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    Re: Lunar Scopes
    From: Courtney Thomas
    Date: 2005 Feb 14, 11:32 -0500

    You misconstrue my meaning  :-)
    I'm not suggesting anyone buy anything,.. rather merely pointing out
    that if someone wanted a sextant with an adjustable lunar scope the
    CHO-M is cheaper than the CHO-T.
    Further, the CHO-M lunar scope is not exactly the same as the CHO-T
    lunar scope, at least as far as the two I have.
    As to whether optically they are equivalent, I don't know, but
    mechanically they are dissimilar. Moreover, whether their physical
    differences matter to a user, I also don't know.
    I understand they were both used by the Soviet Navy so I assume they are
    both of adequate capability for a yachtsman  :-)
    Alexandre Eremenko wrote:
    > Courtney,
    > As I can judge from the pictures,
    > and from SNO-M manual, it is just the SAME scope.
    > So you are proposing buying an SNO-M just for its
    > scope? Well, the current advertised price
    > in maurnavy.com/ is $145, plus $80 (at least)
    > for shipping and money transfer... A bit too expensive
    > for an old used scope in unknown condition.
    > Alex.
    > On Mon, 14 Feb 2005, Courtney Thomas wrote:
    >>For those that might prefer a less expensive alternative to the CHO-T
    >>inverting scope,... my CHO-M inverting scope has all the same
    >>adjustments as my CHO-T inverting scope.
    >>Alexandre Eremenko wrote:
    >>>We already discussed these SNO inverting scopes
    >>>a lot on this list, so let me try to summarize:
    >>>On Sun, 13 Feb 2005, Frank Reed wrote:
    >>>>If I have it right then, the feature that you
    >>>>like about the inverting
    >>>>scopes is not that they're inverting
    >>>>but he fact that they have adjustable
    >>>>alignment (which would make good sense). Yes?
    >>>That it is inverting is not a "feature":-)
    >>>It is just an accidental property, irrelevant
    >>>for astronomical observations. But relevant in binoculars,
    >>>designed for looking at objects on the earth,
    >>>that's why they never make inverting binoculars.
    >>>But from the pure optical point of view, Kepler scopes are
    >>>superior to everything else.
    >>>The features are:
    >>>1. They let maximal amount of light through.
    >>>Because they have the
    >>>minimal possible number of lenses (2) and no prisms or mirrors.
    >>>Probably this is the main advantage. This is also the
    >>>reason astonomers prefer them.
    >>>2. They have no prisms and thus are much smaller and
    >>>lighter than comparable prismatic scopes.
    >>>3. At the same time they have larger field of view
    >>>in comparison with Galileo scopes of equal diameter
    >>>and magnification.
    >>>4. They have wires (you cannot mount wires in a Galileo scope).
    >>>The usefulness of wires was discussed a lot on the list,
    >>>so I do not repeat the arguments. I remember that Frank
    >>>was not convinced in their usefulness.
    >>>5. They have collimation adjustment.
    >>>I don't know why most modern sextants do not have it,
    >>>maybe because for this adjustment you need wires, and it is
    >>>impossible to put wires in a Galileo scope:-)
    >>s/v Mutiny
    >>Rhodes Bounty II
    >>lying Oriental, NC
    s/v Mutiny
    Rhodes Bounty II
    lying Oriental, NC

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