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Celestron Starsense Autoalign Only Stars Center

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#1 localhost

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Posted 14 November 2017 - 03:21 PM

Hey everyone I managed to get a Celestron Starsense Autoalign, did everything right I'm pretty sure.

 

For some reason only stars will center in the eyepiece anything that isn't a star will be in the eyepiece field of view using a 40mm eyepiece.

 

I've tried factory resetting the starsense controller didn't appear to work either.

 

Did double check that date / time and location were correct.

 

The telescope I've been using is a Celestron Nexstar 5SE I did upgrade the firmware for the starsense camera and the starsense hand controller about 5 days ago.

 

I also wanna mention for some reason the Celestron SkySync GPS I guess is extremely slow or when used with the starsense but the SkySync GPS is fine if I use it with the 5SE only but when it comes to connecting the AUX cable from the Starsense camera into the GPS AUX port doesn't update I did check to make sure that the GPS was detected and had a check mark under then time / loc for starsense controller

 

Was told to connect the GPS to the Starsense hand controller

 

I was told that it's considered correct that as long as the object is in the field of the eyepiece. I just don't get why all stars are centered just not anything that's not a star.

 

So I wanted to see if any of you with a Starsense have this some thing out come only stars center in the eyepiece and anything not a star isn't centered.

 



#2 Michael_Swanson

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Posted 14 November 2017 - 06:05 PM

Hi,

 

After a successful StarSense alignment, have you performed the Camera Calibration using the hand control menu?  This is a one-time requirement, providing you don't rotate the camera in the mounting ring or change the mounting location of the camera.  The purpose of the calibration is to inform the system of the location of the center of the field of view in main optical tube as compared to the imaging sensor in the StarSense camera.



#3 lenrabinowitz

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Posted 14 November 2017 - 06:13 PM

Mine does this also.  Never considered it a problem.  It depends on how accurate your alignment is.  Things like planets move also. It helps to use a high power eyepiece for center calibration.



#4 Noah4x4

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Posted 14 November 2017 - 07:07 PM

Some objects are notorious; example Mars has a retrograde movement, but most should be centred suffice to be inside the FOV of a medium magnification EP. 

 

However, as Len says, use a high power eyepiece to do the centre calibration (ideally a reticle Cross Hair EP). But also add (up to) ten additional alignment points. These act like the SYNC command that improvesvaccuracy around a chosen star, but StarSense offers ten. Spread these across the sky and seasons and enjoy much greater GoTo accuracy beyond the areas limited by the original Starsense plate solving. 


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Posted 14 November 2017 - 07:43 PM

Hi,

 

After a successful StarSense alignment, have you performed the Camera Calibration using the hand control menu?  This is a one-time requirement, providing you don't rotate the camera in the mounting ring or change the mounting location of the camera.  The purpose of the calibration is to inform the system of the location of the center of the field of view in main optical tube as compared to the imaging sensor in the StarSense camera.

Sure have the first day I used the starsense I made the mistake of not doing the calibration step.

I've do the starsense auto when it finished it said alignment complete, pressed back to get to the Starsense Ready screen pressed on Stars button named stars used Vega mount slewed to Vega but like I was told it's normal for the star to not be in the eyepiece, didn't adjust or slew to center the star after the mount slewed to where Vega was with Vega not in the field of view of a 40mm eyepiece  pressed back twice got to the Starsense Ready screen, went to menu located Starsense picked Calibrate shows the center numbers or something and to press enter then it says to center Vega so starting out I use a 40mm eyepiece get Vega centered in a 40mm eyepiece press enter then says to do a fine center so I switch to a 10mm eyepiece center the star in the 10mm eyepiece, press align controller says acquiring image then says solution found accept the new center tells me a realignment is needed press enter takes me back to the Starsense Ready screen pick Starsense Auto it does the auto align, when finished it says alignment complete.

 

Slew to a Andromeda it's off  from the center close the edge of the eyepiece field of view with a 40mm eyepiece, slew to say  the Pleiades they fit nicely in the center of the eyepiece maybe  not "centered" but they at least fill the field of view of the 40mm eyepiece.

 

Slew to Capella centers fine in the 40mm eyepiece all stars are centered in a 40mm eyepiece anything not a star isn't centered.

The big problem I've with objects that are not stars is when switching from eyepiece to CCD camera or maybe a DSLR chances are that object say, Orion isn't gonna be in the camera field of view.

Which is the problem I had and the reason I decided to get the starsense, they box says...

 

Multi-point star alignment provides extremely precise  GoTo pointing accuracy, centering the object in your eyepiece or camera every time. 

 

 

So the only thing it's centering for me is the stars.

If it's not a star it's not centered it's only in the eyepiece field of view.

Switch means if I was to switch to a imaging camera since the field of view is I guess smaller then a 40mm eyepiece chances are the object is gonna be either outside the field of view of the camera or possibly almost out of the field of view.

 

The only thing I can really do is possibly wait and try using the Starsense with my AVX mount possibly using a 5SE isn't the best way to use it, I'm gonna assume that the Starsense really only works with a 5SE or mounts like a 5SE for visual use maybe with a AVX mount after it's been polar aligned the performance will be like they advertise..

 

Something tells me that the problem is alt azimuth mounts.. I don't know why Celestron would not say that the starsense when used with a alt azimuth mount is only for visual usage I mean that technically would make sense alt azimuth mounts are not ideal for astroimaging so having a object like a Galaxy, Messier, Nebula not being centered in a alt azimuth mount is the reason.

 

Would be very interesting if that's the case to me that's what it sounds like, using a starsense with a alt azimuth will be good for visual use only and for a equatorial mount after being polar aligned will make it work as it's designed to do...

 

Also my Celestron SkySync GPS now no longer wants to work shows the wrong information once the GPS says linked, dates wrong, time is wrong, zone is wrong, latitude /  longitude  is wrong as well.

Tried factory resetting controller  didn't fix the problem tried a different  mount same problem.

 

Appears I'm not the only one who has had this problem with the SkySync GPS worked fine for me  for a while last two nights I seriously wondered why I had a bit of the problems I had after manually entering the information that problem was gone so didn't use the GPS decided to try again setup around 3 PM before dark GPS linked wrong information still.



#6 Noah4x4

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Posted 15 November 2017 - 03:39 AM

I understand the issue now;

 

When I first switched from an EP to CCD/DSLR camera it was a frustrating and frequent occurrence that my target (say, a planet) was typically outside the FOV as displayed on my laptop screen. Even if I hit it it first time it might drift out of computer screen FOV too quickly. The latter is a challenge of an Alt-Az scope unless polar aligned on wedge. Sadly, the SE4/5 wedge is too crude (n.b. I have a SE4 with crude built in wedge and Evolution on a proper wedge). 

 

This problem occured whether using HC or Starsense. Let me explain from the perspective of my 8" Evolution 'scope that was supplied with a 13mm & 40mm EP (but I have  many more EP'S today).

 

If you think about this, Saturn doesn't appear large even in a 13mm EP.  However, it will almost fill the screen in any of the laptop PC stacking APPS.   Your centre alignment, calibration and tracking hence needs to be ever more accurate the greater the magnification. The camera's magnification is huge compared to the EP's whilst its comparitive FOV is tiny. The only solution is to apply more user skill and get the cal-star absolutely centred whether using hand controller or Starsense aided. Then tracking has a chance of succeeding. This isn't easy with the human eye,  especially with old tired eyes like mine.

 

The technique that first worked for me was to defocus my cal-star into a big donut that is easier to centre. Then repeat MULTIPLE times in ever smaller EP's.  Even so, this was still a bit and miss. The secret is to invest in a combination of 9 x 50 illuminated RACI finderscope and more importantly, a 12.5 mm illuminated reticle cross hair EP.  You need to get your target cal star absolutely centre of the cross hairs. The finderscope is less critical, but it's accuracy  is a massive aide to help you get the cal-star into EP FOV without the donut/repeat multiple EP process.

 

But what is remarkable here is the apparent speed an object is moving due to the rotation of the Earth. I first respected this when attempting polar alignment on an wedge. If you don't twiddle it's knobs quickly your target will fast vanish and drift from the centre of the cross hairs (just as it does on your PC monitor!). Witnessing this will help you understand the challenge. A target is (in effect) moving 15° an hour. It will drift out of FOV of your camera in no time at all. But until properly aligned/calibrated, the necessary accurate tracking cannot commence.

 

The only solution is to apply exceptional user skill and diligence and a 12.5mm illuminated cross hair  reticle EP is what you ideally need for accurate centering, You might still struggle with an Alt-Az if not on a wedge as although tracking will be good it won't be as smooth as if polar aligned and RA only. A GEM mount is hence FAR easier. You need to be exactly in those cross hairs (like with rifle). Remember your planetary target is probably 8 astronomical units distant.

 

Starsense is a fantastic tool and once ACCURATELY calibrated and similarly adding additional alignment points it will reward the user with superb results. But there is no substitute for getting your cal-star dead centre smack in those cross hairs. A fraction out and you will fail to find/keep your target on your computer screen. Suggest you limit attempts at AP to your AVX mount. I get great results on my Evo + wedge, but it took me a year to fully master the required user skills. I would struggle to replicate on my SE4 and its crude wedge.


Edited by Noah4x4, 15 November 2017 - 04:01 AM.

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Posted 15 November 2017 - 11:23 AM

Thanks for the information Noah4x4, and everyone else who took the time to give feed back.

 

I kinda had a feeling that it possibly had something to do with a alt-azm mount, I've been planning to get one of them 12.5mm cross hair eyepieces, however my only problem with that is.. as you said trying to keep the star in between the cross hairs when doing a polar alignment, I guess the best thing to do is maybe time it just right by letting the star drift into the cross hair and then that might help.

 

The other problem is this is with my I think it's a 20-25mm  cross hair illuminated eyepiece hard to tell if the star is dead center of the cross hair or outside the cross hairs, few times it looked like it was possibly in the center but after checking the error it was still say 00 00 00 03  and 00 00 00 04 maybe to many 0's I added but rather then it being all 0's it had a 3 and a 4 at the end from both to top and bottom for example...

 

Then I tried another time where I was like OK! I'm gonna try one more time if I can't get this thing to be all 0's I'm just gonna have to deal with it cause I'm already into this by like 2-3 hours.

So the star happened to be slightly off to the left of the center of the cross hair said forget it that's  what i'll have to stick with for that night, check the errors it's all 0's ....



#8 Noah4x4

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Posted 15 November 2017 - 11:55 AM

Assuming you mean 00° 00' 00" in each axis for your polar alignment error I would say "unachievable" on a SE4 with crude built in wedge. I have got down to a PAE in arc-seconds on my Evolution with the more precise Evolution wedge, but rarely under double digit and never double digit in both axis. But surely you don't need such accuracy with a typical CCD/DSLR, and if you do, instead use your AVX GEM mount.

 

For example; with a Evolution wedge, each 1/5 of a wheel clockwise turn (e.g. one lobe) offers an adjustment of 5.4 arc minutes North if in Altitude and 9.3 arc minutes West in Azimuth. Hence to achieve a final adjustment in arc-seconds requires the finest shift of position.

 

The other issue is time. Take too long and the cal-star has moved. When I first started using a wedge without a 9 x 50 illuminated RACI finderscope it was taking me far too long to pull my cal-star back into the EP following an ASPA routine. As I said before, using Starsense on a wedge requires huge user skill (most people give up and get a GEM).

 

But there is hope. Celestron has fixed the 'bug' in the WiFi/APP controlled Starsense on wedge ASPA routine and the firmware is in beta-test. When released into the public domain it should make life easier for wedge users. But it has taken me a year of patience to master this challenge when limited to HC. Simulation Curriculum has also fixed the (different) bug in the WiFi/APP Starsense on wedge auto-align routine that tracks in Sidereal. There are other issues with the HC, such as odd things that happen with the display (see the link that follows). If you really want to master Alt-Az on wedge visit this thread, but it' a long learning  curve https://www.cloudyni...itive-guidance/


Edited by Noah4x4, 15 November 2017 - 12:05 PM.



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