Polar alignment tips

[Astro_mark_c]

Hi, 

 

I still suck at manual polar alignment, are there any tips on what I’m looking for when viewing through my pole scope? All the stars look bright to me. 
 

i have the EQM 35 pro and Skywatcher Evostar 72 Ed telescope. 
 

thanks 

Edited January 9, 2021 by Sidecontrol

[discardedastro]

It still eludes me, really!

I find it's really helpful to get yourself comfortable viewing the polar scope so you're not rushing. Bring a phone with Stellarium or similar so you can look at a star atlas. Before you even get down there, use your phone's compass (after doing the figure-of-8 calibration) or a real compass to get the alignment "close" - you can do this in daylight in the "warm". Same goes for latitude alignment - level the tripod/base and set accordingly for your latitude.

I then use the star atlas to work out which bright star I'm looking at (once I have one) and navigate from there.

In the end I gave up and bought a Polemaster which has been transformative, though it still requires getting the "rough" fix right from the outset. I use a combination of this and PHD2's drift alignment for my imaging set-up (drift alignment for the fine alignment once the Polemaster's done).

[Gazereths]

I suck at it as well! I was looking into certain apps that might help but none I've tried so far have been great, I just don;t think my smartphone is accurate enough with it's sensors to be of any real help. At least you have a polar scope on yours!

One of the app's I've tried shows you what you should see through a polar scope from your GPS coordinates, but getting it to match is still the trick 😛

Star walk 2 is a decent app for general finding of stars/planets, but like I said it's no where near accurate enough for aligning imo. If you do get that app it's worth it to get the paid version as the free version blasts fullscreen ads at you every so often, ruining your night vision.

[AlexK]

Sadly, you forgot to mention your telescope and mount models. Knowing what you have to deal with would attract more folks with the same or similar instrument willing to share their experience with it (you can add it to your forum signature to save the time in the future). 

But in general, if you don't want to learn for too long and just need the result get a cheap green laser pointer (GLP), set you scope to point to the pole (0/90 on both setting circles or command it to go-to there), and just shine your GLP into the installed low power eyepiece. Match the end of the green beam exiting from your telescope with the Polaris (I hope you know how to find it in the sky naked eye? Big Dipper, Little Dipper...). Then work with the optical pole finder for more accurate PA. There are not too many bright stars around Polaris in the FOV of a typical pole finder to worry about.

For those no familiar with the starry sky at all, I know a person using his Android tablet with my star chart app in mirrored mode and 180 degrees FOV set on the screen. He is placing the tablet on the table using Polaris to orient it North-South and referencing bright stars from it as if he is in the center of the chart and seeing the sky's reflection in it. He is already quite proficient in Northern constellations! Some other charting apps may have a similar feature as well.

Edited January 9, 2021 by AlexK

[discardedastro]

Will add to AlexK's good tips there that if you do use a laser pointer be very sure there are no aircraft anywhere near where you're pointing!

[Gazereths]

12 minutes ago, AlexK said:

Sadly, you forgot to mention your telescope and mount models. Knowing what you have to deal with would attract more folks with the same or similar instrument willing to share their experience wit them.

But in general, if you don't want to learn for too long and just need the result get a cheap green laser pointer (GLP), set you scope to point to the pole (0/90 on both setting circles or command it to go-to there), and just shine your DLP into the installed low power eyepiece. Match the end of the green beam exiting from your telescope with the Polaris. Then work with the optical pole finder for more accurate PA.

That's a fantastic tip! I suppose that method could be used instead of using a finder scope/red dot finder while looking for specific stars/planets/DSO's as well? I'm gonna get one for sure as the finders on my scopes are not up to much, and my small scope's finder is always in an awkward position.

[AlexK]

5 minutes ago, Gazereths said:

That's a fantastic tip! I suppose that method could be used instead of using a finder scope/red dot finder while looking for specific stars/planets/DSO's as well? I'm gonna get one for sure as the finders on my scopes are not up to much, and my small scope's finder is always in an awkward position.

Sure thing you can! Just keep it safe (for passing aircrafts and yourself, as the back reflection from the eyepiece eye lens may blind you).

A red dot finder (RDF) will work as well, actually. And is in fact a preferable way, but it has some issues indeed.

Edited January 9, 2021 by AlexK

[Gazereths]

14 minutes ago, AlexK said:

Sure thing you can! Just keep it safe (for passing aircrafts and yourself, as the back reflection from the eyepiece eye lens may blind you).

A red dot finder (RDF) will work as well, actually. And is in fact a preferable way, but it has some issues indeed.

Yeah I'll be safe and considerate of aircraft for sure. Maybe I could make an adapter for the focuser so the GLP can sit in there. Does it need to go through an eyepiece?

[AlexK]

11 minutes ago, Gazereths said:

Yeah I'll be safe and considerate of aircraft for sure. Maybe I could make an adapter for the focuser so the GLP can sit in there. Does it need to go through an eyepiece?

Yes, the EP is a must, and it must be focused at infinity, as the whole point is to keep the laser beam collimated (otherwise it will fade very quick and will be useless for pointing). But if you plan an adapter for a particular telescope, you can try to reach the focusing lens inside of the GLP and try adjusting its focus to match your telescope objective (it need to produce an expanding cone matching your objective focal range). Just watch the beam, it must exit your telescope collimated. Or you can dedicate some cheap EP for that (still both need to be focused at infinity in the telescope).

Edited January 9, 2021 by AlexK

[Gazereths]

3 minutes ago, AlexK said:

Yes, the EP is a must, and it must be focused at infinity, as the whole point is to keep the laser beam collimated (otherwise it will fade very quick and will be useless for pointing). But if you plan an adapter for a particular telescope, you can try to reach the focusing lens inside of the GLP and try adjusting its focus to match your telescope objective. Just watch the beam, it must exit your telescope collimated. Or you can dedicate some cheap EP for that (still both need to be focused at infinity).

Ahh yeah that makes sense, it would just scatter otherwise.  I have a cheap 25mm eypiece I might use, but will experiment first, thanks for the tips!!

[AlexK]

No prob. But perhaps it would be easier to simply install the pointer on the OTA or even on the mount in parallel with the optical axis? I'm using just 2 ropes on my Astroscan:

  a) - pointer;  d) e) f) ropes.
 

Edited January 9, 2021 by AlexK

[Gazereths]

8 minutes ago, AlexK said:

No prob. But perhaps it would be easier to simply install the pointer on the OTA or even on the mount in parallel with the optical axis? I'm using just 2 ropes on my Astroscan:

  a) - pointer;  d) e) f) ropes.
 

Yeah I was just thinking that might be simpler, i'll have to look at my mount to see where it could be positioned, but hopefully something like this:

 

 

Or on my smaller MAK/DOB scope I could just strap it to the existing finder?

I was actually thinking of trying my air rifles illuminated reticle scope, but I think this will be a better option. And much lighter and easier to balance.

[Tiny Clanger]

1 hour ago, Gazereths said:

Yeah I'll be safe and considerate of aircraft for sure. Maybe I could make an adapter for the focuser so the GLP can sit in there. Does it need to go through an eyepiece?

Mansfield is , what, 15 miles from Nottingham Airport ? Please read up on UK law about lasers, even accidentally pointing them near a 'plane can get you in trouble. Our laws are a lot stricter than those in the USA, I seem to recall some new legislation was enacted a few years back with harsher penalties after pilots reported a lot of problems.

[Moonshed]

7 hours ago, Tiny Clanger said:

Mansfield is , what, 15 miles from Nottingham Airport ? Please read up on UK law about lasers, even accidentally pointing them near a 'plane can get you in trouble. Our laws are a lot stricter than those in the USA, I seem to recall some new legislation was enacted a few years back with harsher penalties after pilots reported a lot of problems.

I second Tiny Clanger on the care needed on the use of lasers, I wouldn’t  dream of using one to point all over the sky, and not overlooking the dangers at ground level either.

I would suggest that the OP uses one of the star chart apps to help recognise Polaris, it’s a lot easier than you may think and dead easy to find with the naked eye, and use that as your guide. If after that you continue to find  it problematic then ease your pain and buy a PoleMaster, I know they are not cheap and I resisted at first, but after I had purchased one it became one of the best astro investments I have made.

Good luck, hope it all works out for you.

[Astro_mark_c]

10 hours ago, AlexK said:

Sadly, you forgot to mention your telescope and mount models. Knowing what you have to deal with would attract more folks with the same or similar instrument willing to share their experience with it (you can add it to your forum signature to save the time in the future). 

But in general, if you don't want to learn for too long and just need the result get a cheap green laser pointer (GLP), set you scope to point to the pole (0/90 on both setting circles or command it to go-to there), and just shine your GLP into the installed low power eyepiece. Match the end of the green beam exiting from your telescope with the Polaris (I hope you know how to find it in the sky naked eye? Big Dipper, Little Dipper...). Then work with the optical pole finder for more accurate PA. There are not too many bright stars around Polaris in the FOV of a typical pole finder to worry about.

For those no familiar with the starry sky at all, I know a person using his Android tablet with my star chart app in mirrored mode and 180 degrees FOV set on the screen. He is placing the tablet on the table using Polaris to orient it North-South and referencing bright stars from it as if he is in the center of the chart and seeing the sky's reflection in it. He is already quite proficient in Northern constellations! Some other charting apps may have a similar feature as well.

Yeah noticed I forgot to mention my gear, have updated.

 

[AlexK]

To drastically reduce the risk of any law enforcement responding to pilots complaint in your neighborhood use the GLP only momentary when pointing. The probability you hit a plane by an accident are on par with the meteorite landing in your backyard. The image with the GLP in the pole finder port above shows the sleeve over the GLP button which is pushing it permanently. Instead, I would recommend airsoft gunsights GLP types with the remote trigger you can stick anywhere on the OTA/mount. E.g.:

(https://www.amazon.com/Twod-Picatinny-Adapter-Remote-Pressure/dp/B01NCHTID5)

That particular one also has some axis adjustments under the caps (quite limited though). I have one with some modifications on my shotgun for some years, quite decent piece of gear.
By the way, the aluminum weaver mount on it is removable (some folks don't know that), and comes with the tail cap button (which is interchangeable with that remote release cap).

I'm personally against GLPs for telescope pointing in favor of collimating sights (Telrad, QuInsight), as GLP beam is ruining the darkness adaptation (unless you go with the red beam, but the latter is hard to use in a light polluted sky). However, for the PA task it should be OK as you are using it only once per night during the setup. I do have GLP, RLP, and even BLP in my astro-bag primarily for outreach tasks though. And sure thing in some cases that might be the only viable way to point, e.g. my Astroscan when used on the laps or in hands on the neck strap.

[M40]

On 09/01/2021 at 00:10, Sidecontrol said:

Hi, 

I still suck at manual polar alignment, are there any tips on what I’m looking for when viewing through my pole scope? All the stars look bright to me. 

i have the EQM 35 pro and Skywatcher Evostar 72 Ed telescope. 

thanks 

Here's my little routine and it works on the basis that your finder is set as good as it can be, so set your finder on a star at night rather than a daytime object. Make sure your polar scope is aligned correctly with your mount.

Set the mount to it's home position. Plonk your telescope on the mount and using the lowest value eyepiece you have, center polaris in your finder and your telescope using the polar alignment adjustments. Hopefully polaris will now at least be on your polar scope target area. It will be brighter than the other stars in your polar scope. Rotate the telescope the 90' so you can see through the polar scope and then just carry out the polar alignment as normal. 

There was a superb post on here recently and I kept this link, have a look as it works well and is easy to follow.... https://darkskies.space/easy-polar-alignment/

Hope it helps.

[Astro_mark_c]

Thank you everyone that commented, I nailed SharpCap tonight after using my phone compass. Got PA in around 5mins so super pleased that the tips helped. 
 

cheers