| |
[index]
[month]
[prev]
[next]
[thead-prev]
[thread-next]
Subject: [M]: Re: Polar alignment and collimation
From: Blair MacDonald
Reply To: mapug@shore.net
Date: Sun Feb 18 08:36:05 2001
|
While you're here, how about checking out the
Astronomy Book
List ? |
This is a multi-part message in MIME format.
------=_NextPart_000_00A6_01C0999E.FA7618E0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Collimation will not affect polar alignment. Polar alignment is the =
process of pointing the Dec axis of the mount at the pole. Collimation =
will however change the relationship of the optical axis to the mount =
and thus may change your pointing accuracy. Assuming that Meade got it =
right when the scope left the factory then it should not cause you any =
problem.=20
As for the colour fringing, I'm not sure. I certainly don't see any sign =
of it in my Schmidt Newtonian. You may be seeing an artifact of your =
eyepiece. Try another eyepiece and see if the problem changes.
Blair
----- Original Message -----=20
From: Dr. Michael Blaber=20
Sent: Sunday, February 18, 2001 10:45 AM
Subject: [M]: Polar alignment and collimation
Greetings
I have a questions about effects of collimation upon alignment of the =
telescope. I just spent several hours getting a precise polar =
alignment. My next goal was to collimate the scope (LX-200). However, =
I had a horrible thought that if I adjusted the secondary mirror, the =
polar alignment would be compromised. I suspect the best order is to =
collimate first, then align. I have tried to think through this, and =
believe that collimation will not actually affect the alignment, but am =
not 100% sure of this. Does anyone know for sure? =20
Also, with regard to collimation of the LX-200: on bright stars I can =
see some color aberation (red cusp on one side of a star, blue on the =
other). How much of this is unavoidable. In other words, would this =
disappear with accurate collimation, or is some aberation just a fact of =
life with this type of scope?
Thank you
Mike Blaber
------=_NextPart_000_00A6_01C0999E.FA7618E0
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type =
content=3Dtext/html;charset=3Diso-8859-1>
<META content=3D"MSHTML 5.50.4611.1300" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2>Collimation will not affect polar =
alignment. Polar=20
alignment is the process of pointing the Dec axis of the mount at the =
pole.=20
Collimation will however change the relationship of the optical axis to =
the=20
mount and thus may change your pointing accuracy. Assuming that Meade =
got it=20
right when the scope left the factory then it should not cause you any =
problem.=20
</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>As for the colour fringing, I'm not =
sure. I=20
certainly don't see any sign of it in my Schmidt Newtonian. You may be =
seeing an=20
artifact of your eyepiece. Try another eyepiece and see if the problem=20
changes.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Blair</FONT></DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
Michael=20
Blaber</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Sunday, February 18, 2001 =
10:45=20
AM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> [M]: Polar alignment =
and=20
collimation</DIV>
<DIV><BR></DIV>
<DIV><FONT face=3DArial size=3D2>Greetings</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>I have a questions about effects of =
collimation=20
upon alignment of the telescope. I just spent several hours =
getting a=20
precise polar alignment. My next goal was to collimate the scope =
(LX-200). However, I had a horrible thought that if I adjusted =
the=20
secondary mirror, the polar alignment would be compromised. I =
suspect=20
the best order is to collimate first, then align. I have tried =
to think=20
through this, and believe that collimation will not actually affect =
the=20
alignment, but am not 100% sure of this. Does anyone know for=20
sure? </FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Also, with regard to collimation of =
the=20
LX-200: on bright stars I can see some color aberation (red cusp =
on one=20
side of a star, blue on the other). How much of this is=20
unavoidable. In other words, would this disappear with accurate=20
collimation, or is some aberation just a fact of life with this type =
of=20
scope?</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Thank you</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Mike =
Blaber</FONT></DIV></BLOCKQUOTE></BODY></HTML>
------=_NextPart_000_00A6_01C0999E.FA7618E0--
View index by [date] [author] [subject]
Previous message: Re: [M]: Lx200 demo party, amnet_ed
Next message: Re: [M]: Polar alignment and collimation, Ralph P. Pass III
Next message in thread: Re: [M]: Polar alignment and collimation, Ralph P. Pass III
Previous message in thread: [M]: Polar alignment and collimation, Dr. Michael Blaber
|
|