[rollei_list] Re: Thanks Richard! (was: recoating and polishing the Xenotar lens)
- From: Ardeshir Mehta <ardeshir@xxxxxxxxxxxx>
- To: rollei_list@xxxxxxxxxxxxx
- Date: Tue, 12 Apr 2005 11:32:53 -0400
Thanks again, Richard, for the wonderfully informative post!
+++++
On Tuesday, April 12, 2005, at 04:06 AM, Richard Knoppow wrote:
> Opton was used for a time as a trademark for lenses made by the Zeiss
> factory in Oberkochen. This was the result of legal action about who
> owned the name "Zeiss". For at least a part of this time the original
> Zeiss plant in Jena could not put the name Zeiss on its lenses. Marc
> Small can give you the exact details and dates.
>
> The quality of the lenses produced at the two parts of Zeiss were
> probably similar but the detailed designs were probably not identical.
> Jena and Oberkochen each had their own designers.
>
> The Xenar is a Tessar _type_ lens but is an individual design.
> Actually, both Zeiss and Schneider made several versions of these
> lenses over their lifetimes.
>
> The 5 element lens made by Zeiss as the Planar and by Schneider as the
> Xenotar are similar but not the same. Actually Zeiss Oberkochen made
> at least two versions of this lens and Zeiss Jena made another called
> the Biometar. While there has been a long standing controversey about
> the relative merits of these lenses they probably are closer in
> average performance than the individual variation from lens to lens of
> any one type. The second Zeiss version of the Planar was probably made
> to reduce the difficulty of making the original which had a very steep
> and thin element cemented to another. Also, the spacing between the
> front component and the second element is very small and nearly
> touching so it must have been very critical.
>
> The general opinion of the Xenar is that its the equal of the Tessar.
> I have two Rolleis (cord and flex) with Xenars and both are very sharp
> lenses. Actually, the one on the cord seems to be exceptional.
>
> The f/2.8 Xenotar seems to be an exceptionally lens. I judge this
> because it reproduces textures in a way typical of very good lenses on
> a larger format. Also, this very fine detail holds up under
> magnification so its not an illusion of some sort.
>
> Before WW-2 Schneider was not known as a quality brand, after the war
> they seemed to have turned the company around completely and made
> excellent lenses with good quality control.
>
> There has also been a lot of controversey about the relative quality
> of the lenses made by the two halves of Zeiss. Because Zeiss
> headquarters, in Jena, wound up in the Russian Zone, and because a
> number of key Zeiss personal escaped to the U.S. Zone, two companies
> were formed, one in Jena and one in Oberkochen. These were really
> independant but made similar products under the same name. It is very
> difficult to judge the relative quality of the products (lenses,
> microscopes, etc.), but both companies had problems due to the
> aftermath of the war and the splitting up of the personel. Again, Marc
> is the expert in this area and I am sure will correct any mistatements
> I may have made.
>
> I should say that Rollei bought lenses from all three suppliers. I
> think Schneider was included because neither Zeiss could supply lenses
> at some point and because Schneider had improved its quality so much.
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