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发表于 2008-8-26 22:05
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Carl Zeiss Jena & Super Takumar Radioactive lenses in Screw mount
Hi, my name is Aldo & I am dropping you a line from Switzerland...I
have been using & collecting cameras for 30 years...Some years ago I
have come across an article in a British magazine concerning optical
lenses emitting Radioactivity.....I have been surprised and quite
alarmed so I have decided to have some of the lenses tested at the
School of Physics of the University of Geneva.....When I got there
everybody was laughing but it did not last long because the Geiger
counter reacted in different ways to the following lenses:
Pentax Super Takumar 50/1.4...Various degrees of radioactive
radiation on three lenses, one of them quite strong (Alert
level)..Emissions disappeared after lenses where about 50cm away from
counter. The 2 50/1.8 Takumars tested on the contrary were not
emitting.
Carl Zeiss Jena Pancolar 50/1.8 moderate/strong emission on one of
them, fading at about 50cm (this one has a yellowish amber color when
looking through the glass). Extremely strong emission of a Pancolar
50/ 1 1.4 (Pentacon Super) second only to n Aspherical Canon 50/ 1
1.2 (not M42 mount). Other 50mm pancolars where not radiating at all..
Now this is quite a disturbing find, for it is virtually undisclosed
or unknown in the photo community. Furthermore it looks like the
radiation emitted from glass is the Gamma type, the most dangerous (
not stopped by a 3mm steel plate between lens and Geiger counter).
It looks like the radiation comes from the glass, not the coating..If
you search in the net under "Radioactive camera lenses" you will be
surprised to find quite a lot of info....
At this point I am forwarding this message to be able to get some
feedback and to warn you to some extent not to leave your equipment
under your bed or to carry cameras & lenses hanging from your
shoulder for too long...I have spent lot's of time disassembling,
cleaning and collimating a few of these lenses totally unaware of the
potential danger for many many hours holding them in my hands with my
eyes within centimeters....Also I may want to get some knowledgable
info about the effect on film....I believe it is criminal to
overlook this, believing that the photo industry probably has known
this for a long time....Phone calls to the Canon & Minolta importers
distributors where not welcome on the subject..Mails to manufacturers
were left unanswered...There are millions of such lenses out there
though most are safe....I have been checking the following:
Zeiss Jena 50/35/20/135mm only the some of the Pancolars and two
Flektogon's (P.six mount) reacted positive
1 minolta. 58/ 1 1.2 out of 2 tested.. The 58/1.4 & 1.7 OK.
Canon 58/ 1 1.2 Aspherical 1 positive. The other Non aspherical
Ok...Also a 35/2.0 canon positive..50/ 1.8, 1.4Ssc OK....
Regards Aldo Di Bernardo
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