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

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

C'mon BD, at least we are on a Rollei related topic. Personally I find
this interesting and a lot more enjoyable than many of the LUG
discussions.  You know the ones you never complained about! i.e., "...my
summicron is oh so sharp..." or "...the M2 rests on a pillow next to me
each night." ;-)

Peter K

- -----Original Message-----
From: bdcolen [mailto:bdcolen  ]
Sent: Wednesday, April 30, 2003 2:35 PM
To: rollei  us
Subject: RE: [Rollei] Why the 6-element lens for 3.5Fs


And now, as the sun heads for the horizon here on the East Coast, we
leave Day Three, and head for Day Four of the Great Lens Element Count
Thread.
Zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz..........
:-)

- -----Original Message-----
From: owner-rollei  us
[mailto:owner-rollei   On Behalf Of Kotsinadelis,
Peter (Peter)
Sent: Wednesday, April 30, 2003 4:51 PM
To: rollei  us
Subject: RE: [Rollei] Why the 6-element lens for 3.5Fs




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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