Ok, that would make it of the Opic/Xenon type which was roughly of the same vintage, the design which was refined to become the basis of just about every "normal" f/1.8-2 lens in 35 mm photography... Eric Goldstein On 10/3/07, Richard Knoppow <dickburk@xxxxxxxxxxxxx> wrote: > The diagram in the Kodak lens booklet shows a six > element conventional Biotar or Opic type. I can't find this > lens in LensView but I may be able to find something in a > Google patent search. The earliest Kodak Biotar in LensView > is a patent applied for in 1937 and issued in 1940, from the > diagram its not the same lens although it is an f/2 lens. I > don't think Kingslake shows the Bantam Special lens. I don't > know if the earlier versions of this lens were coated but > the 1946 printing of the 1945 edition states that the Bantam > lens and the Medalist lens are "treated on glass air > surfaces to reduce flare." This may be a hard coating but > Kodak was applying soft coating to the inner surfaces of > lenses from about 1940. > This is from a _Kodak Reference Handbook_ I bought at a > sale last week-end. It has several Kodak bulletins in it, > one of which is for _Kodak Luminized Enlarging Lenses_. If I > read the date code on the back right it was published 5-48. > It shows a picture of a vacumm coating machine and a very > brief description of coating. I am pretty sure Kodak began > using the trade-name of "Luminized" about 1946, however, its > not used in the booklet described above. However, there is a > slight revision of the text from the 1945 edition: the > lenses called Eastman Ektars (later called Kodak Commercial > Ektars) are described as having anti-flare coatings on > _inner_ glass-air surfaces in the older edition and simply > as being treated for anti-flare in the later edition, > leading me to believe that these were hard coatings even > though the name "Luminized" was not yet applied. > Further, Kodak was one of the primary companies > involved in the research into anti-reflection coating during > WW-2. Kodak and RCA were very early developers of various > means of lens coating going back to the early 1930's. RCA's > interest may have been due to its interest in photographic > sound recording. In any case, there are some early articles > on coating in the _RCA Review_, RCA's scientific house > organ. > Zeiss had developed a method of vacuum coating about > 1935 but I don't think it was hard coating. The trick of > baking the coating in vacuo in the coating machine was > developed during WW-2 as part of the Signal Corps research. > > --- > Richard Knoppow > Los Angeles, CA, USA > dickburk@xxxxxxxxxxxxx > > --- > Rollei List > > - Post to rollei_list@xxxxxxxxxxxxx > > - Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe' > in the subject field OR by logging into www.freelists.org > > - Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with > 'unsubscribe' in the subject field OR by logging into www.freelists.org > > - Online, searchable archives are available at > //www.freelists.org/archives/rollei_list > > --- Rollei List - Post to rollei_list@xxxxxxxxxxxxx - Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe' in the subject field OR by logging into www.freelists.org - Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with 'unsubscribe' in the subject field OR by logging into www.freelists.org - Online, searchable archives are available at //www.freelists.org/archives/rollei_list