Starsense on AVX mount

[Beardy30]

Forgive me if this is daft question but how does a starsense work on a celestron AVX eq mount ..does it do it automatically without the need to manually align to Polaris ? 

Edited February 18, 2021 by Beardy30

[Moodtastic]

Starsense does work with AVX. If you are doing visual then a rough polar alignment (I had the polarscope on mine) is all that is needed. Once polar aligned just set it off to do its thing and you will have pretty accurate go to.

[jefrs]

I have StarSense from my 130SLT on which it is very good and takes only a few minutes, and which I have just fitted to AVX and waiting for clear sky to test.

Reading the StarSense manual the sequence is to AutoAlign first (no I do not know why as it is going to need Auto-aligning again after polar align is shifted) then Polar Align upon which StarSense will give instructions on how far to Manually move the mount up or down, left or right, to align Polaris. Note - Manually using the big screws, not the motor controls.

The StarSense has to be calibrated to your OTA, it does not know where your OTA is pointed. To aid doing this I first align RACI crosshairs to the centre of the OTA, which can be done in daylight. This process is described in the StarSense manual - StarSense will move to a star and tell you to align the OTA centre to the star and save the position. (my OTA will be loaded with a camera and I cannot use a red dot, RACI is easier)

The StarSense /must/ be focussed. Which is not a lot of fun as there is no camera output. So you have to run alignment and iteratively move the focus in ever decreasing turns back and forth to gain maximum star numbers during plate solving. This can take all night but once done is done. When done StarSense will align very quickly, a few minutes.  If it takes longer it needs focussing.

Once the first Auto-alignment is done StarSense needs to ba calibrated per the manual. StarSense will also plate solve during the night to aid GoTo alignment.  It is a GoTo aid and will allow you to hit the mark accurately. StarSense also likes additional calibration points, and to know which areas it should not try to use (like the side of the house). What it is not is a star guider. It takes the hard work out of aligning a computerised mount.

StarSense is very easy to use in practice, you just hit the button to align. Once it has been set up, that's is. It is worth having; the mount will not work without alignment, StarSense does that for you. But you must read and understand the manual first, and the manual is written backwards and sideways.

[jefrs]

On 18/02/2021 at 21:36, Moodtastic said:

Starsense does work with AVX. If you are doing visual then a rough polar alignment (I had the polarscope on mine) is all that is needed. Once polar aligned just set it off to do its thing and you will have pretty accurate go to.

Yes it does work on the AVX. The StarSense camera and controller can support several different  mounts. StarSense is available for Celestron and Sky-Watcher but they are different flavours  and  are not interchangeable, (N.B.!!) 

To align the AVX by the book - read the book of words (it is very tedious)

Fist set up the mount pointing northwards (I'm North but your pole may differ).  Level the scope mount with a bubble, important! Roughly set alt and dec, I do mean alt & dec the mount screws - so the (optional polar scope ) tube is aimed somewhere near Polaris. See Polaris through the tube if your back will take it. I bought the polar scope, and a right-angle viewer, it is not needed.

Enter time and date. Do set Real Time Clock (RTC) so it will remember in future. Set your exact lat & lon location.  Time and date must be correct, if it will not hold correct time and date  and/or your location change the backup CR2032 battery. 
Always check the time before the off, the backup clock is as accurate as a cheap watch. If you use WiFi the interweb time servers synchronise to NIST so they should be accurate.  (Although NPL (UK) has the realisation of UTC and offers a time server too) .  You can select your time server on a computer but Microsoft gets its shorts in a bunch if it doesn't use their own)

Now Align - Auto Align. It will slew to two stars and then want to Calibrate on up to a further four.  Follow the instructions on the controller.   It will slew to a star, align the OTA to that star. It will then slew to a second star, align the OTA to that. Now  it will want to Calibrate. It will display a list of stars that are up. Pick one you like, it will slew to that, follow instructions and centre on that. Repeat with three more.

Now we want to do the Polar Align aka All-Star Polar Align. Press Align, find the Polar Align, select.  We are presented with a list of stars. We want one on the meridian, due south and fairly high, Rigel would be nice.  Select your star. It will slew to it. Follow the instructions on the hand set! First it wants you to centre the OTA to the star. Now it will slew off to where it thinks it should be. It will tell you to move the alt & dec screws to centre the star again.  Finish up. Polar Alignment done.

But now it will want you to do another Align and Calibrate. This time however your corrections will be very small. The whole Align and Calibrate, centring the OTA on the star is boring! This is what the Star-Seance  does for you whilst you make a hot drink.

Setting up the StarSense though  - read the StarSense book! First time is not just plug it in and run it. First time is Run it then Calibrate a few stars then run it again.  

Imo the Align and Calibrate instructions in the manual(s) are not written in a straight-forwards "do this" manner.  Please make sure you read them forwards, backwards and sideways. The actual processes are nowhere near as difficult as the interminable instructions imply.  

The StarSense takes the boring bit out of the Align and Calibrate. Especially with a stand-alone mount. If you cave cameras and computer there are other software methods of automating the job.    

WiFi - if you have WiFi (who doesn't?) we can use the Celestron CPWI to run the StarSense Auto-Align then slew the OTA to target. Again there are other computerised methods available. 

WiFi Sky-Portal v2. Issue as yet unresolved, Celestron tech are helpful but have yet to come up with a solution. This device is a WiFi dongle. The V2 is much more powerful than the V1.  First you connect to iPad/iPhone then tell it to connect to your home router and connect to Laptop. It will support more than one mount. You can run Celestron CPWI or other planetariums (I've not tested) to run StarSense Ailgn etc, and slew the mount about. using the planetarium, 
Until your ISP gives you a nice new router!
If you change the router name it will not connect to the new one and <rude-word> thing plays dumb insolence. It becomes utterly useless, I had to buy another.
The V1 (which is not powerful enough for the range needed) has a reset hole, nice. The V2 does not (and there is no button inside 'cos I took it apart to find it). What you should do /before/ they change your router is switch the Sky-Portal back to iPad from the computer(!) and then delete the old router name from it, then give it the new router name from the iPhone.

[ScouseSpaceCadet]

I was considering replacing my AVX with an alt-az mount but then the cheap option of a Starsense popped into my head. However reading all this has put me off!

I assume if you take the kit to a star camp for instance, then the whole laborious auto polar align and calibration needs to be done again? 

For visual it's likely way faster just to look through the polar scope, adjust and then pick two or three stars to align to. 🙄

 

[Shimrod]

3 hours ago, ScouseSpaceCadet said:

I was considering replacing my AVX with an alt-az mount but then the cheap option of a Starsense popped into my head. However reading all this has put me off!

I assume if you take the kit to a star camp for instance, then the whole laborious auto polar align and calibration needs to be done again? 

For visual it's likely way faster just to look through the polar scope, adjust and then pick two or three stars to align to. 🙄

 

You only need to calibrate once for the OTA. You would re-calibrate only if you move the starsense camera from one OTA to another (I use mine on both an 8" Edge and 80ed). Calibration only takes a few seconds. You need to roughly polar align but it does not have to be accurate for visual use.

After that you start the auto align and leave it to do it's thing - it take a couple of minutes. I use that time to finish bringing out eyepieces and what-not. I find it is generally good enough for me to move the telescope to a target and have it in field of view.

I use a iPolar to perform my polar alignment so although the Starsense has a polar align feature I have never used it.

The starsense is handy, especially if just doing visual because it is a nice, self-contained unit with no need for a laptop or tablet. However, given the cost of a the Starsense (£350), the ipolar (£212) and a guide camera (£170) if I was buying these now I would probably consider something like the StarAid Revolution (£800) as a neater, self-contained package.

 

Edit: I should add if you check the forum you'll find quite mixed views on the Starsense camera. I will say sometimes it does seem to have a bit of a 'funny' and I have to repeat the alignment process a second time.

Edited February 17, 2023 by Shimrod