| |
[index]
[month]
[prev]
[next]
Subject: [M]: Goto accuracy question.
From: Paul Luckas
Reply To: mapug@shore.net
Date: Thu Jul 05 21:16:05 2001
|
While you're here, how about checking out the
Astronomy Book
List ? |
This is a multi-part message in MIME format.
------=_NextPart_000_0082_01C10615.6E3213A0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Greetings,
I've been following some of the recent posts on improving goto accuracy. =
While I'm not unhappy (objects are always within a 26mm eyepiece and =
generally end up centred when using "high precision" mode) I'm conscious =
that for CCD work I might need greater accuracy.
Backlash in RA is non-existent, and Dec minimal. I'm using a screw / =
spring arrangement to minimise mirror flop, a 9mm illuminated reticle =
eyepiece for star alignment centring, have fine tuned my time to the =
nearest couple of seconds, my lat/long to the nearest minute, and my =
levelling is very good to excellent. When aligning I always do final =
centring with the N and W keys.=20
Regardless of how much care I take, I still have objects off-centre in =
the 26mm -and usually off to the same side (bottom left in the field of =
view). Slewing back to the alignment stars puts them dead centre. All =
other objects seem to be at the edge of the 26mm. Am I being too fussy, =
or would a tweak of the OTA be in order (orthogonality - wise) ? Or, is =
there something else I've missed given the repeatability of error.
Would appreciate any thoughts.
------=_NextPart_000_0082_01C10615.6E3213A0
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=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 5.50.4616.200" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2>Greetings,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>I've been following some of the recent =
posts on=20
improving goto accuracy. While I'm not unhappy (objects are always =
within a 26mm=20
eyepiece and generally end up centred when using "high precision" mode) =
I'm=20
conscious that for CCD work I might need greater accuracy.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Backlash in RA is non-existent, and Dec =
minimal.=20
I'm using a screw / spring arrangement to minimise mirror flop, a =
9mm=20
illuminated reticle eyepiece for star alignment centring, have fine =
tuned my=20
time to the nearest couple of seconds, my lat/long to the nearest =
minute, and my=20
levelling is very good to excellent. When aligning I always do final =
centring=20
with the N and W keys. </FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Regardless of how much care I take, I =
still have=20
objects off-centre in the 26mm -and usually off to the same side (bottom =
left in=20
the field of view). Slewing back to the alignment stars puts them dead =
centre.=20
All other objects seem to be at the edge of the 26mm. Am I being too =
fussy, or=20
would a tweak of the OTA be in order (orthogonality - wise) ? Or, =
is there=20
something else I've missed given the repeatability of =
error.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Would appreciate any=20
thoughts.</FONT></DIV></BODY></HTML>
------=_NextPart_000_0082_01C10615.6E3213A0--
View index by [date] [author] [subject]
Previous message: Re: [M]: Need Hard Case for LX200 8" ASAP, RonK
Next message: Re: [M]: Re: RE: Need Hard Case for LX200 8" ASAP, Email address hidden
|
|