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#26 inZet

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Posted 04 September 2013 - 06:57 PM

I meant arcmin, of course. 30 arcsecs is the separation of Albireo... I only want to get the double in the field, I don't do position measurements. :-)

#27 WesC

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Posted 04 September 2013 - 07:00 PM

So far the only thing that affects my CGEMs gotos are how well I align those calibration stars and tripping over the tripod in the dark! ;)

If I get those two things right, my gotos are well within 20% of the center of my 11mm Nagler. And if I need dead-center tracking, I just sync to that object.

Good enough for me.

#28 jrcrilly

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Posted 04 September 2013 - 07:00 PM

I only want to get the double in the field, I don't do position measurements. :-)


Precise goto will get you where you need to be without having to buy anything. ;)

As soon as C integrates the starsense with the precise goto function it will be automatic. Then I'd buy the Starsense.

#29 rmollise

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Posted 04 September 2013 - 09:26 PM

I meant arcmin, of course. 30 arcsecs is the separation of Albireo... I only want to get the double in the field, I don't do position measurements. :-)


I don't know about this rig you are using, a Vixen with somebody's motor control board that allows you to use the NexStar HC, but Celestron's mounts will EASILY get your target in the field of such a small wide field scope if the alignment is done correctly. ;)

#30 orlyandico

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Posted 04 September 2013 - 10:11 PM

He's using the ASI120 which has a teeny tiny chip (probably equal to or smaller than a Mallincam chip). I think his problem is more of the soft ground (yes, wood under the tripod tips would help) and maybe not using UP and RIGHT for all final alignment corrections.

#31 rmollise

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Posted 05 September 2013 - 08:00 AM

He's using the ASI120 which has a teeny tiny chip (probably equal to or smaller than a Mallincam chip). I think his problem is more of the soft ground (yes, wood under the tripod tips would help) and maybe not using UP and RIGHT for all final alignment corrections.


Good catch... :goodjob:

#32 Jon_Doh

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Posted 05 September 2013 - 08:43 AM

[quote name="Spacetravelerx"][quote][quote]Rod is right. Unfortunately Celestron still has no competition when it comes to go-to pointing accuracy. Celestron software is still the most complex when using HC only. Skywatcher/Orion are still lagging behind in software go-to precision. [/quote]

Um, I have to dispute this claim "Celestron still has no competition...".

My LX850 provides excellent gotos (i.e. spot on), and I am pretty certain the same is true for the LX600. Like I said, once I am back home in New Mexico I will use my MallinCam to show how good the Meade setup is.

I cannot speak for all the other Meade units, but I simply have wonderful gotos on my LX200 and LXD75, though qualitatively speaking the LX850/LX600 are better. This is also one of many reasons I chose Celestron over Meade.

[/quote]

I have to agree. I've used both systems and Meade is way ahead of Celestron on ease of alignment and even the fine tuning process. Meade's Easy Align uses two stars that the GPS finds for you and it is as accurate as Celestron's 2+4 system..

Celestron is a popular option for refractors and why they can't simply their alignment process and make it more like Meade's is beyond me.

#33 rmollise

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Posted 05 September 2013 - 09:58 AM

Why? Part of the reason is that Meade sued them over their GPS 2-star alignment process for alt-az GPS scopes.

The other part is that for a _GEM_, a two-star alignment really doesn't work worth a frak. ;)

#34 Stew57

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Posted 05 September 2013 - 10:02 AM

And I have found the Celestron alignment easy enough and accurate to better than +-5 acrminutes. Granted the only Meade goto I am familiar with is the ETX80 I have so I won't compare accuracy, but for ease I wouldn't say it is all that much easier.

#35 inZet

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Posted 12 September 2013 - 08:17 AM

Wood under the tripod tips helped for sure.
Two days ago one of the rays that sustain the accessory tray broke, so I suspect the crack caused lack of rigidity.
Repaired in time for a quick check, now I can have the pointed object within 10 arcmin from the center of the eyepiece.

#36 Gil V

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Posted 12 September 2013 - 09:03 AM

What is an acceptable error for visual use, in your opinion? Is 5-10 arcminutes acceptable? I've just installed DSCs and I'm still in the learning curve.

#37 rmollise

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Posted 12 September 2013 - 10:00 AM

Yes, 10 or 15-minutes is pretty good.

#38 Gil V

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Posted 12 September 2013 - 02:24 PM

Thanks, Rod. I measured about nine arc minutes of error in my Dynamax mount over 12 hours. Frankly, I'm suprised it wasn't a lot worse.

#39 Ranger Tim

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Posted 12 September 2013 - 10:25 PM

You are using a reticle eyepiece for your reference stars, correct? I use a 9mm reticle eyepiece and get great go-to's with both my Sphinx and my GM-8. Most are dead center unless I am flopping back and forth over the meridian. Error tends to build if I work both hemispheres alternately. I stay in one then switch.

With a reticle ep for alignments I can get my mount set-up for a visual run easily. When imaging I use a camera and zoom the live view to the maximum to center alignment stars. Hey, it works!

#40 inZet

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Posted 13 September 2013 - 04:09 PM

I use a webcam and a software that plots a reticule on the screen. It's far more precise than eyepieces.
Beware to use full CCD resolution; most drivers use the upper-left frame only. For example if your camera has a 1280x1024 pixels and you select 640x480, you bet those pixels aren't in the center of your imaging area.
The result is, if you use a flip mirror, you could see the star not in the center of your eyepiece! Or, if you align based on 640x480 setup, it's like to align with the star not in the dead center of your eyepiece -- you can imagine the effect on pointing precision.

Gianluca

#41 oo_void

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Posted 13 September 2013 - 07:59 PM

http://sourceforge.n...illa/home/Home/


I agree with this one ... for ultimate pointing accuracy, plate solving is your friend.

#42 Doug Murphy

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Posted 13 October 2013 - 08:03 AM

Would Celestron's StarSense finder allow me to get 4-5 arcmin accuracy on my CPC 925 Edge HD mount?

#43 Stew57

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Posted 13 October 2013 - 09:23 AM

Iget better than that with a standard alignment with my CGEM. After adding the SSA it is just a bit better than the standard alignment. I am getting around 3 arcminutes or better.

#44 Raginar

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Posted 13 October 2013 - 09:25 AM

That's a spendy tool for that kind of a change how were your giros with precise goto on?

#45 Stew57

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Posted 13 October 2013 - 09:47 AM

It does not increase the pointing accuracy that much but it will do the alignment for you. It will also allowa high precision mode (adding calibration point) for the desired object, much easier. They do have bigger plans for it. It is missing a working ASPA at the moment. Now as to whether it is worth it at that price point for you, only you can answer that

#46 Raginar

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Posted 13 October 2013 - 09:53 AM

Yup.i agree. I guess I'm surprised at the number of people who find alignment troublesome.

#47 Doug Murphy

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Posted 13 October 2013 - 10:33 AM

My CPC 925 Edge arrives today, so have not used it yet. I do Mallincam imaging and had been using an Obsession truss Dob reflector, and although I could get pointing down to 4 arcsec on favorable nights, the system would settle and then objects were not in the FOV. The field was 17 arcmin with the reflector, so I needed 4 arcmin pointing accuracy to make life tolerable. I am hoping to get that on the CPC mount, so was thinking of the new StarSense.

#48 frank17601A

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Posted 13 October 2013 - 11:45 AM

What is needed is a Celestron Pro Division. They would slightly modify their handcontroller software and maybe motor controllers and sell that to folks like AP, Bisque and Losmandy.... I am sure I am oversimplifying it but why could not the Celestron HC software be modified to input gear and worm parameters etc? They could sell this technology to AP, Bisque. etc....and let these folks do the mechanical heavy lifting that they are so good at! The Celestron software even make the current overseas machining and assembly work reasonably. Imagine Celestron HC linked to the AP/Bisque/Losmandy quality!

Have you tried to buy a new AP handcontroller........1000 bucks! Retail....I can buy a new Celestron handcontroller....100 bucks...

Please don't move to have me executed!!! Imaging how good drivers etc would get when the software guys would only have to bother with ONE set of drivers for everyone..

I have owned AP, Bisque and Celestron, and quite frankly the Celestron HC is the most intuitive and full featured...

Just my opinion, let the arguments begin!

Frank

#49 Moromete

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Posted 13 October 2013 - 01:32 PM

Does anyone have experience and knows how good is pointing accuracy with a EQ6 PRO+C11 at ~100x magnification with firmware 3.35 on both sides of the meridian?

#50 rmollise

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Posted 13 October 2013 - 03:24 PM

Does anyone have experience and knows how good is pointing accuracy with a EQ6 PRO+C11 at ~100x magnification with firmware 3.35 on both sides of the meridian?


I have not had the opportunity to try 3.35, but the previous version would, with a decent (polar scope) polar alignment, put anything I requested in the field at this magnification. IF...

The secret is giving the SynScan the alignment stars it needs. The suggestions in the manual are more than that:

Stars 1 and 2 should be separated by at least 3-hours of right ascension. Also, try to pick two that are at least 20-degrees apart in declination, but separation in RA is more important.

Star 3 needs to be within a declination range of 30 and 70 degrees north and south.

More recent SynScan firmware is better at offering choices of alignment stars that fulfill the above, but still don't just blindly accept the first stars offered unless they do. ;)






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