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Yann E.
Joined: 22 Feb 2012
Posts: 184
Location: France
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 Posted: Thu Feb 23, 2012 4:54 am Post subject: |
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| ChrisR wrote: | | Quote: | | First, all "traditional" Xenon lenses (i.e. before the name became a marketing gimmick instead of a lens layout designation) are 6/4 Planar type lenses (single outer elements, inner cemented doublets), as opposed as 6/4 Plasmat types (outer cemented doublets, single inner elements) like the Symmar line. |
That's interesting, the question has to be "why?", I mean what's the advantage of one design over another - any idea? |
First, I have to make a small clarification : although the original 1897 Planar was the 6/4, many later Planar lenses were of an altered 5/4 design (Zeiss Biometar design, Xenotar for Schneider) and the 6/4 became the Biotar (by Zeiss designations). The "Planar" name having become famous, Zeiss later used it for either 6/4 (original Planar, Biotar), 5/4 (Biometar) and 6/5 (Voigtländer Ultron variants) designs + all their later variants.
When I refer to the "Planar design", I mean "original Planar 6/4" only.
I'm not very competent in optics, but from what I have gathered it seems that the planar design allows greater apertures and optimal aperture closer to the max aperture, and less vignetting at large apertures.
This is at the cost of less coverage and less resistance to diffraction than the Plasmat design, which in turn doesn't allow large apertures because of excessive vignetting. This is why Plasmats are the dominant layout in large format photography (coverage is needed for tilt/shift, long exposures are not a problem when working on a tripod) and enlarging (larger image circle->shorter enlarger column for the same print size).
BTW, the only Plasmats over f4 that I know of are the Fujinon EP 3.5/50 and most 2.8/50 enlarging lenses.
| ChrisR wrote: | 35mm f/2.0 Mid 1977 (looks much like the one above)
28mm f/2.0 Approx 1943 (looks older!) |
I suppose the 28mm is uncoated then ?
| Planapo wrote: | But Chris' Xenon 2/40 pictured above, was manufactured between 1995 and 1996.
Hmm,... 
--Betty |
Wild guess : the lens was discontinued but optical groups were still in stock and were used for APS enlarging lenses when Schneider ran out of stock for the already phased-out Componon 4/35 which had no replacement in the new Componon-S line ? From the blueish reflection on the front lens the lens seems single-coated, AFAIK all current Schneider lenses in 1995 were already multi-coated so that could support the "old stock" hypothesis...
BTW Chris, not wanting to look like a vulture circling above a carcass here, but should you ever want to get rid of either the 35mm or 40mm...  |
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Planapo
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Joined: 07 Nov 2006
Posts: 1423
Location: Germany, in the United States of Europe
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| Posted: Thu Feb 23, 2012 11:28 am Post subject: |
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Yann, sorry, in my posting above I forgot to welcome you, as it is good tradition on photomacrography.net.
So here we go now: Yann, a belated welcome aboard! 
| Quote: | | when Schneider ran out of stock for the already phased-out Componon 4/35 which had no replacement in the new Componon-S line ?... |
Perhaps I misunderstood you, but besides the Componon-S and Apo-Componons, there are the (just) Componons like the 4/35, 4/28 and 4/40 that are currently still sold by Schneider, and they can be had in various barrels.
--Betty |
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Yann E.
Joined: 22 Feb 2012
Posts: 184
Location: France
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| Posted: Thu Feb 23, 2012 12:25 pm Post subject: |
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| Planapo wrote: | Yann, sorry, in my posting above I forgot to welcome you, as it is good tradition on photomacrography.net.
So here we go now: Yann, a belated welcome aboard! |
Thank you...but I forgot to introduce myself, which is also a tradition on most civilized forums...  Where should it be done BTW ?
| Planapo wrote: | | Quote: | | when Schneider ran out of stock for the already phased-out Componon 4/35 which had no replacement in the new Componon-S line ?... |
Perhaps I misunderstood you, but besides the Componon-S and Apo-Componons, there are the (just) Componons like the 4/35, 4/28 and 4/40 that are currently still sold by Schneider, and they can be had in various barrels.
--Betty |
My mistake, they are no longer listed on Schneiderkreuznach.com but are still available on Schneideroptics.com, which I forgot to check...I just assumed they had been phased out like the rest of the Componon line.
Doesn't mean my "we have the optical blocks, let's sell them as enlarger lenses" theory is wrong, but it now is seriously weakened...  |
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ChrisR
Joined: 14 Mar 2009
Posts: 3051
Location: Near London, UK
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| Posted: Thu Feb 23, 2012 12:29 pm Post subject: |
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Well there's the "Community members and friends" section
I must say that your English is remarkably good if you're a native French speaker, or is it that you're a
Xenophile |
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Photo-DIY
Joined: 04 Apr 2011
Posts: 31
Location: Germany
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| Posted: Thu Mar 22, 2012 3:49 am Post subject: |
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| Yann E. wrote: | ...
Wild guess : the lens was discontinued but optical groups were still in stock and were used for APS enlarging lenses when Schneider ran out of stock for the already phased-out Componon 4/35 which had no replacement in the new Componon-S line ? From the blueish reflection on the front lens the lens seems single-coated, AFAIK all current Schneider lenses in 1995 were already multi-coated so that could support the "old stock" hypothesis...
... |
As far as I know the older lens designs that are still sold, are still producted with the same old coating. The Xenon 25/0.95 has an old probably"ineffective" coating - for visible light. But for infrared those old coatings are great!
With someting like a 25mm screw mount on the back I would suppose it is a CCTV / machine vision lens. There Schneider Kreuzanch has many products. And some products that are not listed on their website.
BTW: Schneider Kreuznach`s archive is worth visiting, just for the joy with old lenses:
http://www.schneiderkreuznach.com/archiv/archiv.htm
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ChrisR
Joined: 14 Mar 2009
Posts: 3051
Location: Near London, UK
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| Posted: Thu Mar 22, 2012 4:16 am Post subject: |
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| Quote: | | With someting like a 25mm screw mount on the back I would suppose it is a CCTV / machine vision lens. |
I'm pretty sure they used to use the 25mm mount for regular enlarger lenses, I've had a a couple for 30 years or so, which weren't new then. The 25 - 39mm adapters were very common. |
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Photo-DIY
Joined: 04 Apr 2011
Posts: 31
Location: Germany
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| Posted: Thu Mar 22, 2012 5:41 am Post subject: |
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| ChrisR wrote: | ..
I'm pretty sure they used to use the 25mm mount for regular enlarger lenses, I've had a a couple for 30 years or so, which weren't new then. The 25 - 39mm adapters were very common. |
I have one or two enlarger lenses with a small mount too, could be 25mm screw mount. But somehow I think (guess) in the 90s all enlarger lenses are M39 or bigger.
I think the enlarger lens idea is possbile, but some special CCTV/Machine Vision seems to be an option too.
The lack of an focussing helicoid and the direction of the iris letters are arguments for the enlarger lens theory.
But f/2, Xenon and probably C-Mount are more like CCTV/machine vision. And for such applications I have seen some lenses that are customized to fit customers demands.
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Some own work - and a bigger list of DIY links |
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kds315*
Joined: 02 Feb 2009
Posts: 141
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ChrisR
Joined: 14 Mar 2009
Posts: 3051
Location: Near London, UK
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| Posted: Fri Aug 10, 2012 4:33 pm Post subject: |
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f/2.0 could make some sense for commercial "en-print" ( cheap small prints for amateurs), printing machines, as I said.
But my 28mm is dated 1943. I don't know what formats would have been in use then which would have called for it. Actually I hesitate to imagine what people were making lenses for at that time. 16mm movies?
What date is yours?
http://www.schneideroptics.com/info/age_of_lenses/ |
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kds315*
Joined: 02 Feb 2009
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