Which Nikkor 35/1.4 uses a thorium element?

[Akira]

According to our serial nuimber guru Roland's website, only the prototype Nikkor 34/1.4 is indicated as the one with thorium glass element.  However, a well-known Nikon secondhand shop in Tokyo says that the one with the ser. #368494 has its element yellowed.  The attached image is of the one in question.  It has the earliest metal hil-and-dale focusing ring.

The seller doesn't clearly say that it has a thorium element.  But I wonder if it actually has one.

Any ideas?

[pluton]

My impression from the various 'radioactive lenses' articles and discussions on the net in the past few years is that the very first model of the 35/1.4 had a radioactive element, and that the lens was redesigned to eliminate it upon the transition to the 'K' or 'New Nikkor' rubber gripped design.  The several( 5 or 6?) 35/1.4 all-metal barrel samples I've seen had the heavy yellow color tint.
However...the early metal-bodied 28/2 Nikkor I used to own had a yellow tint compared to the later K, Ai, AiS versions- and that lens supposedly never had radioactive elements in any version.

[Akira]

Thanks, Keith, for the comment.

I also had the similar impression.

As for the yellowish tint of the lenses other than 35/1.4 in question, I've also had the older high-refractive-index glasses tended to have yellowish tint even without thorium.  I also realized that Nikkor-H C 24/2.8 I had showed the yellow tint, too.  The later versions of 24/2.8 didn't have the yellow tint.

[Dr Klaus Schmitt]

I would have called it "thoriorated", as Thorium Dioxide was added to the glass melt to achieve a higher index of refraction
https://en.wikipedia.org/wiki/Thoriated_glass

[Akira]

Klaus, thanks for the link!  In order to keep your post making sense, I keep the thread title as it is.

By the way, I also heard that that although the browned thoriorated glass will be clear again by annealing or being exposed to the (UV) light, it will then fog and become useless eventually.

[Roland Vink]

All the Nikkor-N and N.C 35/1.4 lenses (those with metal scalloped focus ring) use the Thorium glass. On my site I mention Thorium for the prototype on the assumption that the same should be repeated for the following listings. When you get to the NEW-Nikkor (K) version I state "No Thorium" to indicate when the glass material changed. The same is implied here: http://nikkor.com/story/0027/
"This lens has been used to date since its first introduction in 1971 through changes in the lens barrels and the adoption of what was then the latest super-integrated coating technologies; changes were also made to the optical system at the time when the lens barrel design was changed to the NEW-Nikkor. Though the basic lens construction remained unchanged, the glass material and the lens curvature were changed by Teruyoshi TSUNASHIMA, to improve the performance at open aperture."

Due to lack of space I don't repeat every feature for every sub-version, for example for AI kits I list the first version, implying the following version should also accept the same kit, until another kit is listed or the AI version is reached.

[Akira]

Roland, thanks for the clarification of your list.

Your way of sparing the entry spaces makes perfect sense.  But, as the prototypes are quite special, I failed to read this particular section in question as you intended.

In the One Thousand Night, the author didn't specify the use of thoriorated glass, probably because of the concerns of any radioactive materials of Japanese people...