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  1. #1

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    Lens seperation? what is it?

    Hey guys,

    Can anyone explain what lens seperation is? I've seen with vintage cameras that this is a problem.

    ToddB
    Last edited by ToddB; 04-02-2013 at 08:49 AM. Click to view previous post history.

  2. #2

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    Some lenses have elements that are cemented together. When the cement fails and a gap opens between the cemented elements we say the lens has a separation.

    Separation often manifests as Newton's rings (if you don't know what they are, Google will find an explanation), silvery spots in the lens, or as a "ring of fire."

    It is an especially bad problem with Rodenstock and Voigtlaender lenses made from the late 1950s to the mid-1970s. The synthetic cement both used after they stopped cementing lenses with Canada balsam was very prone to letting go of the glass.

  3. #3

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    Quote Originally Posted by Dan Fromm View Post
    Some lenses have elements that are cemented together. When the cement fails and a gap opens between the cemented elements we say the lens has a separation.

    Separation often manifests as Newton's rings (if you don't know what they are, Google will find an explanation), silvery spots in the lens, or as a "ring of fire."

    It is an especially bad problem with Rodenstock and Voigtlaender lenses made from the late 1950s to the mid-1970s. The synthetic cement both used after they stopped cementing lenses with Canada balsam was very prone to letting go of the glass.
    And I'll add to Dan's eplanation that sometimes, things such as fungus, dirt, and Schneideritus are called separation. Schneideritus is a lifting of the paint used to blacken the edges of the lens' elements, it appears as whitish spots or patches . It is not specific to S-K lenses, either; some Fuli lenses show it as well as other makes of lens. It's very easy to fix, and it effects the value much more than any other attribute.
    Dirt is, well, dirt. Fungus is another often misapplied term - you see and hear it very often it seems, but in all the decades I've been using lenses I've yet to have a lens afflicted with fungus. YMMV.

    Separation is not specific to vintage (whatever that term now means, it's so misused as to be meaningless) lenses, it can occur in lenses of any age. Old lenses cemented with balsam sometimes have it, but then they've had 100~ years for the balsam to go bad. Two common examples are Turner-Reich triple convertibles and Zeiss sreies VIIa convertibles.

  4. #4

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    You will see this in some of the Carl Zeiss lenses for the Zeiss Ikon Contax rangefinder, particularly the 50mm Sonnar (both f/1.5 and f/2.0).

  5. #5

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    I have a Rolleiflex 2.8F (Planar lens) with separation that's intruded into the lens maybe 3-4cm in places. I cannot tell you that I notice any degradation of the image, but of course it's something to monitor. I suppose it exhibits itself in increased flare (which I have not noticed with mine), but I am not sure how else the image would be affected.

  6. #6

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    Thanks for the clarafication.

    ToddB

  7. #7
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    There's some separation on the Tessar 45 on my ZI Contaflex II. Mr. Jon Goodman who frequently makes wry (and quite funny) comments on these forums, and who used to repair Contaflexes et. al, said that lens-separation is pretty common among these models. Mine shows it just around the edges. I have not noticed any effect so far, even shooting in full sun (though not INTO the sun — I'm conscious of the separation but not overly careful). The lens is still a firecracker, despite its elements' marital problems.

    Click image for larger version. 

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    Here's an example from a roll of Ektar, processed by Walgreens.
    Click image for larger version. 

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  8. #8
    IloveTLRs's Avatar
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    I had two Carl Zeiss lenses with separation: a Sonnar 50/1.5 in Contax rangefinder mount and a 150/4 for the Hasselblad. The separation was very bad: distinct "rainbows" that started at the lens outside and ended half-way towards the middle. Dealers and friends alike asked me why on earth would I use such lenses. I emailed a photo of the Sonnar 50/1.5 to Henry Scherer who said something like it was one of the worst cases of separation he'd seen.

    However both performed fantastically, in black and white and color, pointed into the sun or away from it. I never noticed any effects at all. People couldn't believe it. I suppose Your Mileage May Vary.
    Those who know, shoot film

  9. #9

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    Here's a picture of an old Kodak Special Tessar type lens with what I believe is separation:
    Attached Thumbnails Attached Thumbnails KodakSpecial2.jpg  

  10. #10

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    Whether separations make a difference for anything but price depends on the separation.

    I have a 58/5.6 Rodenstock Grandagon with baad separations. Spectacular rings of fire, silvery spots, ... Looks like hell, shoots well.

    Years ago I bought a 16/2.5 Zeiss Luminar. There was balsam puddled around the periphery of the front glass, examination with a magnifier found voids (bubbles) between the cemented pair. The lens had much lower resolution and contrast than a good 16/2.5 Luminar borrowed from a friend. Much worse.

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