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Re: [Microscope] Re: vickers objectives

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  • goat
    Howdy, Thanks for the explanation and instruction. These are the ones that I bought. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2550926861 I guess I
    Message 1 of 20 , Aug 31, 2003
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      Howdy,
      Thanks for the explanation and instruction.
      These are the ones that I bought.
      http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2550926861
      I guess I will give them a try on the olympus model e,
      which I think does seem to have the necessary fine adjustments.
      For $35 total, it is worth a try (and could be fun!). I have them in
      hand, and they seem to be clear.
      I take it that Vickers definition of a microplan is
      the same as swift's (i.e. semi plan), or is it something different?
      The apoplan seems to be a non oil objective. Is this a correct
      assumption? Also, did these objectives require anything exotic
      for oculars?
      Thanks again,
      Goat

      mervhob wrote:
      > -Hi Goat,
      >
      > By centering, we mean the alignment of all the elements in the
      > optical train on exactly the same axis. This includes lamp, lamp
      > condenser and Kohler iris, microscope condenser, and aperture iris,
      > objective, and eyepieces. With the complexity of modern compound
      > microscopes, that can be a lot of glass surfaces to centre, but if it
      > is done religiously, the difference in performance can be startling.
      > In most cases of poor reported performance, centering will be found
      > at the root of the problems, other than those caused by dirty optics.
      > Not only must the output of part of the optical train be centered,but
      > all the subelements centres of curvature must ideally lie on axis.
      > This is particularily true of Plan, or PlanAPO objectives, where the
      > designer has used many elements, often of deep curvature, over a
      > considerable length. The Vickers Plan objectives tend to have very
      > small back elements, of very deep curvature. If a plan objective is
      > off-center, performance falls of rapidly, in particular, you cannot
      > open up the aperture iris on the condenser without flare occuring
      > much earlier than 2/3 max aperture. Fortunately, the Vickers M41 has
      > very good centering at all parts of the optical train, in the form of
      > Allen headed set screws. Centering is carried out by removing the
      > eyepieces, and using either a phase telescope, Bertrand lens, or a
      > cheap pair of high diopter plastic specs to observe the back focal
      > plane of the objective. Using the aperture of the back elements as
      > reference, all other parts are centred to this ring. Iris centring is
      > easy, and is checked by opening and closing the iris, checking the
      > intersection with the back focal plane. Axis centring of the elements
      > is more subtle, and depends on observing the scattered light at each
      > surface through a train of elements with a very small aperture, then
      > observing how the light distribution changes as the aperture is
      > opened and closed. When it is symmetrical, with no apparent change in
      > axis with aperture, everything is 'on line'and you should be able to
      > open up the working aperture to 3/4 aperture with no more disturbance
      > than on a simple monocular with ordinary achromats. Most good
      > microscopes have centering capability, and it is essential to getting
      > the best out of phase contrast and darkfield.
      >
      > Cheers,
      >
    • rvanwezel
      They seem like good objectives, and defenitely good value for money. The lower powers will do ok with probably most oculars; the high power will likely need a
      Message 2 of 20 , Sep 1, 2003
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        They seem like good objectives, and defenitely good value for money.
        The lower powers will do ok with probably most oculars; the high
        power will likely need a compensation ocular, recognisable on the
        yellow fringe on the border of the image. In absense of thet, the
        objects will show colour shifts on the edges, but in the middle of
        field it should still be usable. Mind you, this 63/0.95 is very
        sensitive to changes in slide thickness, you might find it's not as
        usefull as you think.

        Good luck
        Rene.


        --- In Microscope@yahoogroups.com, goat <goatmoag@a...> wrote:
        > Howdy,
        > Thanks for the explanation and instruction.
        > These are the ones that I bought.
        > http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2550926861
        > I guess I will give them a try on the olympus model e,
        > which I think does seem to have the necessary fine adjustments.
        > For $35 total, it is worth a try (and could be fun!). I have them in
        > hand, and they seem to be clear.
        > I take it that Vickers definition of a microplan is
        > the same as swift's (i.e. semi plan), or is it something different?
        > The apoplan seems to be a non oil objective. Is this a correct
        > assumption? Also, did these objectives require anything exotic
        > for oculars?
        > Thanks again,
        > Goat
      • mervhob
        Goat, Had a look at the pics on ebay, you have done very well! The x63 APOplan is a wonderful piece of glass, and is a high dry, hence the NA 0.95, the maximum
        Message 3 of 20 , Sep 1, 2003
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          Goat,

          Had a look at the pics on ebay, you have done very well! The x63
          APOplan is a wonderful piece of glass, and is a high dry, hence the
          NA 0.95, the maximum feasible in air. However, are you sure it is a
          biological objective? Most of the Vickers APOplans were metallurgical
          and were designed for use on uncovered objects - no coverglass. It
          should state on the body of the objectives either 160/0.18 or Met.
          If it is a biological APOplan, then you have done very, very well!

          Cheers,

          Merv

          --- In Microscope@yahoogroups.com, goat <goatmoag@a...> wrote:
          > Howdy,
          > Thanks for the explanation and instruction.
          > These are the ones that I bought.
          > http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2550926861
          > I guess I will give them a try on the olympus model e,
          > which I think does seem to have the necessary fine adjustments.
          > For $35 total, it is worth a try (and could be fun!). I have them in
          > hand, and they seem to be clear.
          > I take it that Vickers definition of a microplan is
          > the same as swift's (i.e. semi plan), or is it something different?
          > The apoplan seems to be a non oil objective. Is this a correct
          > assumption? Also, did these objectives require anything exotic
          > for oculars?
          > Thanks again,
          > Goat
          >
          > mervhob wrote:
          > > -Hi Goat,
          > >
          > > By centering, we mean the alignment of all the elements in the
          > > optical train on exactly the same axis. This includes lamp, lamp
          > > condenser and Kohler iris, microscope condenser, and aperture
          iris,
          > > objective, and eyepieces. With the complexity of modern compound
          > > microscopes, that can be a lot of glass surfaces to centre, but
          if it
          > > is done religiously, the difference in performance can be
          startling.
          > > In most cases of poor reported performance, centering will be
          found
          > > at the root of the problems, other than those caused by dirty
          optics.
          > > Not only must the output of part of the optical train be
          centered,but
          > > all the subelements centres of curvature must ideally lie on
          axis.
          > > This is particularily true of Plan, or PlanAPO objectives,
          where the
          > > designer has used many elements, often of deep curvature, over a
          > > considerable length. The Vickers Plan objectives tend to have
          very
          > > small back elements, of very deep curvature. If a plan
          objective is
          > > off-center, performance falls of rapidly, in particular, you
          cannot
          > > open up the aperture iris on the condenser without flare
          occuring
          > > much earlier than 2/3 max aperture. Fortunately, the Vickers
          M41 has
          > > very good centering at all parts of the optical train, in the
          form of
          > > Allen headed set screws. Centering is carried out by removing
          the
          > > eyepieces, and using either a phase telescope, Bertrand lens,
          or a
          > > cheap pair of high diopter plastic specs to observe the back
          focal
          > > plane of the objective. Using the aperture of the back elements
          as
          > > reference, all other parts are centred to this ring. Iris
          centring is
          > > easy, and is checked by opening and closing the iris, checking
          the
          > > intersection with the back focal plane. Axis centring of the
          elements
          > > is more subtle, and depends on observing the scattered light at
          each
          > > surface through a train of elements with a very small aperture,
          then
          > > observing how the light distribution changes as the aperture is
          > > opened and closed. When it is symmetrical, with no apparent
          change in
          > > axis with aperture, everything is 'on line'and you should be
          able to
          > > open up the working aperture to 3/4 aperture with no more
          disturbance
          > > than on a simple monocular with ordinary achromats. Most good
          > > microscopes have centering capability, and it is essential to
          getting
          > > the best out of phase contrast and darkfield.
          > >
          > > Cheers,
          > >
        • goat
          Howdy Merv, You are right, they are are Met. (at least the 20 and the 63). I was wondering why they didn t have a cover glass thickness on them. The .95 na was
          Message 4 of 20 , Sep 1, 2003
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            Howdy Merv,
            You are right, they are are Met. (at least the 20 and the 63).
            I was wondering why they didn't have a cover glass thickness on them.
            The .95 na was indeed why assumed the 63x was an hd.
            Now I am wondering how useful it will be. : )
            Thanks,
            Goat!


            mervhob wrote:
            > Goat,
            >
            > Had a look at the pics on ebay, you have done very well! The x63
            > APOplan is a wonderful piece of glass, and is a high dry, hence the
            > NA 0.95, the maximum feasible in air. However, are you sure it is a
            > biological objective? Most of the Vickers APOplans were metallurgical
            > and were designed for use on uncovered objects - no coverglass. It
            > should state on the body of the objectives either 160/0.18 or Met.
            > If it is a biological APOplan, then you have done very, very well!
            >
            > Cheers,
            >
            > Merv
          • mervhob
            Howdy Goat, Well, I had a suspicion that would be the case as my friend Ted Brain informs me that no biological APOplans were ever made by Vickers. If you
            Message 5 of 20 , Sep 3, 2003
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              Howdy Goat,
              Well, I had a suspicion that would be the case as my friend Ted Brain
              informs me that no biological APOplans were ever made by Vickers. If
              you can't think of a use for the x20 and the x63, as most of the work
              I do involves incident illumination, I would be happy to give you a
              good price for them, or, horse trade for some good biological
              objectives. Tell me what you need,or what sort of materials you are
              interested in, and I will see what I can do.

              Cheers,

              Merv
              -- In Microscope@yahoogroups.com, goat <goatmoag@a...> wrote:
              > Howdy Merv,
              > You are right, they are are Met. (at least the 20 and the 63).
              > I was wondering why they didn't have a cover glass thickness on
              them.
              > The .95 na was indeed why assumed the 63x was an hd.
              > Now I am wondering how useful it will be. : )
              > Thanks,
              > Goat!
              >
              >
              > mervhob wrote:
              > > Goat,
              > >
              > > Had a look at the pics on ebay, you have done very well! The x63
              > > APOplan is a wonderful piece of glass, and is a high dry, hence
              the
              > > NA 0.95, the maximum feasible in air. However, are you sure it is
              a
              > > biological objective? Most of the Vickers APOplans were
              metallurgical
              > > and were designed for use on uncovered objects - no coverglass.
              It
              > > should state on the body of the objectives either 160/0.18 or Met.
              > > If it is a biological APOplan, then you have done very, very
              well!
              > >
              > > Cheers,
              > >
              > > Merv
            • goat!
              ... Hiya Merv, I also got the impression that there was no apoplans for the Vickers on one (and just about only) site that I could find about them. I d be
              Message 6 of 20 , Sep 8, 2003
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                mervhob wrote:
                > Howdy Goat,
                > Well, I had a suspicion that would be the case as my friend Ted Brain
                > informs me that no biological APOplans were ever made by Vickers. If
                > you can't think of a use for the x20 and the x63, as most of the work
                > I do involves incident illumination, I would be happy to give you a
                > good price for them, or, horse trade for some good biological
                > objectives. Tell me what you need,or what sort of materials you are
                > interested in, and I will see what I can do.
                >

                Hiya Merv,
                I also got the impression that there was no apoplans for the Vickers
                on one (and just about only) site that I could find about them.
                I'd be happy to trade them for something comparable in
                biological lenses, failing that, make me an offer I can't refuse. : )
                Thanks,

                --
                Goat!
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