NavList:

Bill,

> My left eye distorts a sphere, with the vertical axis longer than the
> horizontal axis.  My right eye distorts a sphere with the vertical axis
> shorter than the horizontal axis.

In theory, this should be irrelevant for observations, if you see
all edges sharp.
I would rather attribute the difference between sextant
horizontal and sextant vertical to sextant non-rigidity.

Test: use your sextant upside down.

> NOTE:  All sun IE checks were made without changing focus, as this will
> change IE and side error with my scope.

I would definitely change the focus.
And adjust the focus in the best possible way, for each eye.
Theoretically, IC cannot depend on changing the focus.

> Are there some other tests the list might propose?

Sextant upside down, as once proposed by George.
This is an excellent way to check your sextant non-rigidity,
and to convince you that the reason is not in your eyes.

> problem and possible problems with shades (shades on sun but often not on
> the horizon)

If you are willing to mess with the screws on your
sextant, one standard way is to reverse a shade.
(Another very good way is to use the eyepiece shade
for the index correction from Sun. You are welcome to use
my eyepiece shade, with your telescope, if it fits, or with
my telescope).

There is one more experiment: ask some younger friend
with perfect eyes to check your index correction.
It is easy to explain to anyone, how to do this.

Alex.


--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---