NexStar 6se and SkySafari and SkyPortal

[yorkpf]

I have a relatively simple setup: a Celestron NexStar 6se (about 10 years old), coupled with a Canon EOS 700D DSLR.

I live in a home unit in Brisbane, Australia (southern hemisphere) and the balcony is really too small to accommodate the Edge HD and an equatorial mount. However, the NexStar with its alt-azimuth fork mount is a good fit, even though its tracking and pointing ability may be somewhat underdone for celestrial photography. Anyway, needs must …

My study is right next door to the balcony, so I plan to drive the whole setup “remotely” (including the camera) from the comfort of the indoors.

I have a Celestron Sky Portal WiFi module plugged into the scope’s AUX port, and am running SkySafari 6 Pro to drive the NexStar. I am just using USB cables for the camera, focuser etc …

I’m using a MacBook Pro for all of this: SkySafari runs on the Mac OK as does AstroDSLR (from CloudMakers) for image capture. I don’t particularly want to get involved with Windows, although I can run Windows 10 using Parallels.

I have run into a certain amount of trouble in trying to make the NexStar-SkyPortal-SkySafari setup work properly.

I have set up the SkyPortal to run in WLAN (access Point) mode. When I kick off SkySafari 6 and turn on the NexStar, I seem to be able to Connect OK. In fact, by using SkySafari’s scope Control Panel, I can make the scope move left, right, up and down etc. Quite promising, really …

By this time, I will have checked that my Location is correctly set in the NexStar mount using the hand controller (HC) on the scope and also that the date and time are correct. Typically, the scope will also be horizontal and pointing more or less due South.

However, the trouble really starts when I try to Align the scope. Typically the screen in SkySafari (the skychart?) shows the southern horizon and the sky up to the zenith, but there is usually no sign of the Field-of-View (FOV) display – the small set of concentric circles that is supposed to show where the scope is pointing. By hunting around, I can usually find it somehere around the the Northern horizon (about 180 degrees from where it is supposed to be)!

If I try to move the FOV display so that it is facing South (using the “ direction buttons” in SkySafari), I can sometimes do it, but the actual scope by then is pointing North! If I try to just go ahead with the Alignment by choosing an alignment star in the South, SkySafari claims that the scope is too far from the alignment point and will not continue with the alignment!

Often too, the “direction buttons” in SkySafari will send the scope in quite the wrong direction, even though the buttons on the “real” hand controller usually continue working OK.

It sounds like a southern versus northern hemisphere type of problem, but there seems to be nowhere on the scope or the SkyPortal or in SkySafari 6 itself where the hemisphere can be chosen.

Incidentally, I also have an Apple iPad with SkySafari installed, and the whole thing still misbehaves in the same way …

I am therefore interested in hearing from anyone who has managed to make this setup work, or has any insight at all into what the trouble might be or how best to proceed.

Thank you in advance,
Paul

[AndyG]

G'day Paul,

Without going into specifics, I believe you should pay attention to the following:

1. Hand control is not needed. Disconnect it, and make sure the mount is started without the HC present. The pointing data/tracking/motorcontrol/etc will be handled by SkySafari. Skysafari and the Wifi dongle will tell the mount everything it needs to know.

2. Make sure the current location, time and Timezone is set in Skysafari. This is easiest with your iPad, as it has a GPS and time data made available to skysafari. Presuming the MacBook has no GPS available, this must be done manually.

3. Manually move the scope to a known object, centre in the eyepiece, and then select the same object in SkySafari, then click "Align".

4. Repeat this a few times, with objects well separated throughout the sky, and you will have a good goto basis.

5. Look at "Slewing and Aligning":

https://skysafariastronomy.com/support/manual/manual.shtml#scope_control.html

6. Be excellent to Yourself.

[yorkpf]

Thanks Andy for your advice. I will follow up all of that.

But a question re your #3: When you say "manually move the scope", how do you do this without the HC? Do you mean physically "force" it by hand or do you mean use the control buttons in SkySafari?

Paul

[AndyG]

Hi Paul,
Indeed, move the scope via the control buttons in SkySafari. The Scope will then physically move to what you wish to observe. Once it's dead centre on a known object, you can find that object in SkySafari, select it, then hit "Align". You have then told the scope and software "it is where it is".

When aligning, feel free to use higher power EPs and careful movements to make exact alignments. Also, be sure the mount is dead level. This last few things I'm sure you know, but for the benefit of those googling later...

[yorkpf]

Andy

Amazing! Although I am fiddling around in daylight, I can already see that that is going to work quite well. Of course, I need to try all that at night.

I can't thank you enough for your advice and rapid reply.

Regards: Paul

[yorkpf]

Just one more question:

I have been working in detail through the SkySafari 6 Pro "manual" and was wondering about the HIBERNATE function. Presumably it works pretty much as described and also as described in the NexStar manual - ie. it saves its alignment data before powering down, so that if you WAKE UP the scope, it is still aligned?

So does it make sense, if you never move your mount, to ALWAYS hibernate before powering off?

Does the mount / SkySafari also retain the location and date / time when hibernating?

If you WAKE UP the scope (say) three nights or a week later, will it still be aligned? That is, the aligment doesn't "age" in any sense?

Regards: Paul

[AndyG]

Hello Paul,

I've not done any of what you've described in practice. I do own a Celestron Astrofi mount. This is essentially an old SLT mount with the wifi dongle stuck inside it. I say this, as I have an SLT also, and they look the same.

My impression (not claim to fact), is that the hibernation simply parks the scope in a neutral direction, and ceases the motor tracking. Meanwhile all the clock and location data is maintained. This means upon wakeup, a goto can be performed instantly.

Once the mount is powered down, the link to SkySafari would be lost, and all clock/location data is also gone. I'm not sure how you'd go trying to reconnect the mount and maintain this alignment, even if the SkySafari instance remained alive the whole time.

This instance of Hibernation is good to save the motors running all day, and more importantly, the scope hitting something as it tracks under the horizon as the day moves on. In any case, the mount, and the "brains" (iPad or laptop) need to be connected and left on. If done, with a very good initial alignment, you could indeed resume after some hours, days, etc.

It would be good to get some others' opinion on this. Especially in the realm of how Skysafari works if pushed into the background on the iPad, or iPad put to sleep, etc. The "Brains" does need to pick up where it left off for Hibernation to work. Hope this helps :)

[yorkpf]

Thanks Andy, for your response.

What you say does make sense, but one thing I can do is simply "suck it and see". I will try that sometime.

Paul