|
We had a clear night tonight, with no wind or moon.? So out I went again. ? After polar aligning with Polemaster (probably not necessary, since the tripod hadn¡¯t moved, but good practice), I turned off the hand controller, put it in CWD position, then did a cold start.? ? I told it to go to Altair (east side); it wasn¡¯t on the finder scope, but it wasn¡¯t too bad.? I centered, and clicked Menu>Align>Alignment.? I then told it to go to Deneb.? It wasn¡¯t far off center on the illuminated reticle eyepiece; I centered, and clicked Menu>Align>Alignment.? I told it to go to Vega, and repeated the process (it was very close to center).? Finally, I did Alberio (I like Alberio, so I¡¯ll use any excuse to look at it).? It also was close to centered. ? Going to the west side, I told it to go to Mizar.? It was not very close (not on the finder, but it was on the Telrad).? I centered, clicked Menu>Align>Alignment.? And declared victory for the modeling. ? I substituted a 26mm Nagler Type 5 as my eyepiece, and told it to go to M27 (east side).? It was pretty well centered.? Repeated for a number of east side targets, all with good success.? Told it to go to M81 (west side); it wasn¡¯t so well centered, but it was on the eyepiece.? Told it to go to M31 (east side); it was at the very edge of the field of the 26mm Nagler.? Told it to go to M57, and it was reasonably well centered. ? I think that this probably is as good as it gets.? I¡¯ve heard all the people saying that I¡¯m too optimistic expecting everything to be centered, so I¡¯ll accept the imperfections.? It¡¯s good enough for my limited needs. ? I thank everyone for their help, particularly Brian Valente. ? I wish everyone clear skies, and a good night. ? Mark de REgt ?
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From: [email protected] < [email protected]> On Behalf Of Mark de Regt via groups.io Sent: Wednesday, August 17, 2022 8:58 AM To: [email protected]Subject: [Losmandy_users_io] Usability Question--Update ? I went through all of the suggestions made, and collected those that seemed might possibly be connected to my problem.? Then I implemented them. ? Last night was a test. ? I carefully determined the CWD position. ?Although, to be honest, there is absolutely no way I know of to know when the counterweight bar really is pointing as down as it can, since a bubble level depends on catching exactly the right part of the curve, and not moving it at all.? But I also understand that that matters only for the first slew. ? I slowed the speed at which the mount slews, to lessen the probability that anything skips with the sudden torque. ? I did a careful polar alignment with PoleMaster. ? I made sure that time, date, and place were all very accurate. ? I deleted any existing model. ? I sent the mount to Altair.? It missed by a fair amount.? I decided that maybe I should only ¡°center¡± using ¡°center¡± or ¡°guide,¡± not ¡°move¡± or ¡°slew,¡± so it took a while to center Altair.? After carefully centering Altair on my illuminated-crosshair eyepiece, I selected ¡°Menu,¡± then ¡°Align,¡± then ¡°synchronize.¡± ? I told it to go to Vega.? It was almost perfectly centered.? I centered, synced, then told it to go to Deneb. ? It was perfectly centered. ? The west side of my sky is pretty much destroyed with Seattle sky glow and trees.? So I decided to play on the east side, to see how it worked,?
It worked very well!? Everything I told it to go to was reasonably well centered. ? Then I told it to go to Mizar, very much on the west side, but easy to see. ? It missed by a lot.? I centered it, and synced. ? I told it to go back to Deneb.? It was on the eyepiece (17mm Nagler Type 4, on a Celestron 11¡± EdgeHD), but quite far off center.? I centered and synced.? Told it to go to M27.? It was centered pretty well,? I told it to go back to Mizar, and it barely was on the eyepiece. ? And so the night went.? I found no way to get it to converge on a model that got everything reasonably close to the center of the eyepiece (I wouldn¡¯t care so much, except that it¡¯s a royal PITA to center anything, to me, on a GEM, since I have no idea which of the four buttons to hit at any time to get it to move in any particular direction). ? It was somewhat promising, in that it always got the target on the (very, very wide) eyepiece, but it is far, far from perfect. ? Mark
|
Very good, Mark,...that you got back to useability.??
There can be also good value to dig into why the pointing may be imperfect, if you now, having built a Model using your Gemini:
Look at the model parameters, which the Gemini calculated.? The largest values are going to tell you the largest "errors" from a perfectly polar aligned, zero cone angle, zero counterweight shaft bending perfect telescope and perfect mount.
If you were to boot up your Gemini using Warm.Boot, this reads back into the active memory the last set of Model parameters that were stored in the Gemini long term memory.?
(If you Cold Boot, you erase all those Model parameters back to all zeros...so don't Cold Boot until you write down the prior calculated values on paper!.)
Connect your Gemini to a PC, and use the ASCOM Gemini.net applet, go to its Advanced panel, press the bottom right area "From Gemini" (to the PC that is) and look for the "rolled up" section "Model parameters".??
Write down those numbers. If they are all zero, then your Model data is erased...that happens if you press "Cold Boot" when you boot up your Gemini unit.
These are the factors that Rene Goerlich designed into the Gemini mount modeling software.? They are a key to understanding if your polar alignment is off, if you have cone angle in your dovetail mounting, etc.??
A nice description of these error factors is in the Gemini-1 user manual, on which the Gemini-2 was also built.??
Mark.Crossley also has a description of these Model factors known his very useful website ?
Mark gives good information about the AZimuth and Elevation errors in the Gemini model of its polar alignment corrections:
Page 39 of the Gemini1 manual, which you can download, lists the factors shown in the photo attached.??
Ideally you want these values near zero.? See what story your values tell you about your mount system.
One more thing...if you make a model, then you adjust the mount...say you raise the Elevation or rotate the AZimuth, then the model is no longer correct.? You should then park at CWD and reboot with a Cold Boot.
And if your Gemini.net has its checkboxes to "reload model at connect" then your PC can overwrite the model you may have made with just the handset.? These checkboxes can be handy and useful, or cause you trouble.? Be careful with them.??
Best regards, Michael
On Mon, Aug 22, 2022, 10:47 PM Mark de Regt < deregt@...> wrote: We had a clear night tonight, with no wind or moon.? So out I went again. ? After polar aligning with Polemaster (probably not necessary, since the tripod hadn¡¯t moved, but good practice), I turned off the hand controller, put it in CWD position, then did a cold start.? ? I told it to go to Altair (east side); it wasn¡¯t on the finder scope, but it wasn¡¯t too bad.? I centered, and clicked Menu>Align>Alignment.? I then told it to go to Deneb.? It wasn¡¯t far off center on the illuminated reticle eyepiece; I centered, and clicked Menu>Align>Alignment.? I told it to go to Vega, and repeated the process (it was very close to center).? Finally, I did Alberio (I like Alberio, so I¡¯ll use any excuse to look at it).? It also was close to centered. ? Going to the west side, I told it to go to Mizar.? It was not very close (not on the finder, but it was on the Telrad).? I centered, clicked Menu>Align>Alignment.? And declared victory for the modeling. ? I substituted a 26mm Nagler Type 5 as my eyepiece, and told it to go to M27 (east side).? It was pretty well centered.? Repeated for a number of east side targets, all with good success.? Told it to go to M81 (west side); it wasn¡¯t so well centered, but it was on the eyepiece.? Told it to go to M31 (east side); it was at the very edge of the field of the 26mm Nagler.? Told it to go to M57, and it was reasonably well centered. ? I think that this probably is as good as it gets.? I¡¯ve heard all the people saying that I¡¯m too optimistic expecting everything to be centered, so I¡¯ll accept the imperfections.? It¡¯s good enough for my limited needs. ? I thank everyone for their help, particularly Brian Valente. ? I wish everyone clear skies, and a good night. ? Mark de REgt ? ? I went through all of the suggestions made, and collected those that seemed might possibly be connected to my problem.? Then I implemented them. ? Last night was a test. ? I carefully determined the CWD position.? Although, to be honest, there is absolutely no way I know of to know when the counterweight bar really is pointing as down as it can, since a bubble level depends on catching exactly the right part of the curve, and not moving it at all.? But I also understand that that matters only for the first slew. ? I slowed the speed at which the mount slews, to lessen the probability that anything skips with the sudden torque. ? I did a careful polar alignment with PoleMaster. ? I made sure that time, date, and place were all very accurate. ? I deleted any existing model. ? I sent the mount to Altair.? It missed by a fair amount.? I decided that maybe I should only ¡°center¡± using ¡°center¡± or ¡°guide,¡± not ¡°move¡± or ¡°slew,¡± so it took a while to center Altair.? After carefully centering Altair on my illuminated-crosshair eyepiece, I selected ¡°Menu,¡± then ¡°Align,¡± then ¡°synchronize.¡± ? I told it to go to Vega.? It was almost perfectly centered.? I centered, synced, then told it to go to Deneb. ? It was perfectly centered. ? The west side of my sky is pretty much destroyed with Seattle sky glow and trees.? So I decided to play on the east side, to see how it worked,?
It worked very well!? Everything I told it to go to was reasonably well centered. ? Then I told it to go to Mizar, very much on the west side, but easy to see. ? It missed by a lot.? I centered it, and synced. ? I told it to go back to Deneb.? It was on the eyepiece (17mm Nagler Type 4, on a Celestron 11¡± EdgeHD), but quite far off center.? I centered and synced.? Told it to go to M27.? It was centered pretty well,? I told it to go back to Mizar, and it barely was on the eyepiece. ? And so the night went.? I found no way to get it to converge on a model that got everything reasonably close to the center of the eyepiece (I wouldn¡¯t care so much, except that it¡¯s a royal PITA to center anything, to me, on a GEM, since I have no idea which of the four buttons to hit at any time to get it to move in any particular direction). ? It was somewhat promising, in that it always got the target on the (very, very wide) eyepiece, but it is far, far from perfect. ? Mark
|
Hi Mark,
Sounds like you're making progress! The thing about Gemini model is that it can take into account additional variables, like axis non-perpendicularity or even mirror flop, if you add a few more stars to the model. 5-8 stars might be enough to help center the object even better, but it is a tradeoff in time it takes to get started vs. time you spend later trying to find/center the objects. Your decision, ultimately, but you may want to at least try more than three stars, to see if it helps.
Regards,
? ?-Paul
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On Tue, Aug 23, 2022 at 01:47 AM, Mark de Regt wrote:
We had a clear night tonight, with no wind or moon.? So out I went again.
?
After polar aligning with Polemaster (probably not necessary, since the tripod hadn¡¯t moved, but good practice), I turned off the hand controller, put it in CWD position, then did a cold start.?
?
I told it to go to Altair (east side); it wasn¡¯t on the finder scope, but it wasn¡¯t too bad.? I centered, and clicked Menu>Align>Alignment.? I then told it to go to Deneb.? It wasn¡¯t far off center on the illuminated reticle eyepiece; I centered, and clicked Menu>Align>Alignment.? I told it to go to Vega, and repeated the process (it was very close to center).? Finally, I did Alberio (I like Alberio, so I¡¯ll use any excuse to look at it).? It also was close to centered.
?
Going to the west side, I told it to go to Mizar.? It was not very close (not on the finder, but it was on the Telrad).? I centered, clicked Menu>Align>Alignment.? And declared victory for the modeling.
?
I substituted a 26mm Nagler Type 5 as my eyepiece, and told it to go to M27 (east side).? It was pretty well centered.? Repeated for a number of east side targets, all with good success.? Told it to go to M81 (west side); it wasn¡¯t so well centered, but it was on the eyepiece.? Told it to go to M31 (east side); it was at the very edge of the field of the 26mm Nagler.? Told it to go to M57, and it was reasonably well centered.
?
I think that this probably is as good as it gets.? I¡¯ve heard all the people saying that I¡¯m too optimistic expecting everything to be centered, so I¡¯ll accept the imperfections.? It¡¯s good enough for my limited needs.
?
I thank everyone for their help, particularly Brian Valente.
?
I wish everyone clear skies, and a good night.
?
Mark de REgt
?
?
I went through all of the suggestions made, and collected those that seemed might possibly be connected to my problem.? Then I implemented them.
?
Last night was a test.
?
I carefully determined the CWD position. ?Although, to be honest, there is absolutely no way I know of to know when the counterweight bar really is pointing as down as it can, since a bubble level depends on catching exactly the right part of the curve, and not moving it at all.? But I also understand that that matters only for the first slew.
?
I slowed the speed at which the mount slews, to lessen the probability that anything skips with the sudden torque.
?
I did a careful polar alignment with PoleMaster.
?
I made sure that time, date, and place were all very accurate.
?
I deleted any existing model.
?
I sent the mount to Altair.? It missed by a fair amount.? I decided that maybe I should only ¡°center¡± using ¡°center¡± or ¡°guide,¡± not ¡°move¡± or ¡°slew,¡± so it took a while to center Altair.? After carefully centering Altair on my illuminated-crosshair eyepiece, I selected ¡°Menu,¡± then ¡°Align,¡± then ¡°synchronize.¡±
?
I told it to go to Vega.? It was almost perfectly centered.? I centered, synced, then told it to go to Deneb.
?
It was perfectly centered.
?
The west side of my sky is pretty much destroyed with Seattle sky glow and trees.? So I decided to play on the east side, to see how it worked,?
It worked very well!? Everything I told it to go to was reasonably well centered.
?
Then I told it to go to Mizar, very much on the west side, but easy to see.
?
It missed by a lot.? I centered it, and synced.
?
I told it to go back to Deneb.? It was on the eyepiece (17mm Nagler Type 4, on a Celestron 11¡± EdgeHD), but quite far off center.? I centered and synced.? Told it to go to M27.? It was centered pretty well,? I told it to go back to Mizar, and it barely was on the eyepiece.
?
And so the night went.? I found no way to get it to converge on a model that got everything reasonably close to the center of the eyepiece (I wouldn¡¯t care so much, except that it¡¯s a royal PITA to center anything, to me, on a GEM, since I have no idea which of the four buttons to hit at any time to get it to move in any particular direction).
?
It was somewhat promising, in that it always got the target on the (very, very wide) eyepiece, but it is far, far from perfect.
?
Mark
|
Going
to the west side, I told it to go to Mizar.? It was not very close (not on
the finder, but it was on the Telrad).? I centered, clicked
Menu>Align>Alignment.? And declared victory for the modeling.
***
Now
that you can do it, go back to the instructions or videos or whatever and build
a *better* model.. You put 4 stars into the East Model, but only one into the
West..
But..
YEAH! WOOO HOOO! :-))
Derek
?
?
?
We
had a clear night tonight, with no wind or moon.? So out I went again.
?
After
polar aligning with Polemaster (probably not necessary, since the tripod
hadn¡¯t moved, but good practice), I turned off the hand controller, put
it in CWD position, then did a cold start.?
?
I
told it to go to Altair (east side); it wasn¡¯t on the finder scope, but
it wasn¡¯t too bad.? I centered, and clicked
Menu>Align>Alignment.? I then told it to go to Deneb.? It
wasn¡¯t far off center on the illuminated reticle eyepiece; I centered,
and clicked Menu>Align>Alignment.? I told it to go to Vega, and repeated
the process (it was very close to center).? Finally, I did Alberio (I like
Alberio, so I¡¯ll use any excuse to look at it).? It also was close
to centered.
?
Going
to the west side, I told it to go to Mizar.? It was not very close (not on
the finder, but it was on the Telrad).? I centered, clicked
Menu>Align>Alignment.? And declared victory for the modeling.
?
I
substituted a 26mm Nagler Type 5 as my eyepiece, and told it to go to M27 (east
side).? It was pretty well centered.? Repeated for a number of east
side targets, all with good success.? Told it to go to M81 (west side); it
wasn¡¯t so well centered, but it was on the eyepiece.? Told it to go
to M31 (east side); it was at the very edge of the field of the 26mm
Nagler.? Told it to go to M57, and it was reasonably well centered.
?
I
think that this probably is as good as it gets.? I¡¯ve heard all the
people saying that I¡¯m too optimistic expecting everything to be
centered, so I¡¯ll accept the imperfections.? It¡¯s good enough
for my limited needs.
?
I
thank everyone for their help, particularly Brian Valente.
?
I
wish everyone clear skies, and a good night.
?
Mark
de REgt
?
toggle quoted message
Show quoted text
From: [email protected]
< [email protected]> On Behalf Of
Mark de Regt via groups.io
Sent: Wednesday, August 17, 2022
8:58 AM
To: [email protected]
Subject: [Losmandy_users_io]
Usability Question--Update
?
I
went through all of the suggestions made, and collected those that seemed might
possibly be connected to my problem.? Then I implemented them.
?
Last
night was a test.
?
I
carefully determined the CWD position. ?Although, to be honest, there is
absolutely no way I know of to know when the counterweight bar really is
pointing as down as it can, since a bubble level depends on catching exactly
the right part of the curve, and not moving it at all.? But I also
understand that that matters only for the first slew.
?
I
slowed the speed at which the mount slews, to lessen the probability that
anything skips with the sudden torque.
?
I
did a careful polar alignment with PoleMaster.
?
I
made sure that time, date, and place were all very accurate.
?
I
deleted any existing model.
?
I
sent the mount to Altair.? It missed by a fair amount.? I decided
that maybe I should only ¡°center¡± using ¡°center¡± or
¡°guide,¡± not ¡°move¡± or ¡°slew,¡± so it took a
while to center Altair.? After carefully centering Altair on my
illuminated-crosshair eyepiece, I selected ¡°Menu,¡± then
¡°Align,¡± then ¡°synchronize.¡±
?
I
told it to go to Vega.? It was almost perfectly centered.? I
centered, synced, then told it to go to Deneb.
?
It
was perfectly centered.
?
The
west side of my sky is pretty much destroyed with Seattle sky glow and trees.? So I
decided to play on the east side, to see how it worked,?
It worked very well!? Everything I told it to go to was reasonably well
centered.
?
Then
I told it to go to Mizar, very much on the west side, but easy to see.
?
It
missed by a lot.? I centered it, and synced.
?
I
told it to go back to Deneb.? It was on the eyepiece (17mm Nagler Type 4,
on a Celestron 11¡± EdgeHD), but quite far off center.? I centered
and synced.? Told it to go to M27.? It was centered pretty
well,? I told it to go back to Mizar, and it barely was on the eyepiece.
?
And
so the night went.? I found no way to get it to converge on a model that
got everything reasonably close to the center of the eyepiece (I wouldn¡¯t
care so much, except that it¡¯s a royal PITA to center anything, to me, on
a GEM, since I have no idea which of the four buttons to hit at any time to get
it to move in any particular direction).
?
It
was somewhat promising, in that it always got the target on the (very, very
wide) eyepiece, but it is far, far from perfect.
?
Mark
|
Also,
when you have good models for both sides, and you don¡¯t move the mount,
you can either reset CWD and use Warm Start, or just power up and use Warm
Restart.. Both use the model you made previously, saving startup time..
Derek
?
toggle quoted message
Show quoted text
From: [email protected]
[mailto:[email protected]] On Behalf
Of Derek C Breit
Sent: Tuesday, August 23, 2022
7:31 AM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Usability Question--Update #2
?
Going
to the west side, I told it to go to Mizar.? It was not very close (not on
the finder, but it was on the Telrad).? I centered, clicked
Menu>Align>Alignment.? And declared victory for the modeling.
***
Now
that you can do it, go back to the instructions or videos or whatever and build
a *better* model.. You put 4 stars into the East Model, but only one into the
West..
But..
YEAH! WOOO HOOO! :-))
Derek
?
?
?
We
had a clear night tonight, with no wind or moon.? So out I went again.
?
After
polar aligning with Polemaster (probably not necessary, since the tripod
hadn¡¯t moved, but good practice), I turned off the hand controller, put
it in CWD position, then did a cold start.?
?
I
told it to go to Altair (east side); it wasn¡¯t on the finder scope, but
it wasn¡¯t too bad.? I centered, and clicked
Menu>Align>Alignment.? I then told it to go to Deneb.? It
wasn¡¯t far off center on the illuminated reticle eyepiece; I centered,
and clicked Menu>Align>Alignment.? I told it to go to Vega, and
repeated the process (it was very close to center).? Finally, I did
Alberio (I like Alberio, so I¡¯ll use any excuse to look at it).? It
also was close to centered.
?
Going
to the west side, I told it to go to Mizar.? It was not very close (not on
the finder, but it was on the Telrad).? I centered, clicked
Menu>Align>Alignment.? And declared victory for the modeling.
?
I
substituted a 26mm Nagler Type 5 as my eyepiece, and told it to go to M27 (east
side).? It was pretty well centered.? Repeated for a number of east
side targets, all with good success.? Told it to go to M81 (west side); it
wasn¡¯t so well centered, but it was on the eyepiece.? Told it to go
to M31 (east side); it was at the very edge of the field of the 26mm
Nagler.? Told it to go to M57, and it was reasonably well centered.
?
I
think that this probably is as good as it gets.? I¡¯ve heard all the
people saying that I¡¯m too optimistic expecting everything to be
centered, so I¡¯ll accept the imperfections.? It¡¯s good enough
for my limited needs.
?
I
thank everyone for their help, particularly Brian Valente.
?
I
wish everyone clear skies, and a good night.
?
Mark
de REgt
?
?
I
went through all of the suggestions made, and collected those that seemed might
possibly be connected to my problem.? Then I implemented them.
?
Last
night was a test.
?
I
carefully determined the CWD position. ?Although, to be honest, there is
absolutely no way I know of to know when the counterweight bar really is
pointing as down as it can, since a bubble level depends on catching exactly
the right part of the curve, and not moving it at all.? But I also
understand that that matters only for the first slew.
?
I
slowed the speed at which the mount slews, to lessen the probability that
anything skips with the sudden torque.
?
I
did a careful polar alignment with PoleMaster.
?
I made
sure that time, date, and place were all very accurate.
?
I
deleted any existing model.
?
I
sent the mount to Altair.? It missed by a fair amount.? I decided
that maybe I should only ¡°center¡± using ¡°center¡± or
¡°guide,¡± not ¡°move¡± or ¡°slew,¡± so it took a
while to center Altair.? After carefully centering Altair on my
illuminated-crosshair eyepiece, I selected ¡°Menu,¡± then
¡°Align,¡± then ¡°synchronize.¡±
?
I
told it to go to Vega.? It was almost perfectly centered.? I
centered, synced, then told it to go to Deneb.
?
It
was perfectly centered.
?
The
west side of my sky is pretty much destroyed with Seattle sky glow and trees.? So I
decided to play on the east side, to see how it worked,?
It worked very well!? Everything I told it to go to was reasonably well
centered.
?
Then
I told it to go to Mizar, very much on the west side, but easy to see.
?
It
missed by a lot.? I centered it, and synced.
?
I
told it to go back to Deneb.? It was on the eyepiece (17mm Nagler Type 4,
on a Celestron 11¡± EdgeHD), but quite far off center.? I centered
and synced.? Told it to go to M27.? It was centered pretty
well,? I told it to go back to Mizar, and it barely was on the eyepiece.
?
And
so the night went.? I found no way to get it to converge on a model that
got everything reasonably close to the center of the eyepiece (I wouldn¡¯t
care so much, except that it¡¯s a royal PITA to center anything, to me, on
a GEM, since I have no idea which of the four buttons to hit at any time to get
it to move in any particular direction).
?
It
was somewhat promising, in that it always got the target on the (very, very
wide) eyepiece, but it is far, far from perfect.
?
Mark
|
Mark glad to hear things improved
>>> And declared victory for the modeling.
haha yes, i love that sentiment ;)
On Mon, Aug 22, 2022 at 10:47 PM Mark de Regt < deregt@...> wrote: We had a clear night tonight, with no wind or moon.? So out I went again. ? After polar aligning with Polemaster (probably not necessary, since the tripod hadn¡¯t moved, but good practice), I turned off the hand controller, put it in CWD position, then did a cold start.? ? I told it to go to Altair (east side); it wasn¡¯t on the finder scope, but it wasn¡¯t too bad.? I centered, and clicked Menu>Align>Alignment.? I then told it to go to Deneb.? It wasn¡¯t far off center on the illuminated reticle eyepiece; I centered, and clicked Menu>Align>Alignment.? I told it to go to Vega, and repeated the process (it was very close to center).? Finally, I did Alberio (I like Alberio, so I¡¯ll use any excuse to look at it).? It also was close to centered. ? Going to the west side, I told it to go to Mizar.? It was not very close (not on the finder, but it was on the Telrad).? I centered, clicked Menu>Align>Alignment.? And declared victory for the modeling. ? I substituted a 26mm Nagler Type 5 as my eyepiece, and told it to go to M27 (east side).? It was pretty well centered.? Repeated for a number of east side targets, all with good success.? Told it to go to M81 (west side); it wasn¡¯t so well centered, but it was on the eyepiece.? Told it to go to M31 (east side); it was at the very edge of the field of the 26mm Nagler.? Told it to go to M57, and it was reasonably well centered. ? I think that this probably is as good as it gets.? I¡¯ve heard all the people saying that I¡¯m too optimistic expecting everything to be centered, so I¡¯ll accept the imperfections.? It¡¯s good enough for my limited needs. ? I thank everyone for their help, particularly Brian Valente. ? I wish everyone clear skies, and a good night. ? Mark de REgt ? ? I went through all of the suggestions made, and collected those that seemed might possibly be connected to my problem.? Then I implemented them. ? Last night was a test. ? I carefully determined the CWD position.? Although, to be honest, there is absolutely no way I know of to know when the counterweight bar really is pointing as down as it can, since a bubble level depends on catching exactly the right part of the curve, and not moving it at all.? But I also understand that that matters only for the first slew. ? I slowed the speed at which the mount slews, to lessen the probability that anything skips with the sudden torque. ? I did a careful polar alignment with PoleMaster. ? I made sure that time, date, and place were all very accurate. ? I deleted any existing model. ? I sent the mount to Altair.? It missed by a fair amount.? I decided that maybe I should only ¡°center¡± using ¡°center¡± or ¡°guide,¡± not ¡°move¡± or ¡°slew,¡± so it took a while to center Altair.? After carefully centering Altair on my illuminated-crosshair eyepiece, I selected ¡°Menu,¡± then ¡°Align,¡± then ¡°synchronize.¡± ? I told it to go to Vega.? It was almost perfectly centered.? I centered, synced, then told it to go to Deneb. ? It was perfectly centered. ? The west side of my sky is pretty much destroyed with Seattle sky glow and trees.? So I decided to play on the east side, to see how it worked,?
It worked very well!? Everything I told it to go to was reasonably well centered. ? Then I told it to go to Mizar, very much on the west side, but easy to see. ? It missed by a lot.? I centered it, and synced. ? I told it to go back to Deneb.? It was on the eyepiece (17mm Nagler Type 4, on a Celestron 11¡± EdgeHD), but quite far off center.? I centered and synced.? Told it to go to M27.? It was centered pretty well,? I told it to go back to Mizar, and it barely was on the eyepiece. ? And so the night went.? I found no way to get it to converge on a model that got everything reasonably close to the center of the eyepiece (I wouldn¡¯t care so much, except that it¡¯s a royal PITA to center anything, to me, on a GEM, since I have no idea which of the four buttons to hit at any time to get it to move in any particular direction). ? It was somewhat promising, in that it always got the target on the (very, very wide) eyepiece, but it is far, far from perfect. ? Mark
-- Brian?
Brian Valente astro portfolio? portfolio astrobin?
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Michael Herman
Paul Kanevsky