I have a number of old SL66 lenses and I‘d like to keep Thorium out of my
livingroom.
So - which lenses all had Thorium glas?
Am 08.03.2020 um 20:29 schrieb Ferdi Stutterheim (Redacted sender
fwstutterheim for DMARC) <dmarc-noreply@xxxxxxxxxxxxx>:
I was wondering about the 4/55 mm Distagons of the Wide Angle Rolleiflex.
When I was visiting the Rollei factory at the time the new Rolleiflex FW was
manufactured, I was told that the original Distagon could not be made anymore
because a certain type of glass was no longer available. They had to settle
for the Schneider Super-Angulon 4/50. Could there be Thorium glass in the
Distagon? Mine has not turned yellow (yet?).
Ferdi.
----
Ferdi Stutterheim,
Drachten, Netherlands.
Op 8 mrt. 2020, om 11:06 heeft `Richard Knoppow <dickburk@xxxxxxxxxxxxx> het
volgende geschreven:
Thorium glass has properties that made it desirable for the very high
performance lenses Kodak was making for defense purposes. They probably knew
the glass would brown from the radiation but no one expected these lenses to
have a service life of more than a couple of years.
