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    Re: Lunar Scopes
    From: Courtney Thomas
    Date: 2005 Feb 14, 09:47 -0500

    For those that might prefer a less expensive alternative to the SNO-T
    inverting scope,... my SNO-M inverting scope has all the same
    adjustments as my SNO-T inverting scope.
    Alexandre Eremenko wrote:
    > Frank,
    > 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:-)
    > Alex.
    s/v Mutiny
    Rhodes Bounty II
    lying Oriental, NC

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