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Synscan location

RobertC

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RobertC

RobertC

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To be honest, unless your polar alignment is pretty sharp, I'd be surprised if it could even find the Moon after a single star align.

I'm going to give it a good go at the weekend where i can see a good amount instead of the back of my house. At least my cords are a little more correct now. Thanks for all the help guys :)

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RobertC

RobertC

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I cycle through them all checking where they are at the moment but i setup around 5ft from my house where it is sheltered from the wind and every single one offered for the 2nd star is behind my house. Is there anyway i can change the offered ones to one that i can actually see as i only get away from my garden once a week.

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JamesF

JamesF

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Hmmm.  In that situation I might be tempted to try drift-alignment using the camera and then go for a single star align knowing that the mount was set up well.  Someone else might be along with a better idea in the morning though.

James

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jambouk

jambouk

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Yes, you are west of Greenwich, the minus sign just means exactly this.

Make sure you are entering the time and date in the correct format. Are you taking into account day light saving somehow?

You don't need very accurate polar alignment for good GOTO accuracy. For accurate GOTOing, you just need good star alignment. I don't think you need to be doing drift aligning to solve this issue.

What I would try is:

- make sure you telescope is pointing in roughly the home position before starting a star alignment, so scope parallel to the RA axis, roughly pointing to Polaris (it doesn't matter if you can't see Polaris in the scope).

- I'd be tempted to re-boot up the mount/handset with the scope in this position after you have polar aligned (you will only have to re-enter the time as the coordinates and date will be retained and correct assuming you did them correctly the first time).

- start an alignment (ideally 3 star, but it sounds like you have a limited view of the sky. I suspect there are more alignment stars you could use, it's just a case of working out which ones; I wish there was a list of all the stars the handset uses for alignment stars (and I also wish the handset what constellation they were in as most of them I have no idea where they are). In Stellarium you can build your own foreground so could mimic your back garden, and fast forward the programme to see what stars will be visible when you are setting up, but this will all take some time and effort on your behalf.

- if you really only can manage a one star alignment, then pick a star near your target, as the GOTO is likely to be most accurate near that alignment star; as James says, if the target is a long way off any alignment star, it might be less accurate.

I have a very narrow field of view with my 180mm Mak, so I use a cross hair reticle 12mm eye piece to do a three star alignment to help get it as accurate as possible (and always end with an up and right arrow movement (usually at speed *1) to centre the star. It doesn't add much time to the process but does improve the accuracy.

Do you have much cone error? This will influence the accuracy of your GOTOing. The handbook for the mount/handset will talk about this. If you have lots (as I did), you need to resolve this to get your GOTOing to be better.

Is your kit all nicely balanced on the mount?

Is there much backlash in your mount? When all the clutches are locked, how much play is there in the RA and dec axes of the mount (can you rotate these axes by a few degrees as measured by the setting circles?). Again, I am convinced a lot of backlash in my mount resulted in poor GOTOing for me initially but now it's nearly all gone.

What I think you need to do, is to get to a more open place and do a bang-on three star alignment, and see if that improves things. Maybe even have a go at setting up at the front of the house if possible (even if there is more light pollution) to see if this resolves issues. If it does, then we need to identify why a one star alignment isn't hitting the mark.

I can't think of anything else for now.

There will be a solution so don't worry.

Are you a member of a local group? There will likely be a load of nerds [i mean helpful astronomers :)] who live near by who would be happy to help you out. Maybe start a thread in the local groups section of this website.

You can probably do some experimenting / testing / adjustments in the day light.

Do report back.

James

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ronin

ronin

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Concerning alignment, if Vega is visible then I would have thought that Deneb was also visible, it tends to be higher in the sky then Vega at this time of year. Not a great distance apart but at least 2 stars for the scope to play with.

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RobertC

RobertC

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Yes, you are west of Greenwich, the minus sign just means exactly this.

Make sure you are entering the time and date in the correct format. Are you taking into account day light saving somehow?

You don't need very accurate polar alignment for good GOTO accuracy. For accurate GOTOing, you just need good star alignment. I don't think you need to be doing drift aligning to solve this issue.

What I would try is:

- make sure you telescope is pointing in roughly the home position before starting a star alignment, so scope parallel to the RA axis, roughly pointing to Polaris (it doesn't matter if you can't see Polaris in the scope).

- I'd be tempted to re-boot up the mount/handset with the scope in this position after you have polar aligned (you will only have to re-enter the time as the coordinates and date will be retained and correct assuming you did them correctly the first time).

- start an alignment (ideally 3 star, but it sounds like you have a limited view of the sky. I suspect there are more alignment stars you could use, it's just a case of working out which ones; I wish there was a list of all the stars the handset uses for alignment stars (and I also wish the handset what constellation they were in as most of them I have no idea where they are). In Stellarium you can build your own foreground so could mimic your back garden, and fast forward the programme to see what stars will be visible when you are setting up, but this will all take some time and effort on your behalf.

- if you really only can manage a one star alignment, then pick a star near your target, as the GOTO is likely to be most accurate near that alignment star; as James says, if the target is a long way off any alignment star, it might be less accurate.

I have a very narrow field of view with my 180mm Mak, so I use a cross hair reticle 12mm eye piece to do a three star alignment to help get it as accurate as possible (and always end with an up and right arrow movement (usually at speed *1) to centre the star. It doesn't add much time to the process but does improve the accuracy.

Do you have much cone error? This will influence the accuracy of your GOTOing. The handbook for the mount/handset will talk about this. If you have lots (as I did), you need to resolve this to get your GOTOing to be better.

Is your kit all nicely balanced on the mount?

Is there much backlash in your mount? When all the clutches are locked, how much play is there in the RA and dec axes of the mount (can you rotate these axes by a few degrees as measured by the setting circles?). Again, I am convinced a lot of backlash in my mount resulted in poor GOTOing for me initially but now it's nearly all gone.

What I think you need to do, is to get to a more open place and do a bang-on three star alignment, and see if that improves things. Maybe even have a go at setting up at the front of the house if possible (even if there is more light pollution) to see if this resolves issues. If it does, then we need to identify why a one star alignment isn't hitting the mark.

I can't think of anything else for now.

There will be a solution so don't worry.

Are you a member of a local group? There will likely be a load of nerds [i mean helpful astronomers :)] who live near by who would be happy to help you out. Maybe start a thread in the local groups section of this website.

You can probably do some experimenting / testing / adjustments in the day light.

Do report back.

James

I always make my scope very slightly camera heavy in order for the gears to mesh without any play, other than that i spend quite a while making everything correctly balanced as i do with the rest of the setup. Yes i just signed up to a (localish) group so if all comes to fail i may have to seek there expert advice. I'm going to have a try getting at least a 2 star alignment tonight if it clears but i have to move my setup a good 50-60ft up the garden into what i call no-mans land as it's not a nice place in the pitch black ;) . Regarding the date and time i make sure i enter them to the accurate second, i select the 'no day light saving' now since the clocks went back. I'm not really sure if there is much cone error but i do try to get it correctly flat into the clamp on the mount. 

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jambouk

jambouk

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I suspect if you are doing only a one star alignment, being level may be important; if doing two or there it is probably less important i'd have thought. Having a scope with a large field of view and still having things not in the field of view suggests there is a relatively large error. At f/15 it doesn't take much to get something out of the field of view, but at f/5 or so and with a low mag eye piece there is something amiss.

You can check for cone error in your set up; you can do it in the daytime if there is something a long way away on a horizon (i suspect a mile away or more would be preferable (i'm plucking numbers out of the air)). There are lots of explanations online about checking for (and correcting) cone error.

I do suspect though doing a two star alignment really well will solve the problem.

The other thing you could do, is once you've done your star alignment, is to go around the area of interest (or all over your visible sky) and do some PAE corrections on the handset. GOTO a named star (or other object), centre the object in the field of view, then press and hold escape; the name of the object will flash on the handset, when it stops flashing press enter. It will then use that new position to update its map of the sky. I think it breaks the whole sky up into 88 areas (presumably one for each constellation) so you could pick a named star for each of the main constellations on show and improve your GoTO accuracy that way.

Don't wait till you are pulling your hair out, ask you new local astronomy friends for help. Having someone look at your tackle may result in an instant solution which isn't obvious to us in cyber world (or in nottingham)!

I do hope it gets solved quickly.

James

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RobertC

RobertC

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I suspect if you are doing only a one star alignment, being level may be important; if doing two or there it is probably less important i'd have thought. Having a scope with a large field of view and still having things not in the field of view suggests there is a relatively large error. At f/15 it doesn't take much to get something out of the field of view, but at f/5 or so and with a low mag eye piece there is something amiss.

You can check for cone error in your set up; you can do it in the daytime if there is something a long way away on a horizon (i suspect a mile away or more would be preferable (i'm plucking numbers out of the air)). There are lots of explanations online about checking for (and correcting) cone error.

I do suspect though doing a two star alignment really well will solve the problem.

The other thing you could do, is once you've done your star alignment, is to go around the area of interest (or all over your visible sky) and do some PAE corrections on the handset. GOTO a named star (or other object), centre the object in the field of view, then press and hold escape; the name of the object will flash on the handset, when it stops flashing press enter. It will then use that new position to update its map of the sky. I think it breaks the whole sky up into 88 areas (presumably one for each constellation) so you could pick a named star for each of the main constellations on show and improve your GoTO accuracy that way.

Don't wait till you are pulling your hair out, ask you new local astronomy friends for help. Having someone look at your tackle may result in an instant solution which isn't obvious to us in cyber world (or in nottingham)!

I do hope it gets solved quickly.

James

Shall do :) I'll give it a good go tonight as it looks like i will get around at least 2 hours of clear sky so i'll report back if it does clear, thanks !

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jambouk

jambouk

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Explore no mans land whilst it's still dark (clear anything you may trip over in the dark) and maybe mow an area if it's unmown currently, then less likely to loose anything if you drop something. I'd love a 60ft garden!

James

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RobertC

RobertC

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Explore no mans land whilst it's still dark (clear anything you may trip over in the dark) and maybe mow an area if it's unmown currently, then less likely to loose anything if you drop something. I'd love a 60ft garden!

James

It's all clear just in the dark it becomes rather scary on your own, got foxes and hedgehogs that wander around up there between the gardens. Still cloudy and rainy at the moment but it the weather report says it should clear after 6pm.

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JamesF

JamesF

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It's all clear just in the dark it becomes rather scary on your own, got foxes and hedgehogs that wander around up there between the gardens.

Take a radio or something to play music out with you.

I share my observing sessions with foxes, hedgehogs, badgers, pheasants, bats, frogs and some creatures I've not yet identified.  You get used to it after a while.  Almost needed a new pair of trousers the first time a badger crept up on me, mind.

James

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RobertC

RobertC

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Just having another go at trying to understand why my hour angle is 20 mins difference for my iphone app and my handset. My iphone is saying im -2 but i can't enter a negative into my handset, how do i simply enter that data for my longitude ?

These here is where i am stuck, i am entering into my handset 002 26 W    53 30 N and when i check on google maps i am in the correct area. So where is this 20 mins difference coming from ?

Iphone coords:

-2:26 W

53:30 N

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