[LargeFormat] Wide field and Commercial Ektars

[Richard Knoppow]

----- Original Message ----- 
From: "Richard Knoppow" <dickburk at ix.netcom.com>
To: "f32 Large Format Photography Mail List" 
<largeformat at f32.net>
Sent: Wednesday, August 10, 2005 6:24 AM
Subject: Re: [LargeFormat] Wide field and Commercial Ektars


>
>
> -----Original Message-----
> From: Les Newcomer <LNPhoto at twmi.rr.com>
> Sent: Aug 10, 2005 5:56 AM
> To: f32 Large Format Photography Mail List 
> <largeformat at f32.net>, k4sb at niia.net
> Subject: Re: [LargeFormat] Wide field and Commercial 
> Ektars
>
> Very interesting. Does your '46 set say "Wide Field" or 
> "Wide Angle"
> Ektar.   I have a 135 and 190 also from '46 that say Wide 
> Angle, but
> these have a 000 serial number.
>
> While I'm still in negotiations with the owner, I'm aware 
> of a 14"
> Eastman Ektar.  Has all the markings and machining of a 
> Commercial
> Ektar (bright mount of aluminum, style of engraving) 
> accept its date
> code is EY (1940); hence the interest of the "Commercial" 
> introduction.
>
>   The Eastman Ektar is the same lens as the Commercial 
> Ektar but is not hard coated. Rather, it is soft coated on 
> protected surfaces. I am not sure of the exact date Kodak 
> began to hard coat civilian optics but it is about 1946. 
> The lens is still listed as the Eastman Ektar in the 1945 
> edition of the Kodak lens booklet.
>    Kodak changed the names of a number of its lenses 
> c.1947. Prior to this they made two series of Kodak 
> Anastigmat lenses, the 30 series, which were Tessars, and 
> the 70 series, which were dialytes. The 30 series were 
> discontinued about 1947 and replaced by Ektar lenses. The 
> Ektars were not the same design and are of somewhat 
> different focal length. The one exception is the No.70 
> Kodak Anastigmat, whcih was continued with the addition of 
> hard coating as the Kodak Ektar,  203mm, f/7.7   Kodak 
> also began calling its enlarging lenses Enlarging Ektars 
> or Enlarging Ektanon rather than Projection Ektar or 
> Anastigmats. Names like Anastar and Anaston for lower cost 
> lenses were also introduced in about 1947.
>   I believe that Kodak lenses serial numbered 000 are 
> prototypes.
>
>
>
> --
> Richard Knoppow
> dickburk at ix.netcom.com
> Los Angeles, CA, USA

   The above was posted from work by memory. I am at home 
now.
   The 1945 edition, 1946 printing, of "Kodak Lenses, 
Shutters and Portra Lenses" a booklet included in the _Kodak 
Reference Handbook_ has the Eastman Ektar and No.70 Kodak 
Anastigmat included  as well as many other Kodak Anastigmat 
lenses. The Wide Field Ektar is not listed. The Third 
Edition, dated 1948 lists the Commercial Ektar and Wide 
Field Ektar as well as the changed names for the Anastmat 
series.
   Evidently, Kodak began hard coating lenses c.1946. The 
"Second Edition" of the above booklet, undated but probably 
1945, describes the Eastman Ektar coating in this way "The 
inner glass-air surfaces are treated by a special process 
which reduces reflections." In the 1946 book this becomes 
"The glass-air surfaces are treated..." The early coatings 
used on these and a few other Kodak lenses (the lens on the 
Medalist and for the Ektra camera for instance) were too 
soft to expose them to even ordinary cleaning. I don't know 
what process Kodak used on these earlier lenses but it was 
likely an earlier version of vacuum coating before the 
discovery of baking in the vacuum chamber. Or, perhaps it 
was a chemical dip coating. Coatings of the latter type were 
known and were developed at various labs, especially RCA. 
Chemical bath coatings can be wiped off the lens. Unbaked 
vacuum coatings are harder but will not withstand routine 
cleaning and wear. Baked vacuum coatings are very hard.
   There is a gap in time between the various editions of 
the lens booklet. I don't have all the printings although I 
do have both a first and second printing of the 1946 
booklet. Its possible that the WF Ektar is listed in a later 
printing or, perhaps, was not listed until the booklet was 
completely revised in 1948. The date code on the lens is the 
best indicator of its date.
   Kodak built a great number of lenses for the military and 
for special purposes. Also, some prototype lenses have come 
on the market. As stated before I believe 000 serial numbers 
are prototypes not intended for sale.
   Again, the Eastman Ektar and Commercial Ektar are the 
same lens under different names. The medium format Kodak 
Anastigmats and Kodak Ektars are not the same lenses, in 
fact, both were made for a time.
   There is a very good history of vacuum coating for optics 
at the Society of Vacuum Coaters site at http://www.svc.org

---
Richard Knoppow
Los Angeles, CA, USA
dickburk at ix.netcom.com