safe distance for radio active lenses?
- Thread starter aaaa
- Start date
Greg Smith
Veteran
Send them to my house if you don't want them closeby anymore. :happy:
Seriously, according to this article, the radiation from glass containing thorium is barely detectable from any distance more than a meter away:
http://camerapedia.wikia.com/wiki/Radioactive_lenses
Most of the lenses with radioactive elements in the glass have probably changed color by now to the point they're unusable anyway. They are all at least 40 years old, and tend to turn yellow or brownish over time.
- Greg
Seriously, according to this article, the radiation from glass containing thorium is barely detectable from any distance more than a meter away:
http://camerapedia.wikia.com/wiki/Radioactive_lenses
Most of the lenses with radioactive elements in the glass have probably changed color by now to the point they're unusable anyway. They are all at least 40 years old, and tend to turn yellow or brownish over time.
- Greg
Thanks for the link.it is well known that these lenses can be "reset" to clear glass by a simple exposure to UV light (sun or UV led light)
http://www.rangefinderforum.com/forums/showthread.php?t=101883
also make sure the yellowing is due to radioactivity. some lenses never contained Thorium glass,
but had some elements glued together with a transparent glue. This glue was turning yellow/amber too
and there is no cure for it.
On the other hand, Thorium glass was used 40 years ago to build better and cheaper lenses, so today, most of modern lenses are probably better and cheaper without the use of thorium glasses.
http://www.rangefinderforum.com/forums/showthread.php?t=101883
also make sure the yellowing is due to radioactivity. some lenses never contained Thorium glass,
but had some elements glued together with a transparent glue. This glue was turning yellow/amber too
and there is no cure for it.
On the other hand, Thorium glass was used 40 years ago to build better and cheaper lenses, so today, most of modern lenses are probably better and cheaper without the use of thorium glasses.
Last edited:
I have a super takumar, yellow glas radioactive.
Its awesome. I wish it was more yellow....
Its awesome. I wish it was more yellow....