Win a Pentax Limited Lens: Raffle Now Live!

c-meier · 04-30-2012, 06:56 PM

Originally posted by ultraviolet

Check this out then find it out from the above chart.

No idea what the equivalence is between those counts per minute and the chart, in µS, but the clicking sounds scary. Just for caution will store the soviet lenses (much more glass than that 50) a bit further from my bed from now on.

elliott · 04-30-2012, 07:18 PM

Originally posted by c-meier

No idea what the equivalence is between those counts per minute and the chart, in µS, but the clicking sounds scary. Just for caution will store the soviet lenses (much more glass than that 50) a bit further from my bed from now on.

Most soviet lenses are not radioactive, the only confirmed one I've seen is an Industar 61L/Z for SLRs and the 61L/D for rangefinders. By far the most common radioactive glass is Pentax Takumars.

stevebrot · 04-30-2012, 07:52 PM

Here is an interesting set on Flickr that includes measurements from many different lenses from various makers.

Radioactive Lenses - a set on Flickr

Of the top five, the highest radiation at 100 mm distance was from a Canon FD 55/1.2. Also in that group were lenses from Konica, Mamiya/Sekor, Fuji, and Pentax. Interestingly the ST 50/1.4 was used as the standard and the Canon was almost twice as hot!

Steve

c-meier · 05-01-2012, 01:52 AM

Originally posted by elliott

Most soviet lenses are not radioactive, the only confirmed one I've seen is an Industar 61L/Z for SLRs and the 61L/D for rangefinders. By far the most common radioactive glass is Pentax Takumars.

Oh. Ok. No idea why I was under the impression some of my lenses could be radioactive, in particular the Jupiter 37A. Now that I think of it, it isn't even the MC version.

RioRico · 05-01-2012, 07:10 AM

Yes, it is very dangerous -- if you grind it up and eat it.

Clavius · 05-01-2012, 07:17 AM

Neh, it's not dangerous. It only has advantages. Because of my healthy fluorescant glow, I can now read in the dark.

Sorry, I couldn't resist.

The radiation level of the Taks is so low, that it doesn't even show up on the generic detectors at airports and harbours.

**boriscleto** · 05-01-2012, 08:13 AM

Originally posted by RioRico

Yes, it is very dangerous -- if you grind it up and eat it.

But having ground glass in your digestive system is probably a bigger immediate danger than the radioactivity.

newarts · 05-01-2012, 09:03 AM

As I recall what little I know from USArmy health physics, eating the ground up lens wouldn't represent much hazard (it'd pass through too fast to do much radiation damage); like most alpha emitters, thorium is a hazard when inhaled deeply into the lungs. For deep penetration into the lungs, quite small particle sizes are required; like smoke or fog, - small enough to float in air - normal "ground glass" particle sizes are too big to represent much hazard.

Seriously, don't worry about thorium as part of glass.

stevebrot · 05-01-2012, 11:44 AM

Originally posted by newarts

like most alpha emitters, thorium is a hazard when inhaled deeply into the lungs.

Thorium emits both alpha and gamma. The link I cited above measured gamma...

As noted in many places, the radiation is weak enough so that fogging of the film is not an issue. That being said, there is a geniune concern where this type of glass was used in oculars for binoculars and such.

Steve

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
For Sale - Sold: K20D w/Katz Eye, SMC Takumar 135/2.5 (Ver 2), Super Takumar 105/2.8	kenafein	Sold Items	16	04-02-2012 11:41 AM
BBC: Probe finds high radiation in damaged Fukushima reactor	jolepp	General Talk	9	04-01-2012 09:25 AM
Anxiety before switching (back) to Pentax	intjonmiller	Flashes, Lighting, and Studio	29	10-23-2011 12:14 PM
Research on Electromagnetic Radiation from Digital Cameras?	conordoherty	Photographic Technique	8	06-02-2011 10:41 PM
For Sale - Sold: Takumar: Super Takumar 135mm f3.5 includes case, hood and caps	Peter Zack	Sold Items	7	05-17-2010 07:12 PM

04-30-2012, 06:56 PM	#16
c-meier Senior Member Join Date: Apr 2012 Location: Concepción, Chile Posts: 128	Originally posted by ultraviolet Check this out then find it out from the above chart. No idea what the equivalence is between those counts per minute and the chart, in µS, but the clicking sounds scary. Just for caution will store the soviet lenses (much more glass than that 50) a bit further from my bed from now on.

04-30-2012, 07:18 PM	#17
elliott Inactive Account Join Date: Dec 2008 Location: North Carolina Photos: Albums Posts: 1,720	Originally posted by c-meier No idea what the equivalence is between those counts per minute and the chart, in µS, but the clicking sounds scary. Just for caution will store the soviet lenses (much more glass than that 50) a bit further from my bed from now on. Most soviet lenses are not radioactive, the only confirmed one I've seen is an Industar 61L/Z for SLRs and the 61L/D for rangefinders. By far the most common radioactive glass is Pentax Takumars.

04-30-2012, 07:52 PM	#18
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Here is an interesting set on Flickr that includes measurements from many different lenses from various makers. Radioactive Lenses - a set on Flickr Of the top five, the highest radiation at 100 mm distance was from a Canon FD 55/1.2. Also in that group were lenses from Konica, Mamiya/Sekor, Fuji, and Pentax. Interestingly the ST 50/1.4 was used as the standard and the Canon was almost twice as hot! Steve

05-01-2012, 01:52 AM	#19
c-meier Senior Member Join Date: Apr 2012 Location: Concepción, Chile Posts: 128	Originally posted by elliott Most soviet lenses are not radioactive, the only confirmed one I've seen is an Industar 61L/Z for SLRs and the 61L/D for rangefinders. By far the most common radioactive glass is Pentax Takumars. Oh. Ok. No idea why I was under the impression some of my lenses could be radioactive, in particular the Jupiter 37A. Now that I think of it, it isn't even the MC version.

05-01-2012, 07:10 AM	#20
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	Yes, it is very dangerous -- if you grind it up and eat it.

05-01-2012, 07:17 AM	#21
Clavius Veteran Member Join Date: Feb 2011 Location: De Klundert Photos: Gallery Posts: 4,150	Neh, it's not dangerous. It only has advantages. Because of my healthy fluorescant glow, I can now read in the dark. Sorry, I couldn't resist. The radiation level of the Taks is so low, that it doesn't even show up on the generic detectors at airports and harbours.

05-01-2012, 08:13 AM	#22
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,477	Originally posted by RioRico Yes, it is very dangerous -- if you grind it up and eat it. But having ground glass in your digestive system is probably a bigger immediate danger than the radioactivity.

05-01-2012, 09:03 AM	#23
newarts Inactive Account Join Date: Dec 2008 Location: Ames, Iowa, USA Photos: Albums Posts: 2,965	As I recall what little I know from USArmy health physics, eating the ground up lens wouldn't represent much hazard (it'd pass through too fast to do much radiation damage); like most alpha emitters, thorium is a hazard when inhaled deeply into the lungs. For deep penetration into the lungs, quite small particle sizes are required; like smoke or fog, - small enough to float in air - normal "ground glass" particle sizes are too big to represent much hazard. Seriously, don't worry about thorium as part of glass.

05-01-2012, 11:44 AM	#24
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by newarts like most alpha emitters, thorium is a hazard when inhaled deeply into the lungs. Thorium emits both alpha and gamma. The link I cited above measured gamma... As noted in many places, the radiation is weak enough so that fogging of the film is not an issue. That being said, there is a geniune concern where this type of glass was used in oculars for binoculars and such. Steve

Takumar Radiation Anxiety

Win a Pentax Limited Lens: Raffle Now Live!