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Polar alignment tips for a beginner

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#1 Tom-UK

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Posted 18 May 2021 - 10:06 AM

Hello everyone.

 

Last night I managed to finally use my recent setup purchase consisting of the following:

 

- iOptron Skyguider Pro

- RedCat refractor 

- William Optics 32mm Slide-base Uniguide Scope

- ASI120MC-s as my guide camera

- Canon T3i 

 

I managed to take several 2 minute long exposures of the northern night sky. I have no idea what stars were in the image as I was merely trying to get to grips with everything. I did connect my laptop and tried to connect the guide camera, but this didn't work too well...but I rewatched Peter Zelinka's tutorial on setting up PHD2 for this so next time I should hopefully have a better understanding of what to do. I also has issues with getting the guide cam and scope into focus on the screen, but it's something i just need to perfect i'm sure.

 

Another issue i encountered was using the polar scope in the mount itself. The recticle doesn't seem to illuminate when 12 is in the correct position which was off putting, but also the recticle wasn't all that sharp. I also struggled to locate polaris through the polar scope ( I did locate it in the sky easily enough though). 

 

So i pretty much ended up roughly polar aligning the setup using a compass and ensuring the mount was level, as well as inputting the correct latitude. I need to practice this i know, it's just one of those things. 

 

Are there any pieces of software that can be used in conjunction with PHD2 (i've head of plate solving) to polar align this way? Or is polar aligning something that always needs to be done manually with the polar scope in the mount?

 

I was pretty shocked that i managed to get several 2' exposure images of various locations in the night sky without trailing. 

 

Any tips would be a huge help!

 



#2 Remenakb

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Posted 18 May 2021 - 10:12 AM

Purchase shaprcap pro and use it's polar alignment tool. I have great success with this and it is very easy. No need to look through a scope, just use your guide camera and follow the prompts in the software.


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#3 Mike in Rancho

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Posted 18 May 2021 - 10:17 AM

It's hard to focus in PHD2, even with faster exposures, because of the way it shows on the screen.  I use Sharpcap for that.  First in the daytime on a mountaintop to ballpark my infinity focus, then dial it in at night.  You may need to change some camera settings for daytime vs nighttime.  At least I did.

 

PHD2 I believe has three polar alignment functions built in.  I've used one of them, but that was to drift align a spot where I couldn't see Polaris.



#4 Tom-UK

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Posted 18 May 2021 - 10:32 AM

Thanks for your replies. So sharpcap could be a better option? I already have the free version installed an know (sort of) how it works. I was looking at the ioptron iPolar camera that you can install into the mount, but its another £200 I don't necessarily want to spend just yet. Id rather get to grips with how to do it properly, and then maybe invest in the ipolar at a later date to save time.

#5 francov

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Posted 18 May 2021 - 10:36 AM

+1 for using sharpcap pro for polar aligning. It's worth every penny.

I have gone to dark skies with the skyguiderpro, and I also struggled more than once to locate polaris through the polar scope and with shaprcap it's done in a minute or two. btw, the eyepiece on the polar scope rotates, that should help you put the reticle in focus.



#6 nyx

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Posted 18 May 2021 - 10:37 AM

The easiest way would be SharpCap Pro. You get a very good PA in no time and you don't need to crouch/go on your knees.

 

Still, I think you should take the time and learn how to PA using SGP's polar scope. I'd also suggest you read the manual thoroughly, which will answer most, if not all, of your questions :)

 

Glad you got your gear sorted out though :)


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#7 DubbelDerp

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Posted 18 May 2021 - 10:38 AM

It really is a pain to focus the guidescope at nighttime via PHD2. As mentioned above, try it in the daytime to get it close, and then dial it in at night on the stars.

 

You'll also need to focus the polar scope, and that is much easier to get close during the day as well. One of the rings at the eyepiece of the polar scope will focus it. Just pick a far off object during the day, and refine it at night. When trying to find Polaris in the scope, I like to keep both eyes open as if you're using a reflex site.

 

If the polar scope reticle isn't illuminated, try rotating the dec bracket 180 degrees in RA. Sometimes these things aren't aligned quite right in the factory. IOptron has a procedure on their website showing how to re-orient the dec bracket and scope so that it's positioned correctly.

 

Last thing, the Polar Drift Align tool in PHD2 works well for refining your polar alignment once you've done a rough alignment through the polar scope. I was able to do 180-second guided subs with mine by using this tool.



#8 Tom-UK

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Posted 18 May 2021 - 10:46 AM

I didn't realise Sharpcap pro was so cheap! Will definitely give it a go and hopefully that'll help me. Thanks for the tip!

#9 Tom-UK

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Posted 18 May 2021 - 10:48 AM

@nyx thanks for the help with choosing my gear, am happy with it all and eager to get some more shots. Today I've been researching callibration frames so I'm keep to give that a go tonight (weather permitting) as it seems fairly straight forward.

#10 kathyastro

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Posted 18 May 2021 - 11:03 AM

My advice would be to forget about guiding for a while until you learn the basics.  Guiding will be nice when you start taking longer exposures, but it is an unnecessary complication when starting out.

 

Learn to use the polar scope well.  Learn where the declination axis must be in order to open up the view port in the axis shaft.  Learn how to set up the mount so that Polaris is in the FOV of the polar scope.  Learn what the polar alignment adjustment knobs do: you will need them even if you use electronic aids eventually.  Learn where to position Polaris on the polar scope reticle.

 

It concerns me that you used the verb "input" for what you did with the latitude.  Yes, the electronics need to know the latitude, but I hope you realize that polar alignment requires a mechanical adjustment, not just an electronic input.

 

None of this will prevent you starting to take images.  On the contrary, it will give you the skills to take good images even when you get to your dark sky site and discover that you forgot to pack the laptop!


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#11 Tom-UK

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Posted 18 May 2021 - 11:08 AM

Great tips thanks Kathy. By "input I meant dialled it into the base, not electronically just for clarification! I do want to perfect and familiarise myself with the polar scope since its an essential part of the process. I also would like to take my gear for a session without my laptop at some stage, so obviously the manual polar alignment process is more than essential.

#12 Tom-UK

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Posted 18 May 2021 - 11:22 AM

So I've just spent some time with the mount and have now managed to get the recticle into focus and correctly illuminated, so hopefully that will help me the next time I polar align.
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#13 idclimber

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Posted 18 May 2021 - 12:26 PM

An excellent target for focus right now is the moon. It is pretty close to directly overhead as the sun sets. Doing this in when you can still see is a real luxury. The only trick is shortening the exposures enough so it does not bloom all over the sensor and you can see the detail. I did this the other day when setting up my big SCT. 



#14 alphatripleplus

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Posted 18 May 2021 - 01:43 PM

I didn't realise Sharpcap pro was so cheap! Will definitely give it a go and hopefully that'll help me. Thanks for the tip!

One of the nice features of SharpCap for polar alignment is that it is fast and accurate. As long as your camera/scope combination is within 5 degrees of the pole and has a field of view between 1degree and 2.5 degrees, it will get you very well polar aligned within a couple of arcminutes in 2-3 minutes.



#15 audioengr

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Posted 18 May 2021 - 02:14 PM

I also use SharpCap Pro for PA with my wedge.  Very fast.  I just use the numbers, not the star-trail.  Slew to Polaris, adjust gain and exposure to see a bunch of stars and start the PA under tools.



#16 Peregrinatum

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Posted 18 May 2021 - 02:24 PM

get a Polemaster and be done with it, best $300 I have spent on this hobby



#17 driddle007

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Posted 19 May 2021 - 12:42 PM

Thank you for this. I have been approaching my newbie state in this way. I have been learning for months on my own (thanks, youtube) and determined chipping away at things was the way to go. I've relied far too much on the digital and it's not really serving me that well. Also re: guiding, I'll get to it one day and hopefully not too far off in the future. For now, doomed to shots of the moon until I get the puzzle of astrophotography filled in a bit more. At least I can find the frikkin moon and achieve focus. :)

My advice would be to forget about guiding for a while until you learn the basics.  Guiding will be nice when you start taking longer exposures, but it is an unnecessary complication when starting out.

 

Learn to use the polar scope well.  Learn where the declination axis must be in order to open up the view port in the axis shaft.  Learn how to set up the mount so that Polaris is in the FOV of the polar scope.  Learn what the polar alignment adjustment knobs do: you will need them even if you use electronic aids eventually.  Learn where to position Polaris on the polar scope reticle.

 

It concerns me that you used the verb "input" for what you did with the latitude.  Yes, the electronics need to know the latitude, but I hope you realize that polar alignment requires a mechanical adjustment, not just an electronic input.

 

None of this will prevent you starting to take images.  On the contrary, it will give you the skills to take good images even when you get to your dark sky site and discover that you forgot to pack the laptop!




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