Post by vintageslrs on Jan 9, 2006 19:57:05 GMT -5
Folks
this was posted in another camera group which I visit.... I think it will be of interest to all Spotmatic/Takumar fans in our Board
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I tested my M42 lenses for radioactivity. I bought on Ebay 2
Geiger meters
one is small, like a compact camera, "Terra-P" counter. It measures
radioactivity in Microsievert
www.ecotest.ua/en/terra-p.html
and second is 2 times bigger, like a SLR, "RDX nuclear" counter. It
measures in milliroentger
www.dangerouslaboratories.org/rad.html
10 microsivert = 1 milliroentgen
The nornal level in the city is around 0.10 microsievet
the results are:
all 3 takumars I have:
Super-Takumar 55:2.0, Supermulticoted Takumar 55: 1.8 and SNC Takumar
55:2.0 are having radioactivity 3.5 microsievert. So all 3 lines
of Takumars are hot, having radioactivity level approximatly 35
times normal level.
I do not have 1.4 Takumars, but they are famously radioactive.
I do have 1/4 50mm EBC Fujinon and this lens is very hot, having
radioactivity level 12.0 microsievert - 120 times normal level. So I
suppose that Takumar 1.4 lenses are no less radioactive.
My 1.4 Fujinon EBC is also yellow, like all 1.4 Takumars, as
yellowing appoximatly correlates the level of radioactivity but 1.8
and 2.0 Takumars are not yellow, having radioactivity level only
3.5 microsievert
Of Fujinons I have 55:1/8 EBC and 100;2.8 EBC have normal level of
radioactivity around 0.10 microsievert
Chinon multi-coated 1.4 55mm is normal
Mamiya-Sekor SX lenses I have: 1.4 55mm, and 1.8 55mm are normal
Soligor 50mm 1.8 lens is normal
Yashinon- DX 50mm 1.7 and Yashinon - DS 50mm 1.9 are normal
Vivitar 50mm 1.9 and Vivitar 135mm 2.8 are normal
Sears (auto) 300mm 5.5 is normal
So, it looks like for high quality Takumar lenses and 1.4 EBC Fujinon
one have to pay with your own health
Level of lens's radioactivity drops to a zero at 1-2 meters from the lens
So, if it may be okay to keep hot lenses in the closet, or use them
ocasionally, it obviously no good idea to keep them on the body and
especially to put your own eye in a hot lens.
Do non believe? - Buy a Geiger counter and measure!
Because if you had bought your super-multicoated 50mm 1.4 Takumar 35
years ago for 500 dollars and now you are dying from tumor of the
brain or blood cancer - it is your own problem and nobody will sue
Pentax like Philip Morris.
Chuck Ibolite, M.D., by the way
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Kinda scares me....as I have a few Takumar lenses...including a F1.4 lens.....
What do you think? Reason to be concerned?
Bob
this was posted in another camera group which I visit.... I think it will be of interest to all Spotmatic/Takumar fans in our Board
-----------------------------------------------------------------------
I tested my M42 lenses for radioactivity. I bought on Ebay 2
Geiger meters
one is small, like a compact camera, "Terra-P" counter. It measures
radioactivity in Microsievert
www.ecotest.ua/en/terra-p.html
and second is 2 times bigger, like a SLR, "RDX nuclear" counter. It
measures in milliroentger
www.dangerouslaboratories.org/rad.html
10 microsivert = 1 milliroentgen
The nornal level in the city is around 0.10 microsievet
the results are:
all 3 takumars I have:
Super-Takumar 55:2.0, Supermulticoted Takumar 55: 1.8 and SNC Takumar
55:2.0 are having radioactivity 3.5 microsievert. So all 3 lines
of Takumars are hot, having radioactivity level approximatly 35
times normal level.
I do not have 1.4 Takumars, but they are famously radioactive.
I do have 1/4 50mm EBC Fujinon and this lens is very hot, having
radioactivity level 12.0 microsievert - 120 times normal level. So I
suppose that Takumar 1.4 lenses are no less radioactive.
My 1.4 Fujinon EBC is also yellow, like all 1.4 Takumars, as
yellowing appoximatly correlates the level of radioactivity but 1.8
and 2.0 Takumars are not yellow, having radioactivity level only
3.5 microsievert
Of Fujinons I have 55:1/8 EBC and 100;2.8 EBC have normal level of
radioactivity around 0.10 microsievert
Chinon multi-coated 1.4 55mm is normal
Mamiya-Sekor SX lenses I have: 1.4 55mm, and 1.8 55mm are normal
Soligor 50mm 1.8 lens is normal
Yashinon- DX 50mm 1.7 and Yashinon - DS 50mm 1.9 are normal
Vivitar 50mm 1.9 and Vivitar 135mm 2.8 are normal
Sears (auto) 300mm 5.5 is normal
So, it looks like for high quality Takumar lenses and 1.4 EBC Fujinon
one have to pay with your own health
Level of lens's radioactivity drops to a zero at 1-2 meters from the lens
So, if it may be okay to keep hot lenses in the closet, or use them
ocasionally, it obviously no good idea to keep them on the body and
especially to put your own eye in a hot lens.
Do non believe? - Buy a Geiger counter and measure!
Because if you had bought your super-multicoated 50mm 1.4 Takumar 35
years ago for 500 dollars and now you are dying from tumor of the
brain or blood cancer - it is your own problem and nobody will sue
Pentax like Philip Morris.
Chuck Ibolite, M.D., by the way
-----------------------------------------------------------------------
Kinda scares me....as I have a few Takumar lenses...including a F1.4 lens.....
What do you think? Reason to be concerned?
Bob