Mysterious M on a Kodak inner rim 12 inch f 4.5

[Dan Fromm]

And what does the "O" preceding the "EI" signify?

David

It isn't an "O," it is a circle with an "L" in it. This symbol means "Lumenized," Kodak-speak for coated. EI are the first two characters of the lens' serial number. If you have the right secret decoder ring you can translate EI into a two digit year. 47.

 

[grat]

It is an O. "O-EI 492 Ⓛ R Kodak Ektar Lens 7½ in. ƒ:4.5"

... I have no idea if my unicode efforts will pay off.

 

[mshchem]

It isn't an "O," it is a circle with an "L" in it. This symbol means "Lumenized," Kodak-speak for coated. EI are the first two characters of the lens' serial number. If you have the right secret decoder ring you can translate EI into a two digit year. 47.

There's A RING!

 

[David Lindquist]

It is an O. "O-EI 492 Ⓛ R Kodak Ektar Lens 7½ in. ƒ:4.5"

... I have no idea if my unicode efforts will pay off.

Thank you! And well done.

David

 

[David Lindquist]

It isn't an "O," it is a circle with an "L" in it. This symbol means "Lumenized," Kodak-speak for coated. EI are the first two characters of the lens' serial number. If you have the right secret decoder ring you can translate EI into a two digit year. 47.

My CAMEROSITY secret decoder ring would make this 1948.

David

 

[Gaston 012]

@grat , I am afraid I do not get it, Did you figure it out?

 

[grat]

@grat , I am afraid I do not get it, Did you figure it out?

No, I was referring to my efforts poking around in character sets in recreating as precisely as possible the markings on the lens-- unfortunately, I have no idea what the odd marks mean.

 

[Gaston 012]

Wellcome Doug, maye new blood is what is needed here!!!!!!!!!!!!!!!!

 

[Gaston 012]

Just when I was beginning to

to forget this stuff I saw this:
A new letter aded, the mystery continues!!!!!!!!!!!!!!!!!

 

[Murrayatuptown]

I was about to remark that at least the unexpected letters all were coincidentally part of the same CAMEROSITY reduced alphabet...until the K.

Was there another code word than CAMEROSITY in Europe?

Still doesn't help with significance...and they shouldn't mix US and 'other' code on the same article...so I have (had) nothing to contribute.

 

[grat]

Wiki says "CUMBERLAND" for English made lenses.

... so it must be true.

 

[Gaston 012]

@grat
Thanks, I did not know that.

 

[MarkS]

For the record, very few "Eastman Ektar" lenses were made. I've never seen a coated example- but I did have one of them as a desk ornament when I worked there. It was a !0" in barrel (as above) with a 1940 serial number. It was in its original ebony box, looked unused, and may never have left the building where it had been made.
It's probable that EK stopped making "Eastman" Ektars when wartime production took over, and postwar re-inntoduced them, coated, as Ektar and Commercial Ektar models.

I doubt if any of the people who worked making those lenses are still alive.
After 55-82 years, I think the knowledge of what those extra letters on the nameplate meant is lost for good.
One way to find out would be to contact Todd Gustavson, the technology curator at the George Eastman Museum. EK donated their patent museum and much paperwork to the GEM some years back. The information might be buried in there somewhere-who knows?

 

[Gaston 012]

@MarkS

This is great, you are the one that has given a good explanation with a possibility, albeit very small, that we are going to get to the bottom of it.
Do you want to try and contact this person ar do you want me to do it?
Your chances are better since you are an old "insider" but if you are busy I will give it a shot.
Gaston

 

[David Lindquist]

For the record, very few "Eastman Ektar" lenses were made. I've never seen a coated example- but I did have one of them as a desk ornament when I worked there. It was a !0" in barrel (as above) with a 1940 serial number. It was in its original ebony box, looked unused, and may never have left the building where it had been made.
It's probable that EK stopped making "Eastman" Ektars when wartime production took over, and postwar re-inntoduced them, coated, as Ektar and Commercial Ektar models.

I doubt if any of the people who worked making those lenses are still alive.
After 55-82 years, I think the knowledge of what those extra letters on the nameplate meant is lost for good.
One way to find out would be to contact Todd Gustavson, the technology curator at the George Eastman Museum. EK donated their patent museum and much paperwork to the GEM some years back. The information might be buried in there somewhere-who knows?

Regarding coating of lenses by Eastman Kodak in the earlier 1940's, there is this (extracted from something I posted in the past, maybe here, maybe LFPF):

Here's what my Kodak Reference Handbook, copyright 1940 and 1943, says about lenses being coated (or as they alternatively say, "treated"):
The six Ektars made for use with the 35 mm Ektra, focal lengths 50 - 153 mm: "Inner air-glass surfaces are coated to reduce reflections…"
The f/2 45 mm Ektar used on the Bantam Special: "Inner air-glass surfaces are treated to reduce internal reflections."
The description of the 100 mm f/3.5 Ektar used on the Medalist refers to "...coating the inner air-glass surfaces of the lens."
For the f/6.3 Eastman Ektars (forerunners of the Commercial Ektars, four lenses 8 ½ to 14 inch focal length), this reference says: "...inner air-glass surfaces are treated by a special process which reduces reflections…"
The descriptions in this reference for the 105 mm f/3.7, the 101 mm f/4.5 and the 127 mm f/4.7 make no mention of being "coated" or "treated" And likewise for the f/4.5 Kodak Anastigmats, six lenses, 5 ½ - 12 inch focal lengths and the 8 inch f/7.7 Kodak Anatigmat, no mention is made of being "coated" or "treated".
I recall hearing that during this era of coating by Eastman Kodak, because the coating material was so soft it was only applied to the internal surfaces.

David

 

[jimgalli]

"M" is for Magic. That lens can make better pictures than any other lens. A bargain at twice the price. Magic lenses are scarce. Even the little green men have a hard time finding me "M" lenses.

Serious guess; After the war Bausch & Lomb went to a numbering system that used letters and 4 numbers. Maybe Kodak was giving a "nod" to the new Bausch and Lomb coding for some reason. Sometimes military spec made the big makers get in line and perhaps an M code meant something equivalent to the military across the board of manufacturers. That's just a wild stab in the dark. Hope someone finds some old cataloguing that explains it.

 

[MarkS]

Gaston, I'll suggest that you contact Todd Gustavsson directly. I have no "in" at the GEM, and I'm sure he (and everyone there) would be happy to help. (And if you're ever in upstate NY be sure to visit!)
David, thanks for that info. Kodak published lots of information (like that) if you know where to look for it.
Jim, your idea is as plausible as any.
I just wish i'd never sold my 10" Wide Field Ektar and 14" Commercial Ektar (or my 8x10 Master Camera).

 

[reddesert]

Regarding coating of lenses by Eastman Kodak in the earlier 1940's, there is this (extracted from something I posted in the past, maybe here, maybe LFPF):

Here's what my Kodak Reference Handbook, copyright 1940 and 1943, says about lenses being coated (or as they alternatively say, "treated"):
The six Ektars made for use with the 35 mm Ektra, focal lengths 50 - 153 mm: "Inner air-glass surfaces are coated to reduce reflections…"
The f/2 45 mm Ektar used on the Bantam Special: "Inner air-glass surfaces are treated to reduce internal reflections."
The description of the 100 mm f/3.5 Ektar used on the Medalist refers to "...coating the inner air-glass surfaces of the lens."
For the f/6.3 Eastman Ektars (forerunners of the Commercial Ektars, four lenses 8 ½ to 14 inch focal length), this reference says: "...inner air-glass surfaces are treated by a special process which reduces reflections…"
The descriptions in this reference for the 105 mm f/3.7, the 101 mm f/4.5 and the 127 mm f/4.7 make no mention of being "coated" or "treated" And likewise for the f/4.5 Kodak Anastigmats, six lenses, 5 ½ - 12 inch focal lengths and the 8 inch f/7.7 Kodak Anatigmat, no mention is made of being "coated" or "treated".
I recall hearing that during this era of coating by Eastman Kodak, because the coating material was so soft it was only applied to the internal surfaces.

David

I have a 1946 printing of the Kodak Reference Handbook, and also a brochure for the Kodak Ektra - these books came with a Medalist II, and must have been acquired by its original owner. The Ektra ad brochure says "the inner surfaces of the lenses are treated by a coating process that imporves the clarity and brilliance of the negatives ..." as your source does. By the 1946 handbook, the Lenses section says:

- for the Ektra lenses, "Air-glass surfaces are coated to reduce reflections ..."
- for the Medalist and Bantam Special lenses, similar language about the air-glass surfaces are treated.
- in the sections describing the Ektar 105/3.6, 101/4.5, 127/4.7, they also say the "The air-glass surfaces are treated."
- for the Anastigmats on Kodak 35 and folding cameras, and the 5.5" to 12" Anastigmats, no mention of treatment.
- in the Eastman Ektar 8.5" to 14" section, they do say "The air-glass surfaces are treated by a special process which reduces reflections."

So as of 1946, Kodak was still calling them Eastman Ektars, but now asserted that (presumably all) air-glass surfaces were coated. I don't know when they changed to Commercial Ektars, but perhaps that could be figured out from the Camerosity serial number date codes.

 

[David Lindquist]

There's more on coating and Ektars here: http://www.bnphoto.org/bnphoto/KodakEktarsDB0a.htm
The "soft" coating only applied to internal surfaces was calcium fluoride, the harder coating which came in to routine use circa 1946 was magnesium fluoride.

Sniffing around eBay I came across two 127 mm f/4.7 Ektars from 1945 (ERxxx...) which do not have the circled "L" and two of the same lens from 1946 (EOxxx...) which do have the circled "L".

The website I've cited also indicates the University of Rochester holds some of Eastman Kodak's technical records.

David

 

[GKC]

Wasn't Mable the name of Rudolph Kingslake's pet Scottish Terrier?

 

[Gaston 012]

I finally sent a letter with the photos of the 3 lenses with extra letters to Mr Gustavson at the Eastman K museum
We shall see if we get and answer

 

[Gaston 012]

The letter was never acknowledged by the gentleman so, I presume he is no longer there or does not give a damn about our little problem.
It looks like we will never get to the bottom of these letters.

 

[David Lindquist]

The letter was never acknowledged by the gentleman so, I presume he is no longer there or does not give a damn about our little problem.
It looks like we will never get to the bottom of these letters.

That's too bad, but thank you very much for the follow-up.

David