Eastman Ektar 14 inch: serial number and coating

[NormaN]

Hello all

I recently bought an Eastman Ektar 14 inch.

According to "CAMEROSITY" it is from 1940, uncoated. Normally the two letters are followed by a three digit number. Some models before about 1945 have the letter "K" appended. After that they are "Lumenized" (Weston uses a 1946 model in the attached film).

https://www.youtube.com/watch?v=g4aE2f07ON4

Does anyone know what the letter "K" means? Is this an indication of the soft coating on the inner surfaces?

I read somewhere that magnesium fluoride was used. Or is it "K "alzium fluoride?

In addition to the photo of the lens and the film, I have attached the second page from a brochure from 1938 where the "Eastman Anastigmat Ektar f.6.3" is advertised.

Thank you for your help!

[Greg]

Something also to be aware of: In 1961 Burke & James had a "Lenskoting Department". "Lenskoting is the modern surface treatment for all glass-air surfaces." per their 1961 catalog. "The service is nominal - service is prompt." I once owned a 14" Ektar that was "Lenskoted" by B&J. The only way that I knew that was because a receipt for their "Lenskoting" service was included with the lens. I did once read that their "Lenskoting" Ektars was very popular back then. Did it make a difference with Ektars? I say questionable.

[David Lindquist]

My Kodak Reference Handbook copyright 1945 indicates that many (but not all) of their Ektar lenses were coated on the internal surfaces. In particular the Ektars for the Ektra camera and the Eastman Ektars were coated internally. Doesn't say what the coating was. It's my understanding that it was too soft to use on external surfaces. From a cursory google search it looks like magnesium fluoride coatings are reasonably hard so I'm guessing it was something else. Hoping someone will come along who knows what it was and also why they didn't go to magnesium fluoride coatings right away.

The Eastman Ektars became the Commercial Ektars; the Commercial Ektars had both internal and external surfaces coated. The film's copyright is 1948 so that could be a Commercial Ektar. My hunch is Eastman Kodak provided Weston with a Commercial Ektar not wanting their Kodachrome subjected to the vicissitudes of Edward's uncoated Turner-Reich Anastigmat.

Up into the 1970's there was a place in Pasadena called Pacific Universal Products that did lens coating, they called their process "Acra-Coat" (not sure of the spelling).

David

[Mark Sampson]

This question came upon Photrio a while back. EK changed the "Eastman" name to "Kodak" on those lenses post-WWII, when civilian production resumed. Those lenses were coated, where the "Eastmans" had not been. In addition, EK continued production of "Anastigmat" lenses, similar to the Ektars but uncoated.

There was a great deal of speculation on Photrio... but no one was able to find an answer about the mysterious "K". I suggested that the OP over there contact Todd Gustavson, the technology curator at the George Eastman Museum, which holds Kodak's patent museum (along with a great deal of EK's history). The last time I looked, the OP had not received a reply. Someone else suggested a search in the library at the University of Rochester, which holds other Kodak archives; I don't know if anyone's done that yet.

I worked for Kodak as a technical photographer and lab rat from 1984-2004, and then for ITT until 2010, after EK sold my division to them.. I was based at the Hawk-Eye plant, where those lenses had been made. We used many Ektar lenses on the job; but all the people who had made the Ektars must have been long retired by then.
I even had a 14" Eastman Ektar in its original ebony box as a desk ornament. It may never have been used (or left the building where it was made). That one was EY 000, I recall, but no extra "K". We may never know.

[Dan Fromm]

Alzium? Wozzat?

[NormaN]

Hi all Dnke you for the interesting background stories.

@Greg
You mean that for the early versions someone outside Eastman did the coatings?

@David:
Found a photo of an early model (see attached). There are no prefixed letters here, just the 3 digits and the ominous K appended.

@Mark
Thanks for the hint about Photrio (haven't found it yet).
I would also like to browse the archives or the George Eastman Museum, preferably on site (unfortunately I live far away in Switzerland). Maybe I will make contact by mail....

@Dan:
That was just pure guesswork
magnesium fluoride was used as a coating
Maybe calcium fluoride was also used and hence the K for "Kalzium"
Or K for Kodachrome
Or K for Kodatron / something about flash use

[Greg]

You mean that for the early versions someone outside Eastman did the coatings?

Burke & James Inc in Chicago, Ill. was a huge photographic equipment store in the 1960s. They advertised that they were the "World's Finest Photographic Equipment (store) for over 64 years" back in 1961. They offered a full range of photographic equipment, custom lens grinding and polishing, Lenskoting, quality control measurements, precision engraving & calibration, modern auto-collimation, and more. They also had a huge lens bank of vintage and new lenses. Burke & James was also a prime and major contractor for the United States Government. As far as I know Eastman Kodak did not use them for coating their lenses. My 14" Ektar is from 1947. After the three digits is the capital letter L with a circle around it. I was told by the original owner of the lens that this indicated that the lens was coated by Eastman Kodak. Sidebar: The original owner also told me that he only used the lens a few times which makes sense since the lens today is in absolutely mint to like new condition.

[David Lindquist]

Hi all Dnke you for the interesting background stories.

@David:
Found a photo of an early model (see attached). There are no prefixed letters here, just the 3 digits and the ominous K appended.

Very interesting example. It's labeled "Eastman Anastigmat" and looks like a precursor to the Eastman Ektar, 14 inch f/6.3 lens. I had not previously known of such a lens but my Eastman Kodak literature for the late 1930's is, well, non-existent. In any case I don't know what the "K" is about.

I think Kodak started using the "CAMEROSITY" code in 1940.

David

[David Lindquist]

Burke & James Inc in Chicago, Ill. was a huge photographic equipment store in the 1960s. They advertised that they were the "World's Finest Photographic Equipment (store) for over 64 years" back in 1961. They offered a full range of photographic equipment, custom lens grinding and polishing, Lenskoting, quality control measurements, precision engraving & calibration, modern auto-collimation, and more. They also had a huge lens bank of vintage and new lenses. Burke & James was also a prime and major contractor for the United States Government. As far as I know Eastman Kodak did not use them for coating their lenses. My 14" Ektar is from 1947. After the three digits is the capital letter L with a circle around it. I was told by the original owner of the lens that this indicated that the lens was coated by Eastman Kodak. Sidebar: The original owner also told me that he only used the lens a few times which makes sense since the lens today is in absolutely mint to like new condition.

The "L" in the circle stands for "Lumenized" which was Kodak's name for applying a hard anti-reflective coating to their lenses. Similarly Wollensak lenses had a "W" in a circle for "Wocote", their name for this process. My thanks to Dugan for correcting my spelling here.

I think Bausch & Lomb used the term "Balcoated" (again not sure of the spelling), don't know if they had a symbol they engraved on the lens mount for this.

Schneider marked their coated lenses with a red triangle and Zeiss, famously, marked theirs with a red "T". Schneider and Zeiss eventually dropped these markings. Zeiss revived the red "T" adding an asterix ("T-star") for their multicoated lenses.

Photographic lenses, at least those of quality, seem to have been universally (or nearly so) hard coated beginning shortly after the end of World War II which makes me think the technology for doing this en masse was developed during the war. I have seen statements that Zeiss was doing this before World War II but not on all their lenses.

David

[Dugan]

Wollensak named the coating " Wocote".