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Using Re-Alignment on CPC-1100

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#1 HeyJP

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Posted 05 October 2012 - 10:11 AM

Okay, I'm confused by what I thought should be obvious.

Last night I fired up the CPC-1100 and did an Auto 2-Star alignment. I picked Altair as my first star and used a regular eyepiece. Then used Mirach for the 2nd star, switching to my cross-hair eyepiece when i got close. I did a go-to M31, and it missed a bit. I assumed I had not done a good job centering Altair, so I thought I would re-align on Altair keeping the cross-hair eyepiece.

I slewed to Altair. Pressed ALIGN. Selected ALIGNMENT STARS. It asked "Replace Altair?" I pressed ENTER. It immediately told me to center Mirach.

So I hit Undo a couple of times and started over. This time I pressed ALIGN then ALIGNMENT STARS and selected Replace Mirach instead. Still it asked me to slew to Mirach.

How is this supposed to work? It seems that if I say "Replace Altair" it should let me pick the star to replace it with?

Also, once aligned there is no way to start a 2-star alignment over, right? I finally cut off my power and started over. Used my cross-hair on Altair and Mirach and had great alignment the rest of the night.

Any help understanding the logic of Re-Alignment would be appreciated.

Jim

#2 A. Viegas

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Posted 05 October 2012 - 11:39 AM

Hi Jim

Me too! I have never gotten re-alignment to work very well. I just turn off the power and re-do the auto-two star alignment routine. I think an important element is to pick two widely placed stars. I use this ancient Window 98 program called 'best pair' --> Best Pair

And try and pick a pair of stars I can see from my location (not always an easy job in and of itself!)

-Al

P.S. Make sure the tripod is level too! I know it sounds obvious, but on uneven driveway or grass it can make a big difference in accuracy

#3 barbarosa

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Posted 05 October 2012 - 11:58 AM

I slewed to Altair. Pressed ALIGN. Selected ALIGNMENT STARS. It asked "Replace Altair?" I pressed ENTER. It immediately told me to center Mirach.
Jim

Jim, did you slew to Altair by using the arrow keys or by selecting Altair from the list of named stars? The manual says to select the object for realignment from the database.

1. Select the desired star (or object) from the database and slew to it.
.........
3. Once centered, press the UNDO button until you are at the main menu.
4. With CPC Ready displayed, press the ALIGN key on the hand control.
5. The display will then ask you which alignment star you want to replace. Use the UP and Down scroll keys to select the alignment star to be replaced. It is usually best to replace the star closest to the new object. This will space out your alignment stars across the sky. If you have used one of the single object alignment methods then it is always best to replace the object that is “unassigned” with an actual object.
6. Press ALIGN to make the change.

Both realignment and precise go-to can be very helpful tools, although the CPC needs them less than the Nexstar mounts.

#4 HeyJP

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Posted 05 October 2012 - 12:10 PM

Did you slew to Altair by using the arrow keys or by selecting Altair from the list of named stars? The manual says to select the object for realignment from the database.


David,

THAT could be the point. I used SkySafari to slew back to Altair. I only use the keypad to do alignments. I do everything else wirelessly from SkySafari. I'll try that next time.

By the way, I do keep the tripod leveled. I got a good alignment once I re-did the complete Auto-2Star sequence with my Illuminated cross-hair eyepiece. My issue is how to properly use the Re-alignment capability.

Thanks a bunch to both of you!!!

Jim

#5 shiner

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Posted 05 October 2012 - 02:58 PM

Hi Jim,
I agree. I had exactly the same the other night (and spookily I was using the same stars as you !).

Not quite sure how this realignment works tbh....

Steve

#6 Peter in Reno

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Posted 05 October 2012 - 03:30 PM

I don't have Sky Safari but had similar issues with NexRemote with my old CPC0800. NexRemote and keypad don't know each other and I expect the same applies to Sky Safari. If I use two star alignments with NexRemote, the keypad is not aware of it and vice versa. It would be nice if Sky Safari had two star/re-alignment features then you would not need to use keypad anymore. With NexRemote, I don't even need a keypad connected to the scope.

Peter

#7 HeyJP

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Posted 08 October 2012 - 11:49 AM

Thanks for all your answers and thoughts. I'm pretty sure the issue is that I did NOT use the hand control to slew to the new object. I used SkySafari.

I will use the controller and slew by picking a new star from the hand controller database THEN try re-alignment.

Thanks all!

Jim

#8 barbarosa

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Posted 08 October 2012 - 12:38 PM

I don't have Sky Safari but had similar issues with NexRemote with my old CPC0800. NexRemote and keypad don't know each other and I expect the same applies to Sky Safari. Peter


Last night I confirmed that this is also true for Stellarium. I used the hand control for alignment and to slew to the Ring. I switched to Stellarium for comet 168P/Hergenrother. The hand control display still showed the Ring. Realignment would have been on the Ring and not the coordinates of the comet.

I then used the HC to select Jupiter and the mount made an accurate slew from the comet to the planet.

#9 rmollise

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Posted 09 October 2012 - 06:53 AM

The hand control may not display the position, but it know where it is, as you demonstrated.

That said, if you want to do a realignment for some reason, yeah, you do it with the HC.

#10 HeyJP

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Posted 12 October 2012 - 03:46 PM

Confirmed to my satisfaction last night.

In order to replace alignment stars or re-align, you DO have to use the hand controller to pick the star. While the hand controller "knows where you are pointing", it has no clue what object you commanded from SkySafari.

Proper procedure:
- Do a normal 2-star or Auto-2-star alignment.
- From the HC Lists command: Select Named Stars
- Scroll up or down to the star you want to re-align with and hit ENTER
- Telescope slews to where it thinks that star is
- Hit Undo until CPC Ready
- Hit Align
- Select Alignment Stars
- You can scroll to select which star to re-align or replace
- Select one of them with ENTER
- You will be asked to center the star you slewed to before.
- Normal alignment now. Rough center, press ENTER. Dead-on center, press ALIGN.

Done.

What I was doing wrong was slewing to my NEW star with SkySafari. Then when I tried to re-align, it would always say "Center Star XXXX" where XXXX was the last star I slewed to by the hand controller (which was always the 2nd star I aligned to since I used SkySafari after initial alignment).

Case closed. Works as expected. As long as you expect the unexpected.

Or something like that.

Jim






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