Lens sample variation article. Different (i.e., "Chinese")contractors = different results

Discussion in 'Digital Photography' started by RichA, Nov 27, 2011.

  1. RichA

    RichA Guest

    So during the transition period for example Panasonic a couple years
    back, I wonder if anything changed when they shifted production of
    cameras from Japan to China?

    http://www.dpreview.com/articles/7333489584/variation-facts-and-fallacies

    However, I doubt the reason below from the article matters too much.
    Camera lenses are simply not used at high enough
    "magnifications" (though high pixel counts could be altering that) for
    five 9's versus six 9's precision in melt data to matter.

    Did you know that every time a glass manufacturer makes a run of a
    given optical glass, the refraction index and dispersion vary a tiny
    bit? The glass manufacturer furnishes a melt sheet to the lens
    manufacturer so they can make tiny adjustments in thickness or
    curvature of that element to compensate for the differences.

    The glass is probably a tiny source of variation compared to the other
    components that make up a lens or camera. In addition to the multiple
    glass elements, there are clips, shims, and grips that hold them in
    place within the lens. There are helicoids, barrels, gears, and rings
    move them around to focus. Electrical motors and circuit boards tell
    them what to do, and, as Chambers has shown us, even the lens mount
    that connects the lens to the camera is a source of variation.
     
    RichA, Nov 27, 2011
    #1
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  2. RichA

    PeterN Guest

    Re: Lens sample variation article. Different (i.e., "Chinese") contractors= different results

    On 11/27/2011 6:34 PM, RichA wrote:
    > So during the transition period for example Panasonic a couple years
    > back, I wonder if anything changed when they shifted production of
    > cameras from Japan to China?
    >
    > http://www.dpreview.com/articles/7333489584/variation-facts-and-fallacies
    >
    > However, I doubt the reason below from the article matters too much.
    > Camera lenses are simply not used at high enough
    > "magnifications" (though high pixel counts could be altering that) for
    > five 9's versus six 9's precision in melt data to matter.
    >
    > Did you know that every time a glass manufacturer makes a run of a
    > given optical glass, the refraction index and dispersion vary a tiny
    > bit? The glass manufacturer furnishes a melt sheet to the lens
    > manufacturer so they can make tiny adjustments in thickness or
    > curvature of that element to compensate for the differences.
    >
    > The glass is probably a tiny source of variation compared to the other
    > components that make up a lens or camera. In addition to the multiple
    > glass elements, there are clips, shims, and grips that hold them in
    > place within the lens. There are helicoids, barrels, gears, and rings
    > move them around to focus. Electrical motors and circuit boards tell
    > them what to do, and, as Chambers has shown us, even the lens mount
    > that connects the lens to the camera is a source of variation.



    Your reiteration is not at all what the article said. The author also
    points out that sample variation issues have been going on since prior
    to 1970.
    Without trying he describes your interpretation as follows: "Trying to
    find exactly the sharpest copy of the sharpest lens is a fool’s errand:
    you’ll be looking for something that doesn’t exist."

    Again your bullshit prejudices are shown to be groundless.
    I would normally ask you to point out the reference to China, but have
    seen from your numerous failures to give a meaningful answer that such a
    question would be fruitless.
    --
    Peter
     
    PeterN, Nov 28, 2011
    #2
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  3. RichA

    RichA Guest

    Re: Lens sample variation article. Different (i.e., "Chinese")contractors = different results

    On Nov 27, 7:50 pm, PeterN <> wrote:

    > Your reiteration is not at all what the article said.  The author also
    > points out that sample variation issues have been going on since prior
    > to 1970.


    So what? Where did I say that a lens's origin in China was the be-all
    and end-all of performance? Most lenses back then were poor back then
    (compared to now) unless from the very best companies. No cheap ED
    glass, no cheap molded aspherics.

    > Without trying he describes your interpretation as follows: "Trying to
    > find exactly the sharpest copy of the sharpest lens is a fool’s errand:
    > you’ll be looking for something that doesn’t exist."


    It's hardly impossible, only improbable. I've read of people who have
    purchased multiple copies of a lens to obtain the best one they can.
    This narrows down the odds. In addition, if tolerances are such that
    the top 40% of a lens are different but not so much to be
    indistinguishable from one another, then the odds are the person will
    have good luck finding a good sample.
    >
    > Again your bullshit prejudices are shown to be groundless.
    > I would normally ask you to point out the reference to China


    Do think they'd actually let him post something in an article on
    Dpreview that would reflect badly on a particular brand? Are you
    insane?
     
    RichA, Nov 28, 2011
    #3
  4. RichA

    PeterN Guest

    Re: Lens sample variation article. Different (i.e., "Chinese") contractors= different results

    On 11/27/2011 9:04 PM, RichA wrote:
    > On Nov 27, 7:50 pm, PeterN<> wrote:
    >
    >> Your reiteration is not at all what the article said. The author also
    >> points out that sample variation issues have been going on since prior
    >> to 1970.

    >
    > So what? Where did I say that a lens's origin in China was the be-all
    > and end-all of performance? Most lenses back then were poor back then
    > (compared to now) unless from the very best companies. No cheap ED
    > glass, no cheap molded aspherics.
    >
    >> Without trying he describes your interpretation as follows: "Trying to
    >> find exactly the sharpest copy of the sharpest lens is a fool’s errand:
    >> you’ll be looking for something that doesn’t exist."

    >
    > It's hardly impossible, only improbable. I've read of people who have
    > purchased multiple copies of a lens to obtain the best one they can.
    > This narrows down the odds. In addition, if tolerances are such that
    > the top 40% of a lens are different but not so much to be
    > indistinguishable from one another, then the odds are the person will
    > have good luck finding a good sample.
    >>
    >> Again your bullshit prejudices are shown to be groundless.
    >> I would normally ask you to point out the reference to China

    >
    > Do think they'd actually let him post something in an article on
    > Dpreview that would reflect badly on a particular brand? Are you
    > insane?


    Did you read your own title?

    --
    Peter
     
    PeterN, Nov 29, 2011
    #4
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