Archived posting to the Leica Users Group, 2000/01/23
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In a message dated 2000-01-23 9:52:35 PM Eastern Standard Time,
bieleckj@freeway.net writes:
<< >> Regarding the Canon 50mm F0.95 lens:
> > I have seen shots taken with that lens..It sucked. It is also reputed
to
> > have contained a radioactive element, so don't put it under your pillow
at
> > night:)
> >
>
> Wouldn't a radioactive element in a lens cause film fog? Seems strange
that
> it should be purposely built in...
I think the original poster is talking about Thorium, which was commonly
used by many lens manufacturers in the 50's and 60's in their high speed
lenses.
>>
Canon also used Thorium in their early 35F2.0 lenses. It isn't Thorium you
have to worry about though. It's Cobalt Thorium G. According to a reputable
source:
"Cobalt thorium G has a radioactive half-life of ninety-three
years.
If you take, say, fifty H-bombs in the hundred megaton range and
jacket them with cobalt thorium G, when they are exploded they
will produce a doomsday shroud. A lethal cloud of radioactivity
which will encircle the earth for ninety-three years!"
Alex
;o)