ASIAM5 Polar Align

[admin]

Hi Jerry,

well, that's great news. I was pretty sure we'd get there in the end because if it really wasn't possible then we'd have heard the screaming from dozens of AM5 users long ago... It had to be something missing from the setup (or, just possibly, bad hardware). My suspicion is that the connection from the ASI mount app initialized something on the mount that was previously unset. Hopefully something you only have to do once...

A long career in software has put me in plenty of similar situations when you have to debug problems based on limited experience and without proper access to the system that was failing. As you know, there's a technique to it - learned by experience - of eliminating possibilites and narrowing down the areas where the problem might be.

Hope you get some clear sky soon - looking forward to seeing some pictures!

Robin

[jerry1]

Hey Robin,

Well, it does seem we eliminated quite a few possibilities before success was ours, but sometimes, that’s what it takes. I did try it again today to see if whatever it was that changed stayed changed, and everything just worked correctly the first time. After booting, I started with SharpCap rather than the AM5 app and pointed the scope to various targets. They all appeared to point the scope to where the targets were located. On the next clear evening here, I will do the real thing from polar alignment to moving to several targets and hope they are centered on the screen when the mount stops and settles. I’ll let you know how it goes.

And if I should ever experience the same kind of problem in the future, I at least know I can point to targets using the mount and still use SharpCap to capture my subframes – I won’t be dead in the water.

Thanks again!

Jerry

[jerry1]

Hi Robin,

We have finally had a couple of nights without clouds after a stretch of weeks with cloudy days (am definitely not liking global warming).

SharpCap appears to be properly pointing the scope to the selected target. I have polar aligned until the scope is under one minute of error on both axes and I receive the message that alignment is Excellent. However, when I switch to Live View, the target is off to the side or not on the screen. The mount is not tracking after it slews to the target – the stars are slowly moving. Is there a switch I need to turn tracking on in SharpCap?

I should have also tried target selection using the phone app for the AM5 mount itself, but spent all my time (90 minutes) to get it working in SharpCap. Because all this must be done without gloves, after 90 minutes my fingers were barely working, even with intervening time in my pockets. We are supposed to have some partly cloudy nights over the next few days and I’m hoping I will be able to see Polaris, align, and then slew to one or more targets not covered by clouds.

Thanks,

Jerry

[admin]

Hi Jerry,

so, it sounds as though you have the polar alignment nicely sorted now and we can pretty much ignore that as a source of errors. That means that the RA axis of your mount is correctly pointing at the pole... However, it still sounds as though the 'star alignment' of the mount isn't correct - that would mean the mount is confused about how far around east-west it is pointing (or how far north south). If that star alignment is wrong then all GOTO movements will be off by a fairly consistent amount.

To be honest, I don't know exactly how star alignment does/should work for the AM5 - what I can tell you is that you *should* be able to turn on tracking from within SharpCap using the 'tracking' button in the telescope control area - see https://docs.sharpcap.co.uk/4.1/#!3!Other%20Controls . You can also change the rate between sidereal (stars), soar and lunar.

Once tracking and the stars are staying still, if you are not far out then the 'plate solve and sync' button ought to put you on target - see https://docs.sharpcap.co.uk/4.1/#!2!Plate%20Solving . At least, it should tell you *how* far off you are and you can see if it is fairly consistent. You can increase the search radius for this tool from the default 15 degrees in the plate solving settings in the latest updates of SharpCap 4.1

cheers,

Robin

[jerry1]

Yes, alignment still takes some time in this cold weather, difficult without the ability to wear gloves during the process, but we got it working.

I did locate the Tracking button when I looked at the telescope controls again this morning. For whatever reason, I missed IT last night while trying to get everything working with cold hands. I also confirmed that turning it on in SharpCap also enables it on the ASI Mount popup screen – thanks!

This evening, I turned Tracking on and that solved my problem of moving stars. I used Stellarium to attempt to correlate how much the aimed scope is off from the actual target and it is close, but definitely not right on. I then tried to use the ASI Mount app on my phone, but for some reason, it was not displaying the “GoTo” button, so I was not able to initiate the slew function. This did work when I first installed in two or so months ago, but something has changed in those two months. I may have to uninstall and reinstall it.

I must admit that Celestron’s StarSense on its Alt/Az mount worked every time without these kinds of hassles. It did limit me to exposures of about a minute or so, but tracked well enough to take many stackable subframes. It also automatically polar aligned hands-free. I switched to the AM5 to gain the advantages of an EQ mount for long exposures. Do you think SharpCap will ever have the ability to polar align hands-free as long as the user can initially set the R/A fairly close to Polaris and the Dec fairly close also, perhaps a few degrees? Getting below one minute in each with freezing hands can be challenging, especially with the breeze we had this evening at temps in the mid 20s (-4C).

Finally, would you consider adding a “Home” button to the telescope controls? I have been trying to use ASCOM’s EQMOD/EQASCOM driver to Set Park to the Home position, but to no avail. Another alternative is if you could actually add the Set Park capability within SharpCap so we can set it where we like. But because I couldn’t set Park in ASCOM’s software, I presume you would need to do the same, but you likely know much more than I about their software.

Thanks again,

Jerry

[jerry1]

P.S. Plate Solve and Sync did not rectify the issue, so I presume that means the GoTo pointing is not close enough to the target?

[admin]

Hi,

did Plate solve and sync tell you that it failed to solve, or did it solve and then something else failed afterwards? It would be interesting to know. If it solves (or if you use 'Solve Only') from the tools menu, you can note down the co-ordinates of the solve position that are displayed in the green bar and then compare them to the mount readout to find out how far off you are.

I feel that I am struggling to give you good advice here because I am not familiar with the AM5 software myself - if you have a local astronomy society, you may be able to find someone else locally with an AM5 mount through them to get hands-on help and advice. I feel sure that either we are missing something important but subtle or there is some configuration problem.

As for finding home, there is a way via ASCOM to ask the mount to find the home position, but it is not implemented by all mounts. You can test it for your mount without me needing to change SharpCap - just do the following...

* Open camera, make sure mount is showing as connected
* Select scripting menu from the top, then 'Show Console'

A new window will appear with some text in it - it will say

Code: Select all

... other stuff ...
SharpCap scripting ready...
>>> 

There should be a cursor after the >>> - type exactly this and then press enter

Code: Select all

SharpCap.Mounts.SelectedMount.AscomMount.FindHome()

You may get an error if your mount cannot find the home position, or you may find that the mount moves to the home position. When I try this with EQMOD for my skywatcher mount, I get

Code: Select all

>>> SharpCap.Mounts.SelectedMount.AscomMount.FindHome()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
Exception: FindHome is not implemented in this driver.

That's telling me that my EQMOD driver doesn't support FindHome.

cheers,

Robin

[jerry1]

Good Morning Robin,

I understand the struggle you're experiencing and feel you've done an admirable job advising me across our communique's having no experience with the AM5. in fact, you've solved almost every problem and I greatly appreciate it. If it's ok with you, I will still ask an occasional question while I try to get more info, speak with the retailer who sold me the mount, and try to work this out, but I will refrain from being a burden. I will also share any useful info that I learn.

Here's one question:

My home is surrounded by trees. I believe I've been correctly using Polaris for alignment, but because of the trees, I cannot see the small dipper to confirm I'm at the end of the handle. I see what I believe is the pot portion of the large dipper and it does point to the star I believe is Polaris. But here is what I have been presuming through all these attempts is the most salient point:

I presume there is no way that SharpCap would never be able to plate solve during polar alignment if I had the wrong star. Isn't that correct?

Thanks,

Jerry

[admin]

Hi Jerry,

if SharpCap polar alignment plate solving is telling you that the star is polaris, then the chances of it being wrong are really tiny - it would have to see another group of stars that somehow managed to be similar enough to the stars around polaris for the code to be fooled. What's more, you would also have to be some way off the pole (more than about 7 degrees), otherwise the stars in view would be properly matched against the stars near the pole with a better match than the random one.

As a check, you can always get the stars around the pole on screen and run the 'Deep sky image annotation' function in SharpCap. Ask it to plate solve and check that the bright star you think is Polaris gets highlighted as Polaris/Alpha UMi. For that sort of plate solving, SharpCap does a statistical calculation of how likely a random false match would be - it will only use results where the calculated chance of a random match is less than 1 in 10 billion.

Good luck with getting it all sorted!

cheers,

Robin

[oopfan]

Jerry,

If you have a smartphone (I have an iPhone 12) go to the App Store and search for "ephemeris". The app you are looking for is "Ephemeris: Moon and Sun Seeker" by Vito Technology. It uses the phone's built-in hardware to tell where the Sun and Moon are in real-time. It uses Augmented Reality (AR), much like a fighter pilot's heads-up display, to draw an equatorial grid superimposed on the output of the back-facing camera. Be sure to click the button for the equatorial grid and not the horizontal grid. Like you, I have lots of trees. With this app I can pinpoint Polaris between the trees. The app is inexpensive to purchase outright although there is a monthly rental option. I'm not sure if they have an Android work-alike but I would be surprised if they didn't.

Brian