Thorium Glass in the 35/1.4 Nikkor??

mynikonf2

mynikonf2

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Does the 35mm 1.4 Nikkor contain Thorium glass elements? I understood it to be that the lens starting with serial number 350001 & proceeding through lens # 376927 did contain Thorium glass. That would mean that this glass was used all through the 9 aperture blade “N” series, continued through the 7 blade “NC” series and ended with the beginning of the “K” series. Again, can anyone confirm this?

...this thread is starting behave just like my lens. :rolleyes:
 
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I cannot confirm this: I have a Non-AI, all-metal 28/2 that shared much of the design with the 35/1.4. I'll take a look, but it does not seem to have any of the yellowing of my 50/1.4 Tak.
 
My 28/2 Nikkor-NC does not show any of the yellowing associated with Thorium. I've never seen or heard of anyone complaining about yellowing in a Nikkor F-Mount lens, aside from Canadian Balsam giving a slight yellow-cast.
 
Interesting question for the folks over at the Nikon Historical Society perhaps.

Where is Fred when you need him?

B2 (;->
 
My 35/1.4 is quite yellow. It's not really usable for slide film but on B&W and digital it works fine. I've thought about treating with UV to clear the yellowing. I'm pretty sure it's in the serial block mentioned above.
 
Hi Kiu,

given Jon's recent tests and both his and my vintage 35/1.8 having amber glass, I am suspecting the 35/1.8 to be radioactive (Lanthanum + Thorium based), too.

What do you think ?

Roland.
 
It sure is radioactive. If memory serves me right, while visiting, Brian actually had a guage(being the MAD scientist that he is) that showed us a little radio-activity. Not enough to cause harm though.

Or was that a thread here?

Help me Brian...

Kiu
 
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I have measured a lens with a Geiger Counter before- but it was a BIG lens on a 35mm camera with a 1.6 million frame per second motor drive. Helium Turbine.
 
I have owned and used a Nikkor-N 35mm f1.4 for years... and it definitely develops a yellow cast which is easily cured by a few days in the direct sun. Whether this is the balsam yellowing or dirty radioactive glass, I am not sure. I have to bleach mine about 5 years or so. Since I shoot mostly B&W it does not effect the negatives too much. I usually notice first through the viewfinder, when I change lenses. It also effects exposure, about 1/2 stop at it worst. My 35/1.4 has just spent its third full day on the veranda and is almost clear again. Another few days and it will be good for another five years or so. The 35/1.4 also needs to have an overhaul, focusing is getting loose and rattly again.
 
awilder said:
Try this link: http://photo.net/nikon-camera-forum/0054IM
It should answer your question on the 35/1.4 Nikkor regarding thorium content.
Click to expand...

Thanks awilder, this is exactly what I was looking for. I had suspected this for some time now but could not find a source to back up my suspicions.
...and thanks to everyone else for pitching in before my original post became to yellow to read.
 
Canon's remarkably sharp 1st version of the 35/2 FD (the one with the concave front element) also contained radioactive thorium glass.
 
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