When Xenon is a Xenar!

I have a pre-war Kodak Retina IIa (type 150) with the Schneider

Xenon 2,8/50.

 

I thought the lens looked much different from the post-war Xenon

on my IIc.

 

In front of the stop there are three air-spaced elements, and behind

the stop there's a cemented pair.

 

It's clearly the FIVE ELEMENT XENAR, and not a Xenon as the six

element Gauss-design we have learned to know.<div></div>

Before the war, the Xenar was limited to 2,9. To be able to make a high quality 2,8 version, they split the first element in two. That's the five element Xenar.

 

Schneider redesigned the Xenar after the war, so the later 2,8 version is a four element lens.

 

The illustrations above are from Schneiders 25'th anniversary book from 1938.

I'm no expert but the Schneider vintage lens website only shows Xenars as 4 element in 3 groups and the Xenons as 5 in 4 groups or 6 elements in 4 groups.

The five element 2,8 Xenar was only made in small quantities, before the war. It was available in 50 and 75 mm. There's no information about it on their website.

Patric, what a wonderful discovery! I could never imagine a Xenar with five elements. Halleluja!

Hmmm. Does this explain the bizarre statement in Kehoe's (spelling? can't find the wretched pamphlet now that I need it!) Collector's Guide to Retinas to the effect that the Xenars in Retina Ib and IB (small and large b) cameras have five elements? I confronted that statement with my cameras (one of each) and they rejected it. Reflection counting found 4 strong reflections in front of the diaphragm, 2 strong and 1 weak behind, all is in a 4/3 tessar type.

 

Among pre-WWII Xenars, the Vade Mecum mentions a triplet Type D f/3.5 "for small cameras only" and says that the f/2.9 may have had five elements but that since the authors hadn't seen one they couldn't be sure. Also says, with reference to a 50/2.9 on a Baldinette that they saw and were convinced was a 4/3 tessar type "but the advert. in B.J.A. 1937 p664 refers to Xenar as 4 or 5 glass (and this is likely to be the 5-glass if any was)." They also refer to a pre-WWII S-Xenar, more or less a tessar with a split front element and engraved, they say, Xenar, not S-Xenar.

 

Lotta confusion out there.

 

Cheers,

 

Dan

If you can read german :-)

 

"F�r die speziellen Zwecke der Universalphotographie mit kleinen Bildformaten (bis 6 x 6 cm) haben wir ausserdem eine Sonderkonstruktion, das Xenar f: 2,8 geschaffen, in der Form eines f�nflinsigen, halbverkitteten, unsymmetrischen Anastigmaten von besonders hoher Lichtst䲫e und bester Koma-Korrektur. Hier�ber steht en Sonder-Prospekt auf Anforderung zur Verf�gung".

 

Xenar 2,8

 

5 cm

 

7,5 cm

Maybe this is more readable:

 

"Fuer die speziellen Zwecke der Universalphotographie mit kleinen Bildformaten (bis 6 x 6 cm) haben wir ausserdem eine Sonderkonstruktion, das Xenar f: 2,8 geschaffen, in der Form eines fuenflinsigen, halbverkitteten, unsymmetrischen Anastigmaten von besonders hoher Lichtstaerke und bester Koma-Korrektur. Hierueber steht en Sonder-Prospekt auf Anforderung zur Verfuegung".

Dan Fromm wrote: "They also refer to a pre-WWII S-Xenar, more or less a tessar with a split front element and engraved, they say, Xenar, not S-Xenar".

 

I got a xerox-copy of a page from some Schneider book, and the five element Xenar was called "Super-Xenar", hence the "S-Xenar". (Not to be confused with the four element "S-Xenar" on some Rollei 35 cameras).

 

I don't think the 2,9 Xenars had five elements. Only a few 2,8 Xenars, but it seems like some of them alse were engraved "Xenon".

 

Hmmmm, should I load my Retina with film and take my first test roll?

<blockquote>

<i>

"Fuer die speziellen Zwecke der Universalphotographie mit kleinen Bildformaten (bis 6 x 6 cm) haben wir ausserdem eine Sonderkonstruktion, das Xenar f: 2,8 geschaffen, in der Form eines fuenflinsigen, halbverkitteten, unsymmetrischen Anastigmaten von besonders hoher Lichtstaerke und bester Koma-Korrektur. Hierueber steht en Sonder-Prospekt auf Anforderung zur Verfuegung."</i></blockquote>

Translates to:<p>

"Furthermore, for the specific needs of all-purpose photography in small formats (up to 6x6cm) we did create a special design, the Xenar f/2.8, in the mold of a five-element, half-cemented (?), asymmetrical anastigmat with an exceptionally large aperture and best coma correction. An extra brochure is available on request."

There are also the pre WW2 Retina 5cm F3.5 Ektars; non camerosity serials; that were actually made by Schneider; and are a 4 element 3 group standard "Tessar type design"<BR><BR>

Translates to:

"Furthermore, for the specific needs of all-purpose photography in small formats (up to 6x6cm) we did create a special design, the Xenar f/2.8, in the mold of a five-element, half-cemented (?), asymmetrical anastigmat with an exceptionally large aperture and best coma correction. An extra brochure is available on request."

 

Halbverkittet means "partially cemented" or "with some cemented elements". When lens coating was not available, lens designers tried to reduce the number of glass-to-air-surfaces by using a low number of elements, or cement together as many as possible (I think some early Planars have three elements cemented together). A lens with a single cemented element was called "halbverkittet".

To add to the confusion - "the Vade Mecum mentions a triplet Type D f/3.5 "for small cameras only"" - I have one of these, a 150mm f:3.5. Not exactly for a "small camera"? Unless they counted 9x12cm cameras as "small". Unlike other Xenar lenses the front element is positive, with an uncemented pair of correction elements behind the shutter...

To add to the confusion - "the Vade Mecum mentions a triplet Type D f/3.5 "for small cameras only"" - I have one of these, a 150mm f:3.5. Not exactly for a "small camera"? Unless they counted 9x12cm cameras as "small". Unlike other Xenar lenses the front element is positive, with an uncemented pair of correction elements behind the shutter...

Hi all,

 

I have an old Weltax with a 2,8/75 Xenar, uncoated. The reflections in the front part clearly indicate 3 elements. The back part has two elements. Pictures are really not bad, you might look here:

http://pg.photos.yahoo.com/ph/stainer_de/my_photos

 

My second weltax has the 3,5/75 coated Tessar , pictures will be made tomorrow...I only got it three days ago. I will do a parallel comparison with both cameras.

pictures will follow..

 

Rainer Wagner

Ole: I also own a 150 3,5 Xenar in a dialset compur mounted in a certotrop plate camera. The rear group is clearly an air spaced pair, but I am not sure about the frontal one: it seems to be a cemented pair, judging by the number of reflections. Could be also a D-type Xenar?

 

Is there any indication of a "D" type of Xenar in yours?. In mine:

 

Xenar f:3.5 F=15 cm DRPa Jos. Schneider & Co Kreuznach N? 284456

 

By the way, this lens is quite soft in the borders, even at f22. Regards

Javier, my Type D is very clearly marked as such: "Xenar Typ D 1:3,5".

 

The front group/element is more strongly curved than other Xenars, and the rear group does not focus.

Rainer, the 25'th jubilee book from Schneider 1938 says that the five element 2,8 Xenar was made in 50 and 75 mm. I have also a pre-war Weltax with a 2,8/75 Xenar, but mine seems to be a four element lens, with only two elements in front of the aperture. :-/