Thorium glass

[Imagedowser]

What is the last S/N for a Collaps.50mm Summicron with Thorium glass? I remember seeing it in discussion some years back on RFF but can't seem to locate it now…. Thanks, Imagedowser

 

[ferider]

104x and earlier are hot.

Roland.

 

[BLKRCAT]

Interesting, were any of the rigid summicrons made with thorium glass?

 

[ferider]

Interesting, were any of the rigid summicrons made with thorium glass?

I thought the rigid / DR started at 140x ? I have a very early rigid - glass is color-less.

 

[BLKRCAT]

Thats interesting. I'll have to check mine when I get home. I'm a HUGE fan of my Rigid Summicron.

I had the front element repolished and recoated by focal point lens last year and I've been having a great time ever since.

finding out if it has hot glass would just be another neat little detail about this otherwise wonderful lens.

 

[joeswe]

Interesting, were any of the rigid summicrons made with thorium glass?

The answer is NO. Thorium glass was only used in some early batches of the collapsible Summicron. None was ever used for the rigid or DR Summicrons.