Emil Busch unknown lens

[arri]

I got this interesting lens a few month ago for small money from an old photograper.

It is an Emil Busch 20cm (8") Quarzlinse (quartz glass lens)
It has two star shape apertures with the old German aperture values f/6.3 and f/9.0
Without the apertures it has a speed of f/4.5

Also a Filter adapter (?) for A51mm filters and a Carl Zeiss yellow filter comes with it and a blue filter rom AGFA as well.

I tested the glass and it is real a quartz glass lens element and the focus is 200mm.
Mounted in the rear thread of a Compund III shutter.

The shape of the aperture speaks for a portrait and landscape lens, a softfocus lens like the Oskar Zwierzina Plasticca lens but with the differents of the front aperture and the special glass.

I know, after reading the book from Michael Neumueller, that the star shape apertures are the best choice for single glass elements lenses and I realised it for my 270mm quartz glass lens too.

Also I know that the Hanover Company made a quartz glass softfocus lens in the 1920th, the Kalosat lens.
Carl Struss offered hin softfocus lens with optional quartz glass.

This kind of glass makes sense when you work with wet or dry plates which are only sensitive for blue and ultraviolet lights.
With ortho and pan material this glass gives a special kind of softness.
With yellow filter it can be use only with ortho- and panchromatic material.
The blue filter with blue light sensitive plates and films only, I guess.

I tested it only on the ground glass and it has a very nice rendering and I can´t await to see the first samples taken with it.

[Steven Tribe]

Hanovia.
There is also a Steinheil series of quartz LF lenses.
Dr. Klaus Schmitt was active here around 2009/10 with this info in his search for a Kalosat!

[arri]

Hanovia.
There is also a Steinheil series of quartz LF lenses.
Dr. Klaus Schmitt was active here around 2009/10 with this info in his search for a Kalosat!

Oh sorry, you are right. The name of the company is Hanovia.
Steinheil sold a few quartz glass lenses but I´am not sure that they were the maker of it.
The same with this Busch lens. Maybe all of this quartz glass elements were made in Jena by Carl Zeiss.
Zeiss made UV quartz and sodiumchloride glass lenses and they are listed in the 1930th in the catalogues.

This are very special lens elements, very expensive, in the past and today as well.

I start today to make some table tops with this lens.
No so easy to focus it.
When I have developed the negative I want to show it here.

[Steven Tribe]

More likely originated at Otto Schott who was best buddies with Carl Zeiss at Jena.

[arri]

My information is that Zeiss made the Quartz and Sodium Chloride lenses in house.
Schott delivered the standard optical glasses but maybe my infos are not correct.

In 1989 Zeiss Jena were able to let grow monolithic quartz cristals with a max weight of 1kg. No one else in the world were able to do that.
Zeiss West wanted this knowledge like the devil wants the soul. They got it after the wall were down.

This is a very special glass, I guess it is more important for microscopic lenses and other deep UV light usage.