RE: [Rollei] Why the 6-element lens for 3.5Fs

["Kotsinadelis, Peter (Peter)" <peterk >]

I think that was the Rollei 2.8A and a Tessar, but experts here can
better explain this than I.

- -----Original Message-----
From: Nick Roberts [mailto:nickbroberts  
Sent: Wednesday, April 30, 2003 1:17 PM
To: rollei  us
Subject: Re: [Rollei] Why the 6-element lens for 3.5Fs



- --- Marc James Small <msmall  > wrote:
> Franke & Heidecke did NOT reject 50% of Zeiss
> Planars.  The rejection rate
> for both Planar and Xenotar was less than 5% and the
> lenses were returned,
> as appropriate, to Zeiss or Schneider, who destroyed
> the glass and reused
> the mounts, for the most part.
> 
> Linhoff found that they rejected around 5% of Zeiss
> lenses and 3% of
> Schneider lenses, but that was when Zeiss was
> swamped with orders and was
> winding up its LF lens operation.
> 
> Marc

I have several times heard the story that some of the
original 5 element Planars were incorrectly assembled
with an element reversed - now is that an old wives'
tale (as I'm inclined to believe) or is it true? If
so, it could explain a 50% batch rejection rate.

As an aside, has anybody ever tried the 2.8 Opton
Tessar?

As another aside, I was convinced my Planar-ed (and
unmetered) 3.5F was a 5 element lens - I had always
assumed that because it wasn't a 12/24 model it would
be too old (yes, I know about assumptions!) and only
checked the serial numbers of cameras and lens this
morning (and the lens coating colour). The interesting
point is that this 6 element lens does not outperform
my (I assume!) 5 element Xenotars - there's a touch
more contrast, and a different colour balance, but
neither newspaper nor brick wall tests can separate
resolving power, even at the edges. Whilst this is in
no way a scientific test, it does make me wonder if
there really is a performance hike with the 6 element
lens, or if indeed it was to simplify production.

As a final aside, when was the Xenotar modified?

Nick

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