Is polar alignment necessary when using a guide scope?

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Rmdigby
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Is polar alignment necessary when using a guide scope?

#1

Post by Rmdigby »


So, if I manually locate an object of interest and activate the guide scope, do I have to complete the normal alignment steps first? (equatorial mount)
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yobbo89 Australia
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Re: Is polar alignment necessary when using a guide scope?

#2

Post by yobbo89 »


Yes, to a point, if pa is way out tracking my not keep up, it uses very fine soft nudges, you might have this eradict movement that would be feeding back into the system, an example I had float play in my worm and guiding was chasing that rocking of the worm, it's best to eliminate as much as error as possible before auto guiding takes over
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JayTee United States of America
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Re: Is polar alignment necessary when using a guide scope?

#3

Post by JayTee »


First off, have you read this post:. viewtopic.php?f=42&t=914

To add to that post, your goal for your EQ mount is to get your polar alignment so close that you actually don't need guiding meaning that normal tracking is holding the object right in the center of the field of view. As Yobbo pointed out, guiding is the final fine-tuning step to hold the object absolutely motionless within the field of view.

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∞ Primary Scopes: #1: Celestron CPC1100 #2: 8" f/7.5 Dob #3: CR150HD f/8 6" frac
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KathyNS Canada
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Re: Is polar alignment necessary when using a guide scope?

#4

Post by KathyNS »


Yes, you do. If you did a good rough polar alignment with compass and level, AND if you keep your exposures short enough, AND if you are aiming at a part of the sky where rotation is not too severe, it is possible that the tracking errors will not be obvious. But they will be there.

The field of view will rotate around your guide star. It is possible to identify your guide star in the image just by finding the centre of rotation.
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DSO AP: Orion 200mm f/4 Newtonian Astrograph; ATIK 383L+; EFW2 filter wheel; Astrodon Ha,Oiii,LRGB filters; KWIQ/QHY5 guide scope; Planetary AP: Celestron C-11; ZWO ASI120MC; Portable: Celestron C-8 on HEQ5 pro; C-90 on wedge; 20x80 binos; Etc: Canon 350D; Various EPs, etc. Obs: 8' Exploradome; iOptron CEM60 (pier); Helena Observatory (H2O) Astrobin
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dcrowson United States of America
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Re: Is polar alignment necessary when using a guide scope?

#5

Post by dcrowson »


It is a bit confusing as to what you're asking. For imaging, you do need to be polar aligned. Once done, you can manually move the telescope to objects if you want and activate guiding. A lot of the guiding programs will take into account where you're pointing so results may vary if you do this.

Dan
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Re: Is polar alignment necessary when using a guide scope?

#6

Post by Baskevo »


Looking at @JayTee auto guide overview post, I had a quick question: You don't need additional camera control software to be able to auto-guide, do you? the guiding software like PHD2 can be the guide camera control software right? Or am I mistaken and you have to connect your imaging camera to be able to auto guide accurately?
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Re: Is polar alignment necessary when using a guide scope?

#7

Post by bobharmony »


Baskevo wrote: Sat Sep 21, 2019 10:19 pm Looking at @JayTee auto guide overview post, I had a quick question: You don't need additional camera control software to be able to auto-guide, do you? the guiding software like PHD2 can be the guide camera control software right? Or am I mistaken and you have to connect your imaging camera to be able to auto guide accurately?
PHD2 is all that is necessary for the guiding camera, you are correct. The imaging camera doesn't participate in guiding (unless you are using an off axis guider, a subject for another day).

Bob
Hardware: Celestron C6-N w/ Advanced GTmount, Baader MK iii CC, Orion ST-80, Canon 60D (unmodded), Nikon D5300 (modded), Orion SSAG
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