Lead And Arsenic Is A Good Thing!! (1 Viewer)

[Kevin Purcell]

Rick,

Apparently CDGM is now the world's largest supplier of optical glass. According to Roland Christen CDGM's H-FK61(equivalent to Ohara FPL-51) is quite cheap, not much more expensive than ordinary crown glass. I imagine that's the stuff used in the Chinese ED binoculars.

And they don't make an non-ecofriendly (eco-hostile?) version of this glass (at least that they deliver as strip glass).

http://www.cdgmglass.com/stripglass.html

Their front page shows logos of their customers (Leica, Nikon, Olympus, Fujinon, Canon, Agfa, ...).

http://www.cdgmglass.com/index.html

Their technical site is here

http://www.cdgmgd.com/product.asp?yuyan=en

 

[casscade]

This is a very old thread I know, but for the sake of starting a new one I’m still curious why we have no concrete evidence on some of the old Alphas of the 90’s and up. I’ve read Leica BA’s , Zeiss Night Owls and Classics,, and the original Nikon HG’s in 8 and 10x42 all had leaded glass, then it’s been posted several times none have had it, especially the Leica BA trinovid Ultras and the Nikon lx/HG’s. My question is, is there any possibly way to tell if you actually have lead in the glass vs the lead free eco glass being used today.

 

[Maljunulo]

This is a very old thread I know, but for the sake of starting a new one I’m still curious why we have no concrete evidence on some of the old Alphas of the 90’s and up. I’ve read Leica BA’s , Zeiss Night Owls and Classics,, and the original Nikon HG’s in 8 and 10x42 all had leaded glass, then it’s been posted several times none have had it, especially the Leica BA trinovid Ultras and the Nikon lx/HG’s. My question is, is there any possibly way to tell if you actually have lead in the glass vs the lead free eco glass being used today.

I really don't mean to be a pain here, but I'm having trouble understanding why we care at this point.

 

[casscade]

For collecting basically, for me anyway, If they all had eco glass anyway then as you say who cares. Again mainly for collecting in my case, but for some the new binoculars don’t offer enough improvement over glass 20 plus years ago, especially for the inflated prices. I get the diminishing return thing as well.

I’ve been comparing a 25 year old Leica to a 2019 el sv and the improvements are minimal at best. Slight fov increase and ergos, glass may be better, may not be, depends on who you ask.

 

[Maljunulo]

For collecting basically, for me anyway, If they all had eco glass anyway then as you say who cares. Again mainly for collecting in my case, but for some the new binoculars don’t offer enough improvement over glass 20 plus years ago, especially for the inflated prices. I get the diminishing return thing as well.

I’ve been comparing a 25 year old Leica to a 2019 el sv and the improvements are minimal at best. Slight fov increase and ergos, glass may be better, may not be, depends on who you ask.

Interesting.

I never thought about that aspect of it.

Thanks.

 

[Pinewood]

Hello,

My recollection is that by 2004, when I bought a Zeiss Victory 1, eco glass had become common. That puts the Leica BA and BN on the edge but the Leitz BA probably did not have eco glass. I had some leaded crystal drinking vessels and never gave them a thought.

Stay safe,
Arthur

 

[Binastro]

Leaded crystal glass with about 24% lead by weight from memory was used as it is soft and easy to cut.

It is also grey, more obvious looking side on.

For optical glass it probably had benefits as did the earlier thorium glass.
But also disadvantages..

I don't know about arsenic in glass, but it is present in old wallpaper and may have contributed to Napoleon's demise.

Then we have radium in watches, clocks and aircraft instrument displays.
This killed the young ladies in Chicago who painted the dials and hands.

I have an astro compass that had hundreds of radium beads in the night sight. It sent my monitor screaming.

The Hassleblad very wide angle camera was discontinued because of tiny amounts of lead in the solder from memory.
This I think was an unnecessary result of new rules.

Thorium glass lenses cannot be worked on nowadays. I.e. not ground any more.
I don't know about lead glass lenses and binoculars.

I have an old Broadhurst Clarkson large magnifying glass and that looks green side on.

Modern high end glass also has disadvantages.lt tarnishes as soon as it is made and has to be coated immediately. The edges also have to be painted, preferably in two coats selected for each glass type.

Regards,
B.

 

[Maljunulo]

This killed the young ladies in Chicago who painted the dials and hands.

Mostly because they wet the tip of their brushes by sticking the brush in their mouth to bring it to a fine point.

 

[Patudo]

A most amusing read. I wonder whether the original poster is still using his "pride and joy" pre 2002 Nikon 8x42 HG?

 

[Binastro]

It seems that it was the Summar for Leica introduced about 1934 that had leaded glass in an external element.
When new this lens had very fine central resolution because of the lead glass.
But, as with lead crystal glass, the glass was soft and easily scratched.
So after not very long the image was affected.

The same seems to have resulted with the Xenar, presumably by Schneider.

The green glass with the Broadhurst Clarkson large magnifier is probably due to iron in the glass.

One of the main advantages of modern lens design is the very powerful computing power available, as well as the advances in glass chemistry and coating techniques.

Cerium was I think used to give whiter glass.

Presumably leaded glass for binoculars was used in internal elements, as this type of glass is easily scratched.

Thorium glass in a few astro eyepieces can be found in front, rear or internal elements.
The same is true with thorium glass in lenses.

Regards,
B.

 

[SUPPRESSOR]

A most amusing read. I wonder whether the original poster is still using his "pride and joy" pre 2002 Nikon 8x42 HG?

Still in the family and still giving great views.

 

[casscade]

I’ll add the original Nikon HG stands up to today’s alphas and betters some as far as resolution. The 8 and 10x42 has some incredible views regardless of what decade it is,other than the smaller than current apparent fov they’re excellent.

 

[dries1]

I have both the 8 and 10X42, and agree with the optics, but they are heavy. The LX L and later Premier models discarded some of the weight in the casing material to make them competitive to others, re - weight. To me still an enjoyable glass.

 

[casscade]

Could only imagine those binoculars updated with a modern 65-70 apparent fov.