Topics

Abandoning eyepiece. How to align?


Pete
 

Both my OnStep telescopes work brilliantly.  I am now building my own observatory.  I have now got the 20 x 16 foot pad built.  I used 10 cu ft of concrete and it is over 12" thick in places.  The concrete pier goes down about 4 feet into the ground https://photos.app.goo.gl/RUC4YNg5qLFxFwDH8  Next step is to built the building and that will have to wait until Spring 2021.  

I am beginning to do more and more imaging and I am looking for a way to carry out OnStep alignment without using an eyepiece.  Actually I'd really like to do alignment entirely from my PC usng Windows 10 and ASCOM.  Is this possible?  If not, is it likely?

I have been told that one of the INDI / INDIGO OnStep driver variants can do this but I have not yet seen it.  Again, does it really exist?


Lloyd Simons
 

Yes. Its called plate solving. You let the software center the object. You dont have to align at all. ASTAP is free ware that is fast and works very well. Most image capture software have plate solving embedded (NINA, SGP etc). I’m not familiar with the linux apps but im sure its available on that platform as well.


"Guilherme Vênere
 

Not sure if this is what you're looking for, but if you can do plate solving, you don't really need the 3 star alignment from what i see. I don't have a fixed observatory, but once I polar align with Sharpcap, I usually goto to an object in the east and do a plate solving using NINA, and sync to OnStep. this initial goto don't even need to be too close to the object. After that my gotos are pretty much spot on. 

Now if you're talking about polar alignment, i can't help there but i guess you could use something like a Polemaster?  

guilherme

On Wed, Nov 18, 2020 at 3:44 PM Pete <pete.ingram@...> wrote:
Both my OnStep telescopes work brilliantly.  I am now building my own observatory.  I have now got the 20 x 16 foot pad built.  I used 10 cu ft of concrete and it is over 12" thick in places.  The concrete pier goes down about 4 feet into the ground https://photos.app.goo.gl/RUC4YNg5qLFxFwDH8  Next step is to built the building and that will have to wait until Spring 2021.  

I am beginning to do more and more imaging and I am looking for a way to carry out OnStep alignment without using an eyepiece.  Actually I'd really like to do alignment entirely from my PC usng Windows 10 and ASCOM.  Is this possible?  If not, is it likely?

I have been told that one of the INDI / INDIGO OnStep driver variants can do this but I have not yet seen it.  Again, does it really exist?


Khalid Baheyeldin
 

On Wed, Nov 18, 2020 at 06:44 PM, Pete wrote:
I am looking for a way to carry out OnStep alignment without using an eyepiece.  Actually I'd really like to do alignment entirely from my PC usng Windows 10 and ASCOM.  Is this possible?  If not, is it likely?
For me, I have been doing this for a couple of years.
Basically, you need anything that can do plate solving, and Sync on the solved coordinates.

What I use is KStars/Ekos/INDI to do all that. Installing the indexes for plate solving is a pain.
You have to find the indexes for your field of view + a certain factor, and they are huge files.
Once you do that, it works painlessly. I slew to a star, then say "Capture and Solve" with action "Sync on solution coordinates".
Repeat 3 times (or more) and the alignment is done ...

Of course, you have to do at least a rough focus before that. I do it using a Bahtinov mask, and often use Spiral Search to find that first bright star.

As a bonus, I can also center the object using plate solving. I slew to the object, then do a "Capture and Solve" with an action of "Slew to object". After the initial, it takes two more attempts to get me within 10 arc seconds of the center of the object.

I have been told that one of the INDI / INDIGO OnStep driver variants can do this but I have not yet seen it.  Again, does it really exist?
INDI alone will not do this. You need one layer above it that has image capture and plate solving.

If you are looking for an off the shelf solution, then take a look at Stellarmate.
It is basically a Raspberry Pi with KStars/Ekos/INDI preinstalled.

There are other Windows packages that can do plate solving. The key is to find if you can Sync on the solution coordinates, and you are good to go.


Howard Dutton
 

And often the point of having an observatory is that you can leave the mount/telescope setup.

Park OnStep after you have that really nice alignment done.  Power off and don't move anything.  Days etc. later power up, make sure date/time is correct, then Unpark and there is no need to align again.


Pete
 

Thanks to all who responded.  Plate solving is the obvious way.  I was actually looking for something that would allow me to to polar align my mount via the ZWO camera.  

@Khalid, I have looked at Stellarmate.  Several people I know use it.  Two of them mount the Pi directly to the telescope and then they connect the Pi  a WiFi AP and then VNC into the scope.  Everything each scope needs is onboard the OTA. Thus any PC or Mac just need VNC.

@Howard,  I am already using Park but, of course until my observatory is built I cannot make use of it properly.  It is true that with my pier and a building, I align once and then don't move it -- ever.  I understand that principle.  Just cannot get my head around never moving it again.

Finally, it sounds as if the OnStep ASCOM or its variants do not do what I asked about.  No problem.  I shall jut do plate solving and not touch the mount.  Helpful.  Thanks guys.    


Lloyd Simons
 

Polar alignment is a different matter. If you have a view of polaris you can use sharpcap pro and your camera. I can usually get polar aligned in 5-10 min and i don’t have a permanent setup. There are other options but sharp cap works so well I never really investigated others.


Dave Schwartz
 

SharpCap has polar alignment using a fairly narrow field of view camera and it has the required catalogs to solve near the pole built-in so nothing extra to download. I do it using my finderscope-mounted guide camera. You set your mount close to 90 degrees dec and RA rotated about 45 degrees to one side. Let it capture and solve that then rotate to 45 degrees on the other side. It will solve that, determine the center of rotation (where the RA axis is pointing) and then pick a star in that second field and guide you where to adjust the mount to the target where that star would have been had your polar alignment been perfect.

Basically does what a PoleMaster does using a camera you already own. The routine is only enabled in the subscription version but that's only 10 pounds per year. SharpCap is one of the best capture packages with native support for ZWO cameras so subscribing is a no-brainer.


On November 18, 2020 8:07:35 PM EST, Pete <pete.ingram@...> wrote:
Thanks to all who responded.  Plate solving is the obvious way.  I was actually looking for something that would allow me to to polar align my mount via the ZWO camera.  

@Khalid, I have looked at Stellarmate.  Several people I know use it.  Two of them mount the Pi directly to the telescope and then they connect the Pi  a WiFi AP and then VNC into the scope.  Everything each scope needs is onboard the OTA. Thus any PC or Mac just need VNC.

@Howard,  I am already using Park but, of course until my observatory is built I cannot make use of it properly.  It is true that with my pier and a building, I align once and then don't move it -- ever.  I understand that principle.  Just cannot get my head around never moving it again.

Finally, it sounds as if the OnStep ASCOM or its variants do not do what I asked about.  No problem.  I shall jut do plate solving and not touch the mount.  Helpful.  Thanks guys.    

--
Sent from my Android device with K-9 Mail. Please excuse my brevity.


Pete
 

I already use SharpCap and I also have a QHY PoleMaster Camera.  For mechanical mount alignment Polemaster is perfect.  To then mechanically align the telescope with the now aligned mount SharpCap is perfect.  All that remains is the OnStep alignment model which is what I was originally after.  The model needs to be re-established after each power cycle.  That is what I really need.  How can I do that without using the Smart Hand Controller and maybe an eyepiece too?


Mike Ahner
 

On Wed, Nov 18, 2020 at 08:36 PM, Pete wrote:
The model needs to be re-established after each power cycle.  That is what I really need.  How can I do that without using the Smart Hand Controller and maybe an eyepiece too?
After you have the mount permanently placed on the pier & polar aligned, star aligned: then using Park with OnStep means you won't need to redo an alignment.
But even without using Park, if your mount is on a permanent pier and accurately polar aligned, you don't really need to "do" any alignment in OnStep. You just power on with the mount in Home position, do a one star align and accept/sync to that star without ever looking thru the telescope. Because your mount hasn't moved and polar alignment is very precise and accurate, your first star should be dead center in the eyepiece.

Just to give yourself a reality check, Howard's planetarium program, Sky Planetarium is a well written, tightly integrated companion program to OnStep. SP does plate solving as part of the 3 (or more) star alignment procedure for all mounts, if you have a camera attached. Then it syncs OnStep and everything is good to go.
http://www.stellarjourney.com/index.php?r=site/software_sky

 I have used SP but I haven't tried plate solving with it since my dark site doesn't have Internet access yet.
I think all of these programs will do what you asked, it's challenging to understand sometimes with so much diversity and multiple solutions. You just have to find something that fits your work flow and thought processess.

-Mike


Pete
 

@Dave,  I have a subscription to SharpCap.  I bought it for the focusing and my Bhatinov Mask.  


 

I don't believe it's necessary to go through all that trouble. Whatever
program you are using to capture should have some kind of bulls eye over
lay. I use Nebulosity and it has one. Just use short one to two second
images to center the star or object in the center. PHD2 also has a drift
align tool that works pretty well for polar alignment. If you're not
using goto.

Rick
Tucson

____________________________________________________________
Sponsored by https://www.newser.com/?utm_source=part&utm_medium=uol&utm_campaign=rss_taglines_more

Lawsuit: As Workers Got COVID, Manager Started Betting Pool
http://thirdpartyoffers.juno.com/TGL3141/5fb67b178c9a07b175aa3st02vuc1
Adorable Owl Rescued From Less-Adorable Rockefeller Tree
http://thirdpartyoffers.juno.com/TGL3141/5fb67b17b170a7b175aa3st02vuc2
Bobby Brown Jr. Found Dead
http://thirdpartyoffers.juno.com/TGL3141/5fb67b17d4e567b175aa3st02vuc3


Pete
 

Rick,  Thanks for your reply.  I use Stellarium as a Planetarium program and SharpCap for imaging.  I am moving slowly to NINA as it does a lot more.  ASCOM 4.6 works well as a hub.  I think I need to learn more before I ask any more questions.  Howard has told me how I can solve the problem because he says that aligning the mount and the going to Park will survive a power cycle.  I am going to my pad tomorrow and I'll align the mount and then Park and see what happens.  Given that Howard wrote the code, I expect it to work.

What I really need is my building built and a working warm room.  Next year...


Pete
 

I finally got to my observatory pad and did some testing.  Obviously Park worked just as it should, as Howard said it would.  I did know that btw, just never used it but thanks anyway.

I really would still like to do an alignment without using the SHC or the Android app.  Can alignment be done via the wifi web page?  


Howard Dutton
 

On Tue, Nov 24, 2020 at 08:04 PM, Pete wrote:
Can alignment be done via the wifi web page?  
Yes.
1. Press the Align button on the Control page, say [3-Star].
2. Do a goto from somewhere (pick you planetarium program.)
3. Center the star on the Control page.
4. Press the Accept button on the Control page.
5. Repeat at 2. until all three stars are done.

On Windows my Sky Planetarium can do this too, including the ability to automate it using an ASCOM capable camera.


Khalid Baheyeldin
 

On Tue, Nov 24, 2020 at 11:04 PM, Pete wrote:
I really would still like to do an alignment without using the SHC or the Android app.  Can alignment be done via the wifi web page?
If you mean:
"Can alignment be done via the wifi web page only", then the answer is no, because the web interface lacks a catalog. Both the SHC and Android app do have such catalogs, as well as any planetarium that supports ASCOM.

If you mean:
"Can alignment be done via the wifi web page along with a planetarium", then Howard answered that question. You still need some other piece of software that has a catalog of stars and coordinates to slew then sync to.

You can sort of work around the limitation of the web interface having no catalog by uploading a handful of bright stars to OnStep to it (under Library), and update them every season or so, as they get lower and then under the horizon. That way, you can do the alignment solely from the web interface.

Having said all that, why are you bothering with alignment when you will have a fixed observatory? Spend an hour or two doing a drift align (maybe using a camera assisted procedure), and then from then on just Park and Unpark followed by Sync, and never worry about alignment again ...


Henk Aling
 

What kind of alignment?  What kind of camera?  I can give some advice about using a DSLR and polar alignment without using a computer. 

Point the scope at Polaris, rotate around RA at high speed 30 sec at 6400 ISO.  Eyeball the center of the tracks on the LCD and mark it (I use a piece of clear tape perforated with a needle).  It does not have to be dead center.  This takes some practice because that center can easily be outside the FOV.  Then take 2 second images to move the marked center towards NCP using the Alt/Az controls.  There is a 5-star asterism near the NCP that you can use that makes it easy to eyeball the NCP location on the LCD screen.  Check Stellarium for this. 

The result will be about 2' accurate, or better, as accurate as a pinhole and eyeballing in arc minutes depending on your scope.  Do the rotation in the same direction as when you are imaging because the axis of most mounts probably have about 2' play.

Once your polar alignment is some you can use a one star alignment.  For that to be exact, make sure you have no cone error.  That is equivalent to being able to get the center of rotation dead center in your camera.  If your calibration star is somewhat close to your target that should be accurate enough.


Pete
 

Hi Khalid,  Using the web page via WiFi and the PC / Stellarium plugged into OnStep via USB works just fine.  What I needed was a way to put OnStep into alignment mode 0 to build the model.  The web page did that.  I was able to make the mount move (in my sun room, no real stars yet) by using the web page to take the mount out of Home, use Stellarium to move to 3 stars (mount moved, Stellarium showed movement as usual.  I clicked Accept on the web page and the mount is now aligned.  If I had a camera on the telescope, I would have see my targets on the screen.  I could have used targets like Mizar (double), Albireo (red, blue), etc. to be sure I have the right targets in view.  

I need to try this at the observatory with real stars but, I think it is going to work.

Now what I need is to get my MiniPCB Mk.I to have ethernet so I can use a CAT-6 cable instead of WiFi.  I have seen several attempts in this forum but do any of them work?  Could I use an Ethernet adapter plugged into the Tx, Rx of the ESP01?  It looks like it might work.  VCC, GND, RST, Tx, Rx


Khalid Baheyeldin
 

On Wed, Nov 25, 2020 at 09:26 PM, Pete wrote:
Using the web page via WiFi and the PC / Stellarium plugged into OnStep via USB works just fine.
I know that would work, because there is a catalog of objects external to OnStep (e.g. the Android App).

The only logical reason that you use the web interface, but not the app, is that you are iPhone person,
so the object catalog has to somewhere else. If that is the case, then Sky Safari is an option too, so
you don't need a USB connection. Not an issue if this is a one time task (built a model, and store it
in OnStep so you can Park/Unpark). But consider it if you want to do this regularly.


John Petterson
 

On Wed, Nov 25, 2020 at 06:26 PM, Pete wrote:
Now what I need is to get my MiniPCB Mk.I to have ethernet so I can use a CAT-6 cable instead of WiFi.  I have seen several attempts in this forum but do any of them work?  Could I use an Ethernet adapter plugged into the Tx, Rx of the ESP01?  It looks like it might work.  VCC, GND, RST, Tx, Rx
Howard keeps telling me I am one of the few people using the Ethernet options, so I  will chime in.  Look at the Ethernet page on the Wiki.  I am using a Teensy 3.2 and W5500 adapter, it is solid and works well.  Uses only the TX and RX connection plus power and ground. The Teensy is 3.3V signals but 5V tolerant so it should just wire directly to anything.

John