HEQ5 Pro - Polar Alignment

[callingrohit (Vivek)]

Hi Community,

I have recently purchased an HEQ5 Pro and the guide is not helpful in regards to alignment.

Could anyone kindly guide me towards a website or video that will assist in aligning - mount and synscan ?

I think for synscan - 3 star alignment should be an easy go.

However the alignment of the mount is somewhat confusing.

[Poita (Peter)]

There is a guide by one of our members here:
http://brendanmitchell.net/wp-conten...-a-Synta1.docx

[RobF (Rob)]

Remember of course there are 2 separate but related things you're trying to pull off here - polar alignment then software star alignment. A question - do you need it spot on for photography, or just trying to learn how to tame set up for visual?
I always struggled to get my Heq5 pointing reliably for visual until I'd learned to get it PA'd really well for astrophotography must admit.

[callingrohit (Vivek)]

Thank you peter for the link and rob for your comments.

I essentially want to achieve alignment for photography but I know its not gonna happen overnight. So I have gathered all my patience for this one.

The thing is there are so many different ways of achieving it and I'm confused.

But to start off, I may follow this to just see how it works out - http://www.geologynet.com/astronomy/polar.htm.

Also when its written to point the mount to true south, is it referring to moving the North Label on one of the tripod legs towards true south ?

The software alignment takes care of the visual alignment.

Have I understood this correctly ?

[RobF (Rob)]

If you can see the South C Pole from your site it's probably worth learning how to align and use your polar scope. It does mean quite a bit of squinting and grovelling in the dirt though.

If you'll be doing astrophotography then drift aligning through a camera with a refresh rate of about 1 frame/sec is hard to beat and a 2nd technique really worth mastering. Do you have a guiding camera at the moment? If not it really would be worth having one for this alone, but also for some planetary fun (there was a Toucam with 1.25" adaptor going for $70 including postage from memory recently in the classifieds). The great thing about drift aligning is it teaches you the how and why about getting you altitude and azimuth adjusted well. As you get closer to perfect the drift is hard to see though, which makes doing it by eye time consuming and not much fun. I guess I'm assuming you'll have access to a laptop or PC at the scope though mind you.....

Yes, star alignments are just software correcting for mount inaccuracies and polar alignment.

[callingrohit (Vivek)]

Thanks for replying rob.

Right now I don't have a guiding camera or scope although I do have the phillips toucam which I have used. But doesn't one need another scope with a camera dedicated for autoguiding ?

I have a hitechastro adaptor which can control my mount via the computer. I may try to use this using stellarium.

[RobF (Rob)]

If you have a toucam and laptop then just whack the webcam in the main scope, then drift align according to:

http://www.iceinspace.com.au/63-544-0-0-1-0.html

I used K3CCDTools V1 freeware for ages, but now just turn off tracking in my guiding software and monitor the graph - but that's another story.....

Don't be too put off by the all the variations on how to get Polar aligned. If you can, trying a few of them for yourself is a great learning experience from the backyard. The goal is to get something you're fine with so when you go to a dark sky site you don't spend all night swearing. BTW, don't be afraid to mark out where you have the scope and put some marks on the mount if need be so you can get back to that spot. I can get away with a quick check (or none if I'm trying my luck) when pulling down and putting up again another night from home, but do have the luxury of tiles to set up on and mark. There are plenty of people here to help more if need be.

[Tandum (Robin)]

I had a lump of 4x4 lying in the back yard for ages. It was aligned south so I could just put the rear mount legs against it and I was pointing south

[Visionoz (Bill)]

Originally Posted by callingrohit

...
But to start off, I may follow this to just see how it works out - http://www.geologynet.com/astronomy/polar.htm.

Also when its written to point the mount to true south, is it referring to moving the North Label on one of the tripod legs towards true south ?

The software alignment takes care of the visual alignment.

Have I understood this correctly ?

Yep, you've got it right - the tripod leg marked "North" is the leg you want to point roughly towards true south - this is correct on the premise that the leg is also aligned to where your scope is pointing to when it is mounted

HTH
Cheers
Bill

[callingrohit (Vivek)]

Thank you Rob, Bill and Robin for your replies.

Yesterday even though it was getting cloudy I thought to just try it out to get an experience out of it as I was unpacking a brand new heq5 pro.

Anyways got it all balanced between the weights and the scope.

Got hitecastro working on my laptop and could control the scope via using stellarium scope, eqmod ascom & stellarium.

I was able to get the mount to slew where ever I pointed it on the stellarium.

However, the accuracy was zero. I pointed the north leg of the tripod to true south. I used my android based compass, had a setting change to true north and I hope this showed me the true south. (I think this assumption could be wrong).

Anyways done that and I expected that if I point to Jupiter in the east (easily visible from my backyard), the telescope will slew in east somewhere and not to exactly where Jupiter should be (between the clouds I could see its exact location and ofcourse I had stellarium).

But the telescope started slewing into the south direction and stopped - stellarium showed - its on jupiter !!!

So I'm a bit baffled as to what this indicates. I also tried various trial and error methods but the direction which I would predict for the telescope would always be wrong once I selected a target on stellarium in a known direction ?

Any clues guys ?

Sorry for the long post but I wanted to provide as much info as possible to get the correct advice. Its sort of overwhelming with the amount of info out there.

Thanks

[RobF (Rob)]

What longitude and lat set up in the handcontroller and PC?
Is time zone set to GMT + 10hrs?

[callingrohit (Vivek)]

Lat on scope was set to 27 deg

Please don't mind but I can't give you my exact lat and lon as it can be used to find my location. However what I can tell you is lat was in the range of 27 deg and lon in the range of 153. I live around Brisbane.

Timezone was correct too. I wanted to use alignmaster but their registration key delivery system is too slow so I couldn't use the software. Still waiting for a key to be I guess manually generated and emailed.

The exact location lat and lon was found by using the following online tools -
http://universimmedia.pagesperso-orange.fr/geo/loc.htm
http://www.findlatitudeandlongitude.com/

Is my assumption regarding the true south correct ?

[RobF (Rob)]

I should have been clearer - really just asking for you to check that Long is East and lat South, and time GMT+10

[naskies (Dave)]

Hi,

I picked up an NEQ6 a couple of months ago and can sympathise with your frustrations. I've tried various methods for polar alignment, but the easiest method for me by far is to drift align using the PHD guiding software. (There are lots of online how-to guides.)

With 0.2 sec exposures on bright stars (i.e. 5 frames per second), the feedback is virtually instantaneous. I can make a change to the mount's alignment knobs and PHD will tell me within seconds whether it's an improvement. If I want more accurate alignment, I just wait a bit longer - HEAPS faster than doing it through an eyepiece.

Best part of all - I don't worry about figuring out which way the alignment star drifts versus what direction to make the change. When I get PHD started, I just make a BIG change to polar alignment and see how it affects the guiding accuracy graph (e.g. rotate mount to the left = moves the PHD graph/line up) and just go by that.

I still don't know how to polar align by looking through the polar scope or by drift aligning without PHD... but several minute long exposures haven't been a problem at all


Cheers,

Dave


Edit: are you able to successfully three-star align the mount using the SynScan hand controller only?

[callingrohit (Vivek)]

Yup it was set correctly S 27 and E 153 as lat and lon respectively.

Stellarium also asked for altitude in and it specified 38m as soon as I entered my exact coordinates. If I entered Brisbane as location it showed 47m as altitude.

[callingrohit (Vivek)]

Thanks for your encouragement dave. I haven't tried the star alignment as it was very cloudy and I was just giving my new scope a shot to get a feel of it. Also wanted to make sure I setup the softwares to control it.

I will give PHD a try next weekend. I have a philips SPC900N webcam which I will fit into the scope using an eyepiece projection unit with 25 mm EP to get a larger FOV.

If you have any links handy in relation to how to use PHD for alignment, do share them.

Thanks

[naskies (Dave)]

Originally Posted by callingrohit

Thanks for your encouragement dave. I haven't tried the star alignment as it was very cloudy and I was just giving my new scope a shot to get a feel of it. Also wanted to make sure I setup the softwares to control it.

I might be misunderstanding you... but did you run a successful star alignment routine through EQMOD when you were trying to slew to Jupiter via Stellarium? As others have mentioned, polar alignment and software star alignment are two different things.

Polar alignment is what keeps the stars in your eyepiece/camera stationary over time (i.e. it's what you need for astrophotography). You do this by physically turning the mount left/right and rotating it up/down ("drift alignment" tells you which direction and by how much to move it).

Software star alignment is used to slew to an object accurately (i.e. what you needed to slew to Jupiter). This is done by getting the software to point at a star, and then you make corrections to centre it using the hand controller or laptop, and then repeat a number of times. This doesn't involve physically touching the mount.

Before I discovered PHD drift alignment, I had very rough polar alignment but could still software align reasonably okay. I could accurately slew to objects within a few minutes of doing the alignment, but it would then rapidly become inaccurate.

(Sorry if you knew this already... it caused me a lot of grief in the early days until I figured out the difference!)

I will give PHD a try next weekend. I have a philips SPC900N webcam which I will fit into the scope using an eyepiece projection unit with 25 mm EP to get a larger FOV.

If you have any links handy in relation to how to use PHD for alignment, do share them.

I had another quick look on Google - if you search for "drift alignment using phd graphs" (including the quote marks) one of the top matches should be a PowerPoint presentation with step-by-step instructions and screen shots.

Good luck!

[Visionoz (Bill)]

Originally Posted by callingrohit

Yup it was set correctly S 27 and E 153 as lat and lon respectively.

Stellarium also asked for altitude in and it specified 38m as soon as I entered my exact coordinates. If I entered Brisbane as location it showed 47m as altitude.

If you had pointed the mount in the "correct direction" ie due south (don't worry about being too accurate here) - you know, as much as true south is, based on your own method of finding it, eg: with a compass etc, then in general terms when you use the hand-controller to do your 1, 2 or 3-star alignments when prompted by the SynScan controller you should be able to get the slewing working quite OK-ish and accurately ONLY AFTER it's aligned!!

The first star offered depends on whether the setup menu for "alignment stars" were based on alpha sort order or by brightness - if you recognise say Canopus then use that as the first one for eg - the mount will slew to where it thinks Canopus is and then this is when you have to use the 4 arrows of the handcontroller to "center" Canopus to the center of the eyepiece manually (it may be quite off the center of your eyepiece view) - you then proceed to the next alignment star (assuming you chose the 2-star alignment option) and repeat the "centering" process and when that's all done you should be able to slew to any object quite accurately

Sorry to be so specific with the above explanation but just to make sure that you're ontrack with how it's being done

You did ask why Stellarium showed that you're spot on your selected object but actually the mount is not pointing in the correct location - reason is because you did not do the star alignment yet - hence Stellarium software thinks it's where it should be BUT it is not correlated to the mount thinking where it actually is because the mount wasn't aligned yet! I may be wrong in this but I'm confident that's the real cause - I been there and done that before!!

If you think about it this way: Stellarium knows where the SCP is, the mount has been star aligned so "knows where" the SCP is and therefore when you slew correctly to say Jupiter - the movement is "synchronised" with Stellarium showing where Jupiter is - if the mount is not aligned then the two results will have no correlation to each other

BTW naskies suggestion is workable too and is useful only when you need very close/accurate polar alignment

HTH
Cheers
Bill

[Visionoz (Bill)]

Oh! BTW I hope you've read this article - http://www.iceinspace.com.au/63-498-0-0-1-0.html

It will assist you to work thru the basic set up of the GEM and rough alignment of the mount

HTH
Cheers
Bill

[Ross G]

Hi,

How are you physically setting the correct latitude on your mount?

Good luck.

Ross.