Polaris moves in polar scope depending on

[TiffsAndAstro]

If I move my eye to the left/right...

How can I tell if I've lined it up with my eye in the right place. Wherever that is.

[malc-c]

For visual use, having Polaris on the circle or inside the small ring that sits on it is close enough.  If you were using the mount for imaging then some form of plate solving such as that used in Sharpcap is needed to get the alignment spot on 

[TiffsAndAstro]

5 hours ago, malc-c said:

For visual use, having Polaris on the circle or inside the small ring that sits on it is close enough.  If you were using the mount for imaging then some form of plate solving such as that used in Sharpcap is needed to get the alignment spot on 

In an hour or so I'm gonna try quick polar along, 3 maybe 2 star alignment then full polar alignment. 

 

Cue clouds

[malc-c]

21 hours ago, TiffsAndAstro said:

 3 maybe 2 star alignment then full polar alignment. 

 

It's normally the other way around.  You set the mount up so it's in the home position with the N leg pointing North.  Undertake Polar alignment using the long and latitude bolts, release the clutches and place the mount back into the default home position, lock them off and then run through the 2 or 3 start alignment routine

[bosun21]

Silly polar aligning after a three star alignment with the mount. Any adjustments to polar align will throw the previous three star alignment off. Polar align first everytime.

[Captain Scarlet]

On 23/02/2024 at 18:57, TiffsAndAstro said:

If I move my eye to the left/right...

How can I tell if I've lined it up with my eye in the right place. Wherever that is.

This is likely parallax between the focal plane of your polar scope’s objective (front) lens and that of the eyepiece or the position of the reticule plate.

First focus the eyepiece so the cross-hairs are in perfect focus. Then focus the main body of the polar scope to brings stars into focus. Then all the focal planes are at the same place and there should be no parallax. In other words any star should stay in the same place however much you move your eye.

If your polar scope is embedded in the mount you’ll need to remove it to do this. It should just unscrew from the mount.

Magnus

Edited February 25 by Captain Scarlet

[bosun21]

What mount do you have? A lot of the newer polar scopes you can focus with them in place.

[Franklin]

For visual, with a goto mount, your PA can be way off and the mount will compensate.

[TiffsAndAstro]

22 hours ago, bosun21 said:

Silly polar aligning after a three star alignment with the mount. Any adjustments to polar align will throw the previous three star alignment off. Polar align first everytime.

I have to do a 2 or or 3 star alignment first before synscan all will let me to a polar slign due to no mel or maz

 

I remember mel and Kim gonna have to google mel and maz

[TiffsAndAstro]

20 hours ago, bosun21 said:

What mount do you have? A lot of the newer polar scopes you can focus with them in place.

Sw gti

 

Think I might try an asi air do plar alignment in that

[TiffsAndAstro]

21 hours ago, Captain Scarlet said:

This is likely parallax between the focal plane of your polar scope’s objective (front) lens and that of the eyepiece or the position of the reticule plate.

First focus the eyepiece so the cross-hairs are in perfect focus. Then focus the main body of the polar scope to brings stars into focus. Then all the focal planes are at the same place and there should be no parallax. In other words any star should stay in the same place however much you move your eye.

If your polar scope is embedded in the mount you’ll need to remove it to do this. It should just unscrew from the mount.

Magnus

This is fantastic ty.

Parallax is a really good word to describe the effect I can see happen. In case it helps, if I try to look to the far extreme right I can see I little column of years. A bit like:

2026

2025

2024   .......

2023

However I'm so pro at this I thought there was only one ring to adjust polar scope focus. Will need to look for the plate thing you mention

Edited February 26 by TiffsAndAstro

[TiffsAndAstro]

Here is a terrible stack from last night. 60 sec subs stars look fairly trail free at least.

[AstroMuni]

20 hours ago, TiffsAndAstro said:

This is fantastic ty.

Parallax is a really good word to describe the effect I can see happen. In case it helps, if I try to look to the far extreme right I can see I little column of years. A bit like:

2026

2025

2024   .......

2023

However I'm so pro at this I thought there was only one ring to adjust polar scope focus. Will need to look for the plate thing you mention

Looks like you have a similar reticle to mine. If you look closely you will notice 3 circles in the clock face. The years tell you which of the circles to use for aligning Polaris. At the moment its the central ring. I wouldnt worry too much about parallax error. I have been doing polar alignment using the polarscope and my images havent been badly affected using exposure times between 30-60s without guiding. Good luck.

Edited February 27 by AstroMuni

[TiffsAndAstro]

Tbh I'm just doing quick pa through scope then doing pa via synscan app. Seems ok but not great.

[ollypenrice]

On 24/02/2024 at 19:07, TiffsAndAstro said:

In an hour or so I'm gonna try quick polar along, 3 maybe 2 star alignment then full polar alignment. 

 

Cue clouds

Polar alignment and software star alignment are totally different things.

Polar alignent physically points the RA axis of the mount towards the north celestial pole, near Polaris.  You are aligning the real metal mount so its RA rotation axis is parallel with the earth's axis.

Star alignment is an all-software procedure in which you are synchronizing the position of the stars in the sky with their positions in the virtual planetarium contained in your  mount's software. Using a 3 star alignment means you can do this synchronization with quite a poor physical polar alignment. If you have a very good polar alignment, a one star alignment will do.

Olly

[TiffsAndAstro]

Apologies I maybe mixing terms.

I do a very rough polar alignment get the pa scope pointed close to polaris. Add counter weight camera lens check balance. Then an accurate polar alignment via the pa scope and alt/az (i think that's their names) matching the Polaris position in synscap app. Then i do a 2 star align in the app. Then i do a polar alignment on a bright star or jupiter using the same physical knobs above. Then i select a star on or close to my target and do another polar align via app and physical knobs but it's usually spot on.

 

2 min exposures still seem too much though

[StevieDvd]

14 minutes ago, TiffsAndAstro said:

Apologies I maybe mixing terms.

I do a very rough polar alignment get the pa scope pointed close to polaris. Add counter weight camera lens check balance. Then an accurate polar alignment via the pa scope and alt/az (i think that's their names) matching the Polaris position in synscap app. Then i do a 2 star align in the app. Then i do a polar alignment on a bright star or jupiter using the same physical knobs above. Then i select a star on or close to my target and do another polar align via app and physical knobs but it's usually spot on.

 

2 min exposures still seem too much though

You should not touch polar alignment (PA) after a star align. So basically always end on a star align process.

This is because the star alignment lets the mount compensate for any PA error, this is ruined if you then adjust the PA again.

 

[TiffsAndAstro]

16 minutes ago, StevieDvd said:

You should not touch polar alignment (PA) after a star align. So basically always end on a star align process.

This is because the star alignment lets the mount compensate for any PA error, this is ruined if you then adjust the PA again.

 

Ok will do a 2 maybe a 3 star alignment after my pa in app using physical knobs.

 

Ty so much for this. It might be obvious to many people, but I'm very noob if you hadn't (or are too polite) to notice.

[malc-c]

On 25/02/2024 at 16:02, malc-c said:

It's normally the other way around.  You set the mount up so it's in the home position with the N leg pointing North.  Undertake Polar alignment using the long and latitude bolts, release the clutches and place the mount back into the default home position, lock them off and then run through the 2 or 3 start alignment routine

Forget the alignment process for now.    Polaris orbits the NCP, so you first need to know where Polaris is in its rotation for what ever time you are observing.  In the above example of the polarscope Polaris is about 10:40  (hence the 0, 3, 6, and 9 markings).  So placing Polaris on that centre line of the ring at that position will put the NCP in the correct place.   Simply putting Polaris anywhere on that ring won't work, as for example,  if you put polaris over the ring at the 3 O'clock position it would place the NCP way off to the left rather than to the right.  

Once you have correctly polar aligned DO NOT move the mount  other than releasing the clutch on the RA to place the mount back to the default home position with the weights down.  If you knock it or manually move the mount you'll undo all your hard work.  Once in the home position run the star alignment routine.  This normally involves picking a target, letting the mount slew to target, and then using the directional buttons on a handset, or on an app, centre the target star, then confirming it centred before selecting the second target.   Again, any adjustment to centre the star needs to be done by the mount control and NOT by releasing the clutches and manually centring the star.  This is so that the controlling method, be that a synscan handset or app works out all the offsets as a result of the polar alignment (you will never get it 100% spot on, but 99.9% is close) so that it can apply it to further gotos so the targets end up centred with little or no further adjustments.

Edited February 27 by malc-c
typo

[TiffsAndAstro]

19 hours ago, malc-c said:

Forget the alignment process for now.    Polaris orbits the NCP, so you first need to know where Polaris is in its rotation for what ever time you are observing.  In the above example of the polarscope Polaris is about 10:40  (hence the 0, 3, 6, and 9 markings).  So placing Polaris on that centre line of the ring at that position will put the NCP in the correct place.   Simply putting Polaris anywhere on that ring won't work, as for example,  if you put polaris over the ring at the 3 O'clock position it would place the NCP way off to the left rather than to the right.  

Once you have correctly polar aligned DO NOT move the mount  other than releasing the clutch on the RA to place the mount back to the default home position with the weights down.  If you knock it or manually move the mount you'll undo all your hard work.  Once in the home position run the star alignment routine.  This normally involves picking a target, letting the mount slew to target, and then using the directional buttons on a handset, or on an app, centre the target star, then confirming it centred before selecting the second target.   Again, any adjustment to centre the star needs to be done by the mount control and NOT by releasing the clutches and manually centring the star.  This is so that the controlling method, be that a synscan handset or app works out all the offsets as a result of the polar alignment (you will never get it 100% spot on, but 99.9% is close) so that it can apply it to further gotos so the targets end up centred with little or no further adjustments.

ty for your in depth reply - i have a couple of questions though, sorry

i line up polaris from its position given in the app through the polar scope and manage to match it pretty easily and quickly. i don't think im struggling with that part. 

why would the mount not be in the default home position? after using the polar scope i turn the dec 90 degrees (by eye) and lock its clutch. the ra i might adjust a tiny bit so it looks perpendicular to the ground in the polarscope then lock its clutch. 

next clear skies, right after positioning polaris correctly in the polar scope, i will then do a 2 (though its stopped working) or 3 star alignment (1 & 3 still seems to work fine) then chose the polar alignment option and do that  (which is use the bolts on the mount to adjust) then reset star alignment and do it again and i should be good?

i haven't been using ra and dec to do star alignments or polar alignments, apologies if this wasn't clear.

[malc-c]

4 hours ago, TiffsAndAstro said:

why would the mount not be in the default home position? after using the polar scope i turn the dec 90 degrees (by eye) and lock its clutch. the ra i might adjust a tiny bit so it looks perpendicular to the ground in the polarscope then lock its clutch. 

Because you need to rotate the mount around the RA axis to match the "hour" that Polaris is at for the time of using the mount.  This old video is using EQMOD to control the telescope, but basically you would do the same using the handset to rotate the mount to the polar hour, which means the mount will move off the default home position.
 

 

 

[TiffsAndAstro]

34 minutes ago, malc-c said:

Because you need to rotate the mount around the RA axis to match the "hour" that Polaris is at for the time of using the mount.  This old video is using EQMOD to control the telescope, but basically you would do the same using the handset to rotate the mount to the polar hour, which means the mount will move off the default home position.
 

 

 

Cant watch video right this second, but, is the gist of it that I move the ra away from what seems default, so that 12 on the clock in the scope is pointing straight down? If so, yes I already do that. Then I use the bolts alt az to put polaris at the correct position.

Last time I did it a little rougher expecting the polar align with the app to then correct it (vi alt az bolts)

 

[TiffsAndAstro]

sorry this video is confusing

The cross have in the bottom window doesnt match the upper one

And if it did, the small target circle for Polaris would be at 3pm not slightly before

 

 

 

2 hours ago, malc-c said:

Because you need to rotate the mount around the RA axis to match the "hour" that Polaris is at for the time of using the mount.  This old video is using EQMOD to control the telescope, but basically you would do the same using the handset to rotate the mount to the polar hour, which means the mount will move off the default home position.
 

 

 

Cant watch video right this second, but, is the gist of it that I move the ra away from what seems default, so that 12 on the clock in the scope is pointing straight down? If so, yes I already do that. Then I use the bolts alt az to put polaris at the correct position.

Last time I did it a little rougher expecting the polar align with the app to then correct it (vi alt az bolts)

 

Edited February 28 by TiffsAndAstro

[TiffsAndAstro]

Also this is very different to synscap app which is all I have

[TiffsAndAstro]

I'm just watching a video on YouTube Martins astrophotography.  I think shows what I need. Will try follow it asap