View Full Version here: : EQMOD Stellarium and 3 star alignment help
20-01-2012, 11:04 PM
In the process of setting up my new EQ6 Pro mount and looking at different ways of controlling the mount with Stellarium through the Synscan controller, works ok and also Stellarium EQMOD ASCOM and Stellarium scope.
My Question is how do you perform a 3 star alignment when driving the mount without the Synscan controller in the loop but just driving with Stellarium or some other software through ASCOM and EQMOD? :help:
21-01-2012, 07:55 AM
You can't do it with Stellarium but I am not sure about EQMOD. A 2/3 star alignment is an algorithm calculated in software (or firmware) that finds the attitude of your system relative to the location of 2/3 stars.
You need to do this to align the telescope/mount before connecting to an external program.
21-01-2012, 08:30 PM
Yeh I wasn't sure how this would work.
Ken, I've never used EQMOD through the handset, but it's my understanding it becomes passive - effectively just part of the communication connection. EQMOD includes more sophisticated pointing modelling than the handset. You can do n-point sky models on either side of the meridian independently if need be (where "n" can be a very large number).
Basically you tell your planetarium software to point at an object, align it centrally in your scope (visually, by plate solving, or manually off camera image) then issue a "Sync" command from software (they all have various ways of doing this if you read the manual). In EQMOD you can choose how it reacts to a received Sync - e.g. if it adds it to the existing pointing model, or syncs the entire existing model.
Most people that start using EQMOD find it hard to go back to the handset.....:)
22-01-2012, 10:50 AM
I do rall reading about that but wasn't sure if it was what I needed for my situation as I don't have my setup fixed in one place (pack it up after each session) so I will re-read on that and how it all works.
After everything else I've read re EQMOD my aim was to do away with the handset and drive it all from the laptop.
Lots of reading to do and get your head around it all, new terms to understand the meaning of such as the one you have just mentioned (visually, by plate solving) but that's ok I enjoy new things and challenges.
Thanks for the info.
22-01-2012, 11:11 AM
The way I do it on my HEQ5 Pro is like Barry suggested....
First, I power the scope up and enter the parameters into the handset (basically the date and time as the other coords get stored in there), then perform a 2 or 3 star alignment.
When alignment is successful, I put the controller into Utility - PC direct mode, plug in the serial cable to the hand controller and start Stellarium Scope...
This starts EQMOD automatically and then spawns Stellarium. The control codes for the scope are CTRL-1 for GOTO object, CTRL-3 for SYNC and CTRL-5 for STOP.
As the scope is already polar aligned to my marks on the ground, and Stellarium is set for the same coordinates as the hand controller, time, date etc.....then TECHNICALLY, you dont need to have a star alignment done unless you want to go back to the hand controller to use it to GOTO and object....
Simply use F5 in Stellarium to bring up the search box, enter the object you want and then press the space bar to keep it centred on the screen and then press CTRL - 1. The PC should "BONG" to say it got the command and then the mount should slew to the object you selected.
Once it finishes, you should see the "scope" circle with a cross move on the screen to the object you have centred. Check through the eyepiece or camera that its in the centre of the FOV and then go back to Stellarium and press CTRL - 3 to SYNC Stellarium to the scope on the OBJECT you have selected.
What this does is fine tune the object centre to your scope visual centre and then when you subsequently goto another object, you should find the field of view is spot on to the centre of the thing you wish to look at.
Make sure that EQMOD has the Sidereal RATE clicked on (star button down the bottom) as mine for some reason as soon as I connect PC DIRECT mode, turns off Sidereal rate, so its not tracking the stars properly.
Then you can sit back, click on the screen and press CTRL-1 to goto any object in the Stellarium database and whooooooosh.....light speed to it via the scope.
Lots of fun when the kids are around and very convenient when imaging from a laptop as you can do quick test shots on the camera from your chair without having to punch in objects using the hand controller first.
I think from memory I didnt have to load any special plug ins into Stellarium for the scope bit to work or the reticule to appear, as I only recently downloaded Stellarium scope and Stellarium / EQ ASCOM etc, and it all just worked using the EQ5/EQ6 driver in EQ ASCOM.
Hope this helps, coz its fun to drive your scope like a tank commander from a comfy chair and watch it move like a gun turret.....
23-01-2012, 03:26 PM
I have installed Stellarium Scope but haven't set it up yet.
I'd been running the scope via the hand controller without Stellarium scope installed, it seems that the latest version has a driver for the EQ6 that doesn't use ASCOM but send its commands using the same protocols as the SynScan hand piece, (I think). Basically PC direct mode.
Yep the mount was doing all that but no Stell/scope installed but I hadn't tried the sync step .
Yeh that was all working ok as well.
I have a Shoestring (EQMOD2USB) cable that I bought at great expence when I picked up my new NEQ6 Pro mount and this will do away with the SynScan headpiece altogether, I think I should be able to still run Stellarium via Stell/scope using the EQMOD ASCOM interface and still do a star align from within that configuration hopefully. Got to look into that a bit more.
Now that sounds like where I want to be in the not too distant future :thumbsup:
Thanks for all that Chris,
It seems like there are a number of different configurations that will work with these latest versions of software, my aim is to get it to the least cumbersome setup that I can and maintain full functionality at the same time.
It's a great bit of kit and I don't mind the learning curve and the challenge of getting it working at its most optimum.
I have a desire to do some deep sky imaging and Carol is keen to see the outcome of it all as she is just amazed at what's out there. :eyepop:
You can look at all those stunning images from Hubble and the guys on here like Strongmanmike and Paul H just to mention a couple that do outstanding work but when you can take your camera from your own telescope and download the images that you yourself have just spent the evening taking it all seems so much more real to those around you and indeed yourself. So it's the challenge to do this and even on a low budget I won't mind if the images don't win prizes I be happy just to say I took those pictures.:D
I don't know how others feel about there work but I bet it makes them feel good to see their own pictures no matter how good or not so good it probably doesn't matter in the end it's just a lot of fun doing it.
Have a nice day and thanks.:thumbsup:
23-01-2012, 04:16 PM
Have you got the synscan controller (version 3.27). It sounds like you have. In this case you have no need for EQMOD
These devices have an align method for the mount using either a 2 or 3 star algorithm to help you get the mount aligned first with the polar axis and then with the stars as they are at the current location, date and time.
You can also align the polar axis using the inbuilt polar scope and then a fine tune with a drift alignment or you can use a much quicker method using PHD and a guide camera.
As long as you can get the polar alignment of the mount you can do the next step.
If your mount is already polar aligned you can bypass this step and just synchronise on a star.
Once the scope is aligned you can connect the synscan to the PC and if your program is Stellarium you can connect directly to it using the synscan/celestron nextstar driver. You won't need EQMOD or Stellarium scope or ASCOM if all you need to do is show the position of your scope in Stellarium and use the Stellarium Goto control.
If you wish to use a more complicated method you can use EQMOD via the synscan controller in the PC direct mode. This will remove the need for a an EQDIR cable.
To do this you will need ASCOM installed then EQMOD and Stellariumscope as well. But remember these are just extra programs to give you a PC based handbox controller that will duplicate most of the things that the Synscan controller already does.
In this way Stellarium can use ASCOM to communicate with EQMOD and thence the mount.
I have a HEQ5 Pro mount that has the synscan 3.27 and believe me it is more convenient to connect the PC to the synscan than using EQMOD which I can also use as well as a program of my own that can also control the mount from a PC
23-01-2012, 09:38 PM
Yes without booting it up I think it is V3.27 and yes I had been operating the mount exactly as you described above but it was or has been a bit misleading when you read all you can about the options you have without really knowing the time line of what you've been reading and what is the latest methods being employed.
So thinking EQMOD was what I needed to allow me to do all this better was the direction I was heading in although seeming more cumbersome it appeared to give you more ability to fine tune the mount for deep sky work.
Having said that I guess if you have polar alignment and you do your three star align, connect to your planetarium software for your visual goto control that's all you need aside from a good guide camera and phd and really I'm almost there with that setup, just got to get the guide camera working well and then it's fine tuning from there I guess.
Thanks for pointing that out Barry this is a bit of a steep learning curve but that's fine as there is always plenty of help around here.
Yes, it's worth emphasising no amount of star sync'ing is going to fix up bad polar alignment. Definitely worth mastering this essential skill, and probably best to have a go it a few different ways to see what works best for you (webcams, Alignmaster, drift, compass, polar scope, etc)
23-01-2012, 10:24 PM
The Synscan manual as supplied only partially applies to the 3.27 version. v3.27 has more options in the menus
This is a list of the menu items and some are not mentioned in the manual.
24-01-2012, 02:15 PM
Yes Rob I will most definately be ironing out that as my gear is packed away after each session.
Thanks again Barry and also Rob,
That printout does look diferent to whats in my book I got with the mount. I'll have time to check it out some more tonight.
Now that I have this I will be putting down some location pads in a couple of places as I have a 1/2 acre block with some rather tall trees so it depends on what area of sky I want to concentrate on for the night as to where I setup, north or south.
Didn't think about astro work when I planted the trees 17 years back. :D
24-01-2012, 03:07 PM
Re the Synscan manual. I hope they bring out an updated manual soon.
I went through mine using that page I generated and rewrote the sections refered to in the update from v3.11 pdf.
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