Re: [Rollei] Rollei 2.8D with Problems

["Richard Knoppow" <dickburk >]

- ----- Original Message -----
From: "David Grasby" <david.grasby  >
To: <rollei  
Sent: Tuesday, April 01, 2003 2:22 PM
Subject: [Rollei] Rollei 2.8D with Problems


> Dear Fellow Rollei Users,
>
> I have a 2.8D with a 80mm f2.8 Xenotar lens. The camera is
in lovely
> condition, but the lens has 'haze' problems.
>
> I sent the camera to a techie but he only works on bodies
and couldn't cure
> the haze problem but he did loosen the front element so
that I could send it
> away for repolishing.
>
> Now, I removed the front element and the haze is not on
either the front or
> rear of the lens, but in the middle. I know precious
little about lenses,
> but I assume the front element of the Xenotar is a
doublet(?). Does anyone
> on the list have any idea about what could be causing the
haze and whether
> it is possible for it to be repolished? Is this likely to
cost more than the
> camera is worth (I paid $300AUS ($180US) for the camera)?
> Cheers,
> David.
>


   I think you mean front _cell_ not element. The front cell
has two lenses in it. The front lens is a single element the
rear lens is a cemented pair of elements. Most likely the
haze is on the glass-air surfaces inside the cell. The front
element can be removed by unscrewing the retaining ring at
the front of the cell. Schneider retaining rings have slots
for a special tool to remove them. They can also be removed
by using a friction tool made of a tube the right diameter
with a sticky rubber ring cemented to one end.
  You can make a suitable spanner from sheet metal, that's
preferable to using an adjustable spanner since it is much
less likely to slip and scratch the lens surface.
  The haze will clean off with lens cleaner or window
cleaner.
  The rear cell also has two air-spaced elements in it and
is also probably hazy.
  It is possible, but much less likely, that the haze is
from defective cement between the two elements of the rear
lens in the front. A flashlight shown into the lens will
generally help to distinguish between haze and bad cement.
  I don't know the exact source of the haze. Its very common
in older lenses. I suspect it comes from evaporation of
something from the anti-reflection paint inside the cell.
  If you decide to disassemble the cell pay attention to any
spacers which may be under the element. I don't think
Schneider uses these on Xenotars but they do on other
lenses. They must be replaced in the right place and with
the correrct orientation.

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

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