[New test photos released] Leica Summicron 35/2 Eight Element copy made in China

[jonmanjiro]

If different glass is used, then the formula must be changed too. Why they choose for flint glass in the first place?

From Kevin's flickr (links below). Flint glass was originally made using lead, but lead doesn't necessarily have to be used and is mostly substituted with something more environmentally friendly these days.

https://flic.kr/p/2irx99p

https://flic.kr/p/2iru9ct

https://flic.kr/p/2iru8ra

https://flic.kr/p/2irxVz5

 

[jonmanjiro]

This is the decontamination tent over where the old glass furnace used to be at the Nikon 101 factory (the building pictured in the background). 1-2 metres of top soil, into which lots of unsavory additives (lanthanum, lead, arsenic and who knows what else) leeched during the glass manufacturing process over many years, was scraped off and taken away. The tent is there to keep all the particles in during the soil removal work. Not sure what happened to the soil after that but the site was turned into a park area and we used to do disaster drills there. The whole site including the 101 building has since been demolished and sold off. Needless to say, lens manufacturers avoid using environmentally questionable materials in their glass now.


Soil decontamination tent next to Nikon 101 building - January 22nd, 2010 by Jon, on Flickr


Nikon 101 Building by Jon, on Flickr

 

[Out to Lunch]

Ergo, why do people still buy newly made lenses with flint glass from China? It can't be their concern for the environment, nor the safety of the local workforce. Cheers, OtL

 

[Crazy Leica Fox]

I would like to put in a plug here for the Cosina 50/3.5 Heliar. An almost tiny lens (mine is Nikon S but used on my M's with an adapter), it is an extraordinary performer. Sharp, creamy bokeh, old-timey to a degree, but wonderful images. With something like an M10, f/3.5 is enough. The only downsides are the rotating barrel and lack of click stops, but one adjusts.

The 50mm f/3.5 Heliar is one of my favorite lenses! I picked up a Nickel LTM, sometimes referred to as version III, specifically for its better handling: It's collapsible and becomes very tiny, and it has aperture click stops. However, the barrel still rotates when focusing. Others might feel the new, M-mount conical "version IV" is the best because it will have the latest coatings, but the Nickel LTM is only a decade old so I figure the differences are minimal 😉.

 

[lcpr]

Ergo, why do people still buy newly made lenses with flint glass from China? It can't be their concern for the environment, nor the safety of the local workforce. Cheers, OtL

To be as close as possible to the original lens in the context of making a replica.

I honestly doubt we'd be able to tell the difference if LLL (Light Lens Lab) substituted the flint glass with unleaded glass that performs similarly.

 

[Erik van Straten]

From Kevin's flickr (links below). Flint glass was originally made using lead, but lead doesn't necessarily have to be used and is mostly substituted with something more environmentally friendly these days.

Thank you Jon for this info; it is excactly what I wanted to say.

"If different glass is used, then the formula must be changed too. Why they choose for flint glass in the first place?
Btw, a complete lens never contains only one kind of glass. Many Leitz lenses (and others) from the fifties and sixties contain four or five different kinds of glass.
Because of environmental measures the use of many of those glasses is now forbidden.
The use of lead containing flint glass in this lens must be seen as a kind of experiment as I understand it.
The "normal" production later on will be of glasses without lead or other heavy metal in them if I understand this well."

Erik.

 

[jonmanjiro]

Ergo, why do people still buy newly made lenses with flint glass from China? It can't be their concern for the environment, nor the safety of the local workforce. Cheers, OtL

To be as close as possible to the original lens in the context of making a replica.

↑ this. Plus, of the "unsavory additives" that can be added to glass to achieve the required refractive index, lead oxide is one of the more mundane ones. People are generally ok with drinking out of flint lead aka lead crystal glasses after all.

 

[Erik van Straten]

People are generally ok with drinking out of flint lead aka lead crystal glasses after all.

But not from lead glaze on earthenware; this is forbidden in the EU for some time now.

Erik.

 

[Out to Lunch]

of the "unsavory additives" that can be added to glass to achieve the required refractive index, lead oxide is one of the more mundane ones

To clear things up, what substance is used in these new, cheap Chinese made lenses to 'achieve the required refractive index'? If it's not lead oxide or some other nasty stuff, I might buy one. Cheers, OtL

 

[raid]

But not from lead glaze on earthenware; this is forbidden in the EU for some time now.

Erik.

I recall many years ago hearing of crystal glass made in Czechoslovakia where "the good glasses" were had lead content.

 

[jonmanjiro]

To clear things up, what substance is used in these new, cheap Chinese made lenses to 'achieve the required refractive index'? If it's not lead oxide or some other nasty stuff, I might buy one. Cheers, OtL

Leaded flint glass is made with lead oxide.

All this nervous energy. I could not be bothered.

Good thing you could not be bothered, eh.

 

[Out to Lunch]

I am not bothered by the nervous ''Kevin, have you received my e-mail, Kevin, have you"? I am bothered by stuff on the cheap with lead oxide in it, eh.

 

[Erik van Straten]

I am bothered by stuff on the cheap with lead oxide in it, eh.

The alternative is aspherical glass, but aspherical lenses are usually much larger. I'm interested in how they will solve this problem.

When you want a very good, small, cheap and fast 35mm lens get one now I would say. The original 35mm 8 elements is priceless now.

Erik.

 

[Out to Lunch]

I am fine with my mundane Zeiss 2/35. Even though, I'd rather have my, now wobbly Zeiss 2.8/28 fixed instead.

 

[aizan]

They’re using an old batch of flint glass that’s been lying around for years. This has been covered.

 

[Out to Lunch]

This has been covered

Well, that solves the problem, then. Covered when and by whom. Cheers, OtL

 

[f.hayek]

They’re using an old batch of flint glass that’s been lying around for years. This has been covered.

I think even Red China is outlawing leaded glass.

_________
“We hold these truths to be self evident, that all Men are created equal...”
-T. Jefferson

 

[Out to Lunch]

"Red China"? Which planet are you living on.

 

[f.hayek]

"Red China"? Which planet are you living on.

The same one you’re on. It’s to distinguish it from the Republic of China on Taiwan. The PRC isn’t a Republic, doesn’t belong to the people nor does it encompass all of China. It isn’t even a Communist State, really. But it does have a big red flag.😎p

 

[jarski]

The answer is probably somewhere in past 68 pages, but am asking anyways 😀 flint glass version is still available to buy from somewhere?