New to Astronomy, problems with alignment

[vertigo262]

also, this is what confused me the first time I calibrated was that, I align everything to home, or 0 marks, aligened it to polaris. The later told the computer to go to polaris. when the telescope slewed to polaris, it didn't point by going home, it pointed a different way, using RA. 

and I don't think it pointed exactly to polaris because my alignment was with home. so when I calibrate, do I do it with home position, or do I use the RA and the polarscope?

[IanL]

Just to clear one bit of misinformation up here, the brand of OTA is completely irrelevant;  the starsense is a separate lens/camera assembly so provided you are using a compatible Celestron mount (which you are) it will work.  Neither the starsense nor the mount know or care about which scope is attached to the mount - the only issue related to the scope is how well aligned to the mount it is.  Louise has already pointed out that there is a routine to calibrate the error in pointing between the starsense and the main OTA (google for "cone error" if you are interested, but basically it means that most scopes will be a degree or more off from where the mount is pointing and the correction routine will allow the starsense to compensate for that).

[Thalestris24]

Did just find these comments from a Baader planetarium PDF regarding the Celestron Starsense:

starsense“ contains a dedicated hand control unit (HC) and a CCD-camera module, both may be added to almost every Celestron GoTo tele- scope sold in the last 10 ye-

ars. (Note it does not mention any other manufacturer)

Also in respect of what the device does they put it: starsen- se is easily ancamera and a clever software wich is bringing professional „plate solving“ tech- nology into the hands of the astronomy ama- teur. 

​They also mention the EQ mount setup: star sense“ can also be attached onto equato- rial mounts. at first the user has to do a short polar alignment with the revolutionary Celest- ron „all star alignment“. It is only necessary to drive to one single star and center it with the alT and aZ axis. It does not matter wich star

it is, Polaris must not be visible. after performing this rudimentary „all star alignment“, the „starsen- se“ electronic takes over and takes 3 photos of the sky to find orientation. 

Bottom line I think that perhaps whomever sold the set-up should have pointed out it might not work without a celestron OTA...though seems short sighted of Celestron...though does enforce 'lock in' of consumers I guess.

Hopefully someone with a non celestron scope on a VX will be along shortly to put us all right ;-)

regards

Hi I think Celestron (either intentionally or unintentionally!) frequently refer to 'telescope' when they really mean mount. I don't think it should make any difference what ota one has providing it is on a compatible Celestron mount.

Disclaimer: the only Celestron hardware I own is a T-adapter

Louise

[Thalestris24]

also, this is what confused me the first time I calibrated was that, I align everything to home, or 0 marks, aligened it to polaris. The later told the computer to go to polaris. when the telescope slewed to polaris, it didn't point by going home, it pointed a different way, using RA. 

and I don't think it pointed exactly to polaris because my alignment was with home. so when I calibrate, do I do it with home position, or do I use the RA and the polarscope?

Hi

Polaris actually doesn't come into it, even when using the polar alignment routines (p15) which are separate from the star alignment (p11 et seq)

Louise

[wuthton]

Just to clear one bit of misinformation up here, the brand of OTA is completely irrelevant;  the starsense is a separate lens/camera assembly so provided you are using a compatible Celestron mount (which you are) it will work.  Neither the starsense nor the mount know or care about which scope is attached to the mount - the only issue related to the scope is how well aligned to the mount it is.  Louise has already pointed out that there is a routine to calibrate the error in pointing between the starsense and the main OTA (google for "cone error" if you are interested, but basically it means that most scopes will be a degree or more off from where the mount is pointing and the correction routine will allow the starsense to compensate for that).

Hi I think Celestron (either intentionally or unintentionally!) frequently refer to 'telescope' when they really mean mount. I don't think it should make any difference what ota one has providing it is on a compatible Celestron mount.

Disclaimer: the only Celestron hardware I own is a T-adapter

Louise

You both state in your sigs that you use Astrotortilla. 

Now.. It is a while since I set up Astrotortilla but I'm sure there was just a small part involving the field of view/image scale (please correct me if I'm wrong) and that said image scale will change dramatically with different OTAs. You can't just tell Astrotortilla that you use a EQ6 and away you go.

SGP requires the field of view to 3 decimal places to work well.

Why should this be any different for Starsense?

[Blazar]

Vertigo,

might be good to trawl through this thread: http://stargazerslounge.com/topic/193367-celestron-starsense-accessory/?hl=%20starsense

It goes from when the star sense came out. it appears it was good at finding and resolving stars, but solar system objects were not so great, and some put this down the time aspect. when people also got the skysync GPS, the solar system object gotos were spot on. Also there were firmware updates to be done to the hand controller....so something else to look at.

Good luck.

[Blazar]

Just to clear one bit of misinformation up here, the brand of OTA is completely irrelevant;  the starsense is a separate lens/camera assembly so provided you are using a compatible Celestron mount (which you are) it will work.  Neither the starsense nor the mount know or care about which scope is attached to the mount - the only issue related to the scope is how well aligned to the mount it is.  Louise has already pointed out that there is a routine to calibrate the error in pointing between the starsense and the main OTA (google for "cone error" if you are interested, but basically it means that most scopes will be a degree or more off from where the mount is pointing and the correction routine will allow the starsense to compensate for that).

Yep  I could see the argument as there is no 'intelligence' inside an OTA its the mount understanding where its pointing and the OTA is just along for the ride. I did point out the centring and offset routine to the OP in post 17 on the first page, and I think they were unsure if they had done this correctly. Lets hope it will be solved by redoing the initial calibration.

[vertigo262]

I updated the firmware so thats current. I will try to re calibrate it again. I'm assuming I can use polaris and everything at home position.  I can't remember my original calibration results because so much learning was going on at the time and I am new to this.

I might have had it aligned but watched it drift out of alignment which I then focused on polar alignment. Then the other night everything was way off. 

My first step is to get it to point right. then I will focus on polar alignment because I plan to do some photographu.

I appreciate the help from everyone. Although I might be back to this post and frustrated. lol

[Blazar]

Follow the manual to the letter....one step at a time. 

[IanL]

You both state in your sigs that you use Astrotortilla. 

Now.. It is a while since I set up Astrotortilla but I'm sure there was just a small part involving the field of view/image scale (please correct me if I'm wrong) and that said image scale will change dramatically with different OTAs. You can't just tell Astrotortilla that you use a EQ6 and away you go.

SGP requires the field of view to 3 decimal places to work well.

Why should this be any different for Starsense?

The difference is that the Starsense has a fixed lens and chip and the firmware knows what field of view it gives; it does not change if you change the main OTA.  With AT, you can use any ASCOM compatible camera and any OTA to take the images to be solved, so the field of view to solve will be different for each user's set-up.  (The benefit of AT is that, assuming you are using a laptop for imaging, you don't need any additional hardware - you just solve using your imaging camera and scope.  The benefit of Starsense is that it is self-contained and can be used for visual alignment/goto without a laptop).

[Thalestris24]

I updated the firmware so thats current. I will try to re calibrate it again. I'm assuming I can use polaris and everything at home position.  I can't remember my original calibration results because so much learning was going on at the time and I am new to this.

I might have had it aligned but watched it drift out of alignment which I then focused on polar alignment. Then the other night everything was way off. 

My first step is to get it to point right. then I will focus on polar alignment because I plan to do some photographu.

I appreciate the help from everyone. Although I might be back to this post and frustrated. lol

Hi

It's best to completely ignore Polaris and just simply start with your mount and scope pointing roughly north. Just follow the steps in the manual methodically!

Louise

[RichM63]

If it absolutely insists on being called a Celestron rather than a Meade, surely wouldn't 'telling it' that the OTA is any one of the C6 series of 150/1500 f10 range 6" OTAs work?

Agree about step by step.

[Thalestris24]

If it absolutely insists on being called a Celestron rather than a Meade, surely wouldn't 'telling it' that the OTA is any one of the C6 series of 150/1500 f10 range 6" OTAs work?

Agree about step by step.

The ota is irrelevant! It can be anything that sits comfortably on the Advanced VX mount. The StarSense works independently of the ota. 

(However, the OP is using a SCT which has a fairly large focal ratio. Once he has the rig alignment sorted, he'll need an oag when it comes to him attempting long exposure AP. F10 requires 4 x the exposure time compared to F5, i.e. a 5 min exposure at F5 needs 20min at F10 but he'll be able to improve on exposure times with the addition of a focal reducer.)

[SteveT]

Also, even with the latest firmware, the ASPA feature does not yet work properly, the engineers are still working on that so it will be off if you use that feature. (Source - Team Celestron forum - Derek firmware engineer). You may need to do a full reset on the SSA to get rid of old settings, especially alignment error data. If you go to the Team Celestron Forum, there are instructions there on how to do that (as well as a host of other tips and useful tips that help you find out what's going on).

[ollypenrice]

Does this mount have a polarscope? If it doesn't, sell it and buy one that does before all these bug riddled sofware gizmos drive you to distraction.

If it does, check that it is concentric with the mount's polar axis. Set the mount up in the daytime so you can observe a distant recognizable point (the top of a church spire etc) through the polarscope and rotate the mount in RA with the crosshair of the polarscope on that target. If the crosshair stays on the target you're good to go. If it describes a circle, adjust its three radial setting screws until it stays put as RA turns.

Use this calculator to find the Polaris position relative the the North Celestial Pole for the time and place of your setting up. http://www.trutek-uk.com/takahashi/polarisfinder1-2en.htm You can take a few paper versions for different times out into the field if necessary.

Use the polar scope to put Polaris in the right place and that, I promise you, is that so far as mount alignment goes.

The world has lost the plot in its mania for software solutions to every problem from alignment to brushing your teeth. You can take out a Takahashi mount, put it on the floor (no levelling possible or necessary) look through the finder scope and be aligned for long exposure astrophotography in two minutes.

If you find a bug on your polarscope, blow it off... 

Olly

[Thalestris24]

Yeah, I was going to suggest the op ditches the expensive but unnecessary Starsense gizmo and just gets back to basics! (But who am I to tell anyone what to do... )

Louise

[ronin]

I suggested the same in the person's other post.

I am guessing that at this time they are trying to work out 2 new things at once and some of the ideas may counter each other.

[vertigo262]

ok, so I went out tonight

and this is what happened. I successfully got my camera calibrated and everything aligned. Even semi Polar aligned.

My first problem was that I wasn't aligning to polaris. 

the second problem was that when I originally calibrated the starsense, I aligned it to what I thought was polaris, but in the home position, and did not point it with the hand controller first.

also, I noticed a huge fingerprint on the starsense lens which I cleaned off.

Finally, I successfully aligned polaris with the polar scope and put the moon almost filling the 24mm ep. it took about 12 minutes for it to drift to the edge.

so semi aligned for tracking. much better then before.

So this was a breakthrough for me because this is the first time out of 8 times out I got things aligned and was able to navigate. 

unfortunately, some sprinker water fried my skyfi, but hoping to go out tomorrow in a spot with less light pollution to try to see something worth while.

so thank you for all your advice on this matter. and maybe this will help some others with a starsense and advanced vx

still looking for advice on better tracking

[ronin]

For better tracking it is really a case of better polar alignment and setup detail, as in is the Latitude angle set as close as possible to your latitude, is the base of the mount as level as you can, is Polaris on the circle where it should be. I think the saying is: "The devil is in the detail."

What I do with my little goto's is take them outside when still light, and set up everyting as much as I can, much easier if it is not dark. Then I leave the scopes until I want to use them. Then it is a case of reapply power, double check everthing is as left and then I do the goto alignment. Nice, easy, relaxed.

For visual you could just about get by with closest mark to your latitude and polaris in the centre of the polar scope, but if you set up for AP which requires much better polar alignment you can spend 30+ minutes setting and getting everything as accurate as possible, then you do the goto alignment for that to determine whatever errors are still present and compensate for them.

I think it is a bit of a common idea that goto takes care of everything, it doesn't. It will sort of a hell of a lot of little errors but cannot do everything. I suppose the idea is read the name "goto" that is just one action, the track and follow is a bit of an "add on". To track accurately you put a guide scope and camera on.

[Blazar]

Have to agree with Ronin. 

Our advanced VX mounts are goto..so it will point at a set of co-ordinates based upon what you enter in the handset. If you enter the time / date wrong or have the latitude set incorrectly then the mount will 'goto and follow' the wrong 'patch of sky'. Thats all it can do (though precisely why you brought the star sense I guess to remove the calibration guesswork). 

So starsense will calibrate your goto function and map the sky for you (to use goto)....so it should do that, and then you can point to and follow a set of co-ordinates based upon how well star sense worked....it has not polar aligned your mount though. Thats a different function of the mount called All Star Polar Align (ASPA).

Using the ASPA function of the VX  and doing several of the routines can get you 30-60 seconds 'unguided' shots (and some have managed longer)....caveat here...not sure the ASPA function works with the star sense at the moment (something to check), I really think it might be good for you to have a go without the star sense, and learn to calibrate manually, and then doing the ASPA's for Polar alignment. It will help you get to know what your mount is capable of, and also help to get a handle on the stars and their names throughout the seasons (you will need your finder scope outback on though if you have taken it off to put the star sense on).

The subject of actually following a 'star' also known as 'guiding' and as Ronin states, is a whole different ball game which involves more equipment (a guide scope and camera and usually a laptop), though the VX will support guiding as it has a guide port. This involves the guide camera taking shots through a small guidescope, and then seeing if its target star has moved, and telling the mount to move to keep up. Using this method you could go for long exposure shots of many minutes to tens of minutes.

When I set up my VX I never align my scope directly on Polaris. I point the tripod North (follow the front two starts of Ursa Major to find Polaris), and then use the hole where the polar scope should go to sight polaris (putting it in the centre of my view (using the azimuth and latitude adjusters) knowing I will be doing the ASPA's to ensure the mount is polar aligned, and that I am roughly in the right place to begin with. I never sight polaris through my scope.

I also do a bit of work up front to work out what Star is best placed to use for the ASPA's routines using Stellarium.

If you can go out and get a bit further every night and see progress then everything is good. No need to rush the 'journey'...the stars are going nowhere. 8-) 

[PeterCPC]

Found this quote on a US supplier of Starsense "The Celestron StarSense works with most existing Celestron computerized telescopes and mounts. It will not work with other brands of scopes."

I also think that the word scope could refer to mounts but this is confusing because they clearly say scopes AND mounts. Some clarification from Celestron would be good.

Peter

[Blazar]

Might be good for you to have a look at Forest Tanaka's  4 part guide to astro photography.

Part 1 is here:

https://www.youtube.com/watch?v=9d0292TBMHo

Part 2 is about mounts and using them:

https://www.youtube.com/watch?v=zQB6UnrTEEM

[Thalestris24]

Found this quote on a US supplier of Starsense "The Celestron StarSense works with most existing Celestron computerized telescopes and mounts. It will not work with other brands of scopes."

I also think that the word scope could refer to mounts but this is confusing because they clearly say scopes AND mounts. Some clarification from Celestron would be good.

Peter

Hi

It's only the mount that needs to be compatible - I think they tend to call mounts 'telescopes' in the states! I posted this previously...

[PeterCPC]

Having read through all this, I hope that I have not misled anyone but I was only passing on what a supplier (who shall be nameless but not FLO) had told me. I think that it's the mount/scope confusion in the Celestron information that's at fault.

Peter