking the history of the
digital cameras of our day in seventy or eighty years.
Heigh-ho, its time to try to sleep.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
---
Rollei List
- Post to rollei_list@xxxxxxxxxxxxx
- Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe'
in the subject field OR by logging into www.freelists.org
- Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with
'unsubscribe' in the subject field OR by logging into www.freelists.org
- Online, searchable archives are available at
//www.freelists.org/archives/rollei_list
Other related posts:
