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Celestron AVX mount question

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#1 Space Hunter

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Posted 06 August 2014 - 07:23 PM

as far as tracking settings what should i be using bc if i aglin it to say the moon and walk away and come back in 10 min its off target?



#2 RTLR 12

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Posted 06 August 2014 - 11:10 PM

You need to have to tracking set on "Lunar", but if the target still drifts it is because of your polar alignment being off.

 

Stan



#3 Space Hunter

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Posted 07 August 2014 - 12:43 AM

i put it on lunar even if im not looking at the moon? if im looking at nebs i still use lunar?



#4 RTLR 12

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Posted 07 August 2014 - 04:01 AM

You use Lunar for looking at the moon only. If you are looking at planetary or deep space you use sidereal. Your polar alignment affects tracking, so if your target drifts out of view, it is because of your polar alignment being off.

 

Stan



#5 Space Hunter

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Posted 07 August 2014 - 08:58 AM

yeah i no people can aglin a target leave for like an hour come back and its still centered i need to do that lol



#6 RTLR 12

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Posted 07 August 2014 - 09:19 AM

I can align my CG-5s or CGEMs and they will track an object for hours. I set up for public outreach and never have to realign for the entire night. That's with a 13mm or 17mm in my C8 or a 6mm or 8mm in my refractors.

 

Stan 



#7 RTLR 12

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Posted 07 August 2014 - 09:22 AM

With practice you will get better with your 2 + 4 alignments and your polar alignments. Do you use ASPA or a polar scope?

 

Stan


Edited by RTLR 12, 07 August 2014 - 09:22 AM.


#8 Space Hunter

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Posted 08 August 2014 - 07:42 PM

none all i do it have my gps on then 2 star aglin and then 2 additional calabrated stars and then my goto is on target but i dont think my mount is tracking or guiding bc after say 5 min of walking away and coming back the object is no longer in my eyepiece and this is hurting me with long exposures of nebula too many star trails



#9 RTLR 12

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Posted 08 August 2014 - 07:50 PM

You have to do a polar alignment. You will not get good tracking or round stars without it!

 

Stan



#10 Jeff2011

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Posted 08 August 2014 - 09:07 PM

Star Hunter,

 

if you don't have one already, I recommend getting a good planetarium program for your smart phone or tablet.  It will help you locate stars for your alignment processes.  I use Sky Safari Pro and would be lost without it.

 

The manual that comes with the AVX is not the greatest, but has all the information you need to do a polar alignment.  I recommend you carefully read it again.



#11 mclewis1

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Posted 09 August 2014 - 02:04 PM

1) Goto alignment (the initial alignment) and polar alignment are different and while they can affect each other you can have a good one without the other. For tracking accuracy it's all about the accuracy of the polar alignment. For goto (pointing) accuracy it's all about how well the initial alignment is done.

 

This applies to EQ oriented mounts (in this topic the gem style AVX). It does not apply to alt az oriented mounts. With an alt az mount the tracking accuracy IS affected by how well you do the initial alignment (there is no polar alignment done).

 

2) GPS (or any highly accurate time/date) has NO effect on the quality of your initial alignment. Highly accurate time/date data affects how well the mount points to the initial alignment stars and once done how well it points to solar system objects .... but for DSOs the pointing accuracy is all about how well you do the initial alignment (good stars chosen, well centered, 3-4 calibration stars, backlash mitigated).



#12 Space Hunter

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Posted 09 August 2014 - 08:35 PM

i did a polar aglinment i can have an exposure of about 40 seconds right now b4 i start to see any blur or star trails so im getting better still wont be able to have like an hour exposure or anything close yet though



#13 RTLR 12

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Posted 09 August 2014 - 08:42 PM

Well, You will have to use a guide program to get longer exposures. The longest I can get with my CG-5s or CGEM is about 90 sec unguided.

 

Stan



#14 TCW

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Posted 11 August 2014 - 07:58 PM

You use Lunar for looking at the moon only. If you are looking at planetary or deep space you use sidereal. Your polar alignment affects tracking, so if your target drifts out of view, it is because of your polar alignment being off.

 

Stan

If you use the auto locate for the moon does the mount switch to the Lunar rate automatically?



#15 RTLR 12

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Posted 11 August 2014 - 09:32 PM

No...You have to do that manually. 

 

Stan



#16 Maverick199

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Posted 14 August 2014 - 12:50 PM

Stan has already stated what should be done. One point I can add here is check if your scope is correctly balanced.



#17 NicholasP

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Posted 18 August 2014 - 06:31 AM

Is there any way to modify the default sidereal rate.....??????

 

They say that this is the rate that follows the rotation of the earth....but is there any way to change its speed ?????

 

Nikolas.



#18 RTLR 12

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Posted 18 August 2014 - 08:32 AM

What speed do you want to change it to?

 

Stan



#19 NicholasP

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Posted 18 August 2014 - 09:39 AM

What speed do you want to change it to?

 

Stan

Hi RTLR12, 

 

something like slower or faster....i mean if its possible of experiment...

at his moment i think it goes a bit fast or ofcourse maybe i am not good at Polar align.....

 

Thanks.



#20 RTLR 12

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Posted 19 August 2014 - 03:27 AM

The rate of speed is preset at sidereal, lunar and solar. It is not adjustable. If you are having trouble keeping the target centered in the EP and it drifts out of the feild of view, then you have a polar alignment problem. You will need to better align your mount using either a polar scope, ASPA, or drift alignment.Be sure to eliminate any mechanical problems that may effect your alignment first.

 

Stan



#21 NicholasP

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Posted 19 August 2014 - 04:54 AM

Thank you Stan, 

 

you are absolute correct !

 

Nikolas.



#22 MikeMiller

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Posted 26 August 2014 - 04:32 PM

Also, make sure the thing is level before starting alignment. A mistake I had made was to level it, then adjust the position of the tripod legs, thus knocking the leveling off. Another mistake I had made was not being completely sure the tripod was all the way open before balancing. Using a compass should get you close enough to north so you don't need to move the tripod once the mount is on. Then you can use the alt-az bolts to fine tune the polar alignment.

 

A problem I have with the AVX is that there does not seem to be a good way to level it once the mount is attached to the tripod. I haven't come up with a solution other than to be very careful I do not move the tripod once the mount is attached.

 

With the mount in the "home" position, you should be able to use the alt-az bolts to get right on the pole before powering the thing up. 


Edited by MikeMiller, 26 August 2014 - 04:37 PM.


#23 MikeMiller

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Posted 26 August 2014 - 04:44 PM

Also, are you using a SCT on it? At f/10 this thing is VERY sensitive to drift. I was not able to get any useful DSO images with this setup. Planetary and Lunar were fine since the exposures were so short.

 

Guiding and Focal Reducers will correct this. 

 

Hyperstar makes the optics so fast you could image with the mount switched off. :)



#24 seawolfe

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Posted 27 August 2014 - 03:55 AM

Also, are you using a SCT on it? At f/10 this thing is VERY sensitive to drift. I was not able to get any useful DSO images with this setup. Planetary and Lunar were fine since the exposures were so short.

 

Guiding and Focal Reducers will correct this. 

 

Hyperstar makes the optics so fast you could image with the mount switched off. :)

 

Hyperstar sounds wonderful....but unfortunately I don't own a money tree or treasure mountain with a nice dragon to protect the gold. :lol:

 

I'll just have to continue to use prime focus or piggy-back with my DSLR.  One of these days, I'd like to get the focal reducer for my Edge 8"....one of these days.... Maybe Smaug will let me have a handful of gold after all.  Hmm... :undecided:



#25 stryder

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Posted 27 August 2014 - 08:44 AM

The focal reducer makes all the difference...worth it. 


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