Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Tracking "Mode" vs Tracking "Rate"

  • Please log in to reply
14 replies to this topic

#1 dave23913

dave23913

    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 10 Jul 2016

Posted 21 November 2017 - 09:11 PM

So this will likely be a simple question to answer, but I'm looking to better understand the Tracking Mode selection on the NexStar HC for the AVX mount. Not being aware of this during my first imaging session recently, I setup everything as needed (level, polar align, star align, no guiding) and started a capture sequence on the North American nebula. The session worked as expected and I ended up with 20 good subs to work from. Then I happened to read about the Tracking Mode setting and saw (and confirmed) that it defaults to OFF when you startup the mount. The manual indicates that if this mode is set to OFF the mount will not move, so now I'm wondering what's going on. Hoping someone can explain more about this mode. Any help appreciated.



#2 xiando

xiando

    Aurora

  • *****
  • Posts: 4921
  • Joined: 27 May 2015
  • Loc: Cloudy NEOhio

Posted 21 November 2017 - 09:39 PM

I believe that once you have performed your star align (goto) with a Celestron rig that it will enter tracking mode automatically. So if that's right, then your were tracking but not guiding...The limits of the mount are what determines your tracking accuracy.

 

Tracking RATE refers to how often the mount is updating its position feedback and sending out corrections, afaik.

 

Tracking MODE refers to  whether you are tracking stars and DOS (sidereal), planets, the moon or the sun, each of which has an optimal (most precise) tracking MODE different from the others.

 

I had them wrong according to the nexstar manual (was thinking guide rate, which is different)

 

Tracking rate - Sidereal, Lunar, and Solar.  - each of which has an optimal (most precise) tracking MODE different from the others.

 

Tracking mode - Alt az, EQ-North, EQ-South, off. Alt-az mode, EQ (N/S) (with Alt-az mount and wedge for instance), and disable tracking (off)


Edited by xiando, 21 November 2017 - 09:51 PM.


#3 ram812

ram812

    Viking 1

  • -----
  • Posts: 627
  • Joined: 10 Dec 2014
  • Loc: Grants Pass, Oregon

Posted 21 November 2017 - 09:43 PM

"Mode" goes to lunar (Moon "Moves" at a quicker rate), Solar (Still different than lunar), and "Sidereal", which is pretty much every thing else in the cosmos' related to( Earth's spin rate). This is setup either prior to are after start-up, depending on what you are taking a picture of. The "Rate" setting can get you to your target quicker (By setting it at 9) also called "Slew Rate". This is explained in the manual quite well and how to use them, like "Guide Rate" and such. Ralph



#4 james7ca

james7ca

    Aurora

  • *****
  • Posts: 4745
  • Joined: 21 May 2011
  • Loc: San Diego, CA

Posted 21 November 2017 - 10:15 PM

xiando (eventually) explained it correctly. However, once set and if you don't do a explicit factory reset then the tracking rate and mode are remembered between sessions (even if you power off the mount).

 

Generally, you will never turn the tracking mode off, but you may change the tracking rate (just remember to set the latter back to sidereal before you try to do any DSO photography). If you want to pause the tracking you can use the Hibernate feature and the latter even allows you to turn the power off to the mount (but still retain your previous alignment).


Edited by james7ca, 21 November 2017 - 11:22 PM.


#5 dave23913

dave23913

    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 10 Jul 2016

Posted 21 November 2017 - 11:03 PM

Thanks for the information provided so far. Just to clarify, on the AVX mount (maybe others as well) when I power on the mount, Tracking Mode defaults to "Off". It does not remember this setting if it is changed. The default Tracking Rate is "Sidereal", so unless I plan to view/image solar system objects this never has to be changed. For this hand controller the slew rate is actually referenced as "Motor Speed" (unrelated to Tracking Rate). So the statement from xiando appears to be what is happening (i.e. "...once you have performed your star align (goto) with a Celestron rig that it will enter tracking mode automatically). Because the mount appears to track normal regardless of the Tracking Mode setting, it would be nice to confirm when this mode would be useful. May have to ping Celestron on this subject, but welcome any other feedback. Great group of people on this forum. Appreciate the help smile.gif.



#6 james7ca

james7ca

    Aurora

  • *****
  • Posts: 4745
  • Joined: 21 May 2011
  • Loc: San Diego, CA

Posted 21 November 2017 - 11:21 PM

No, on my Celestron AVX the tracking mode and rate are remembered. I haven't changed the tracking mode since I first started to use my AVX several years ago.

 

You want to use the sidereal rate for all planets and deep space objects, use the lunar rate for the moon and solar rate for the sun. But note, the lunar and solar rates are only approximate, since these rates change day-by-day and week-by-week and the AVX just uses an average rate for both of these objects (and the mount doesn't automatically track in declination and both the moon and sun also move in that axis).


Edited by james7ca, 21 November 2017 - 11:48 PM.

  • MCovington likes this

#7 MCovington

MCovington

    Soyuz

  • *****
  • Posts: 3504
  • Joined: 13 May 2014
  • Loc: Michael Covington - Athens, Georgia

Posted 21 November 2017 - 11:52 PM

Mode is how the mount is set up relative to the pole.  Fork mounts can be either alt-azimuth or equatorial (in the northern or southern hemisphere).  GEMs are always equatorial but still need to be told which hemisphere they're in, or rather which pole they're pointed at (if you're exactly on the equator you could do it either way).

Rate is how fast the mount moves in right ascension: sidereal (to track the deep sky), solar (to track the sun; also close to right for most of the planets much of the time); lunar (the moon, orbiting around the earth).



#8 dave23913

dave23913

    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 10 Jul 2016

Posted 22 November 2017 - 01:43 PM

Thanks jamees7ca and MCovington for the additional comments. I may need to take a look at my HC firmware, because my tracking mode always reverts to "Off" after power cycle. I'll post results once done. Thanks again for the help.



#9 james7ca

james7ca

    Aurora

  • *****
  • Posts: 4745
  • Joined: 21 May 2011
  • Loc: San Diego, CA

Posted 22 November 2017 - 06:39 PM

Thanks jamees7ca and MCovington for the additional comments. I may need to take a look at my HC firmware, because my tracking mode always reverts to "Off" after power cycle. I'll post results once done. Thanks again for the help.

That's odd, like I said I've only ever had to set the AVX's tracking mode once (when I first got it).

 

Does your realtime clock work (it should keep time while in use)? If that isn't working also then maybe you have a problem with the battery that is in mount's controller (inside the mount, NOT in the hand controller).

 

Check out these posts:

 

  https://www.cloudyni...o/#entry6807108

 

  https://www.cloudyni...f/#entry5556326

 

According to one thread this is a CR2025 (coin size) battery. Oh, and you need to turn the RTC on for it to run, it's apparently an option somewhere in the menu system.

 

In any case, I don't know whether the battery affects other settings, it may not.

 

You may also want to check whether you are running the latest version of the firmware. In fact, if none of the above seems amiss then you may want to try a factory reset on the mount itself (but after doing that I think you'll have to go through the initial setup again). Actually,  I can't remember whether I've ever done a factory reset on my AVX, however, I have had to do that on my CGEM now and then.

 

In any case, you should check everything else out before you try to change the battery, since access to the battery requires you to remove the mount's controller board.


Edited by james7ca, 22 November 2017 - 06:52 PM.


#10 dave23913

dave23913

    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 10 Jul 2016

Posted 22 November 2017 - 07:00 PM

I heard back from Celestron today. According to them, once the AVX tracking mode is selected it is remembered between power cycles, but the menu “selection” always defaults to Off. This only means that it is the default selection and does not reflect the current tracking mode. Good to know, but interesting that this is different from other menu items. As an example, when I use the menu to turn the GPS on and go back to this after a power cycle, the menu item reads “Turn GPS Off”. So it seems to reflect the current state of the GPS. They also said that after an alignment, the mount will start tracking automatically. So this supports what xiando wrote in the first reply. Aside from this oddity, the mount is working beautifully. Thanks again for everyone’s help. 


  • xiando likes this

#11 MCovington

MCovington

    Soyuz

  • *****
  • Posts: 3504
  • Joined: 13 May 2014
  • Loc: Michael Covington - Athens, Georgia

Posted 22 November 2017 - 08:06 PM

Tracking is off until you align; then it turns on.



#12 james7ca

james7ca

    Aurora

  • *****
  • Posts: 4745
  • Joined: 21 May 2011
  • Loc: San Diego, CA

Posted 23 November 2017 - 02:01 AM

Tracking is off until you align; then it turns on.

Well, what do you mean by "until you align?" I almost NEVER use Celestron's All Star Polar Alignment and seldom do I use calibration. Sometimes I use a PoleMaster, but normally I just set the tripod down on some marks on the concrete and then set the mount position to the home marks and then turn the mount on and check the time and date and then tell it to use the last alignment (which I guess is a form of alignment, but certainly not something that you really have to do as in "until you align"). But the previous is all part of the normal initialization for the mount, I really don't do any true alignment (unless I use the PoleMaster). After the startup I then slew to the first target (normally the moon or a planet with my C6) and sync. 

 

So yes, you have to go through the startup process but you don't absolutely need to do any alignment procedure when you start the mount. So, is it the "alignment" or the fact that you turn the mount on and complete the initialization sequence that starts the tracking? Note, it also must be tracking when you are actually doing the alignment, otherwise the alignment and calibration stars would drift from your field of view.

 

I don't know, if you've turned the tracking off then maybe it skips some of these steps, but normally you can't even get to any of the handcontroller functions until you've done the initialization and by that time the mount should be tracking.


Edited by james7ca, 23 November 2017 - 02:50 AM.


#13 MCovington

MCovington

    Soyuz

  • *****
  • Posts: 3504
  • Joined: 13 May 2014
  • Loc: Michael Covington - Athens, Georgia

Posted 23 November 2017 - 09:33 AM

My understanding is that tracking turns on when you have made an alignment choice, which might be "Quick align" or "Use last alignment" although in my case it is "Two star align."

 

You're quite right that there is no obvious way to bypass this step.  That's why I'm a little puzzled that others are reporting finding tracking turned off.


  • xiando likes this

#14 xiando

xiando

    Aurora

  • *****
  • Posts: 4921
  • Joined: 27 May 2015
  • Loc: Cloudy NEOhio

Posted 23 November 2017 - 09:52 AM

When my Celestron mount powers on, it is not tracking. It will remain in that state until I perform a star (Goto) alignment. It does not just suddenly start tracking after some time passes, like a computer booting up goes to windows or whatever OS screen. It idles in "not tracking" mode until that step has been completed, be that by whichever star alignment one chooses (and maybe even by forcing it with a config change, although I've never tried that as it seems illogical.)

 

I'm not sure how it works with the iOptron mount I use mostly now, but it doesn't matter. I religiously perform my polar alignment, then my star alignment, then I calibrate and start guiding on the alignment star (I use one star) until I'm ready to move to target.


Edited by xiando, 23 November 2017 - 09:53 AM.


#15 james7ca

james7ca

    Aurora

  • *****
  • Posts: 4745
  • Joined: 21 May 2011
  • Loc: San Diego, CA

Posted 23 November 2017 - 04:30 PM

Can't we just say that the mount doesn't start tracking until you've completed the mount initialization via the hand controller? This requires that you to answer several questions and perform several checks or procedures (potentially),  one of which is the action to select an alignment method (which just happens to be the last item in the list during the initialization procedure). At best, you might say that you need to select the alignment method before the mount will start tracking. But, that is different than saying that you need to "align the mount" or that you need to "perform a star (Goto) alignment" before tracking is enabled.

 

However, there is no standard way (that I know of) to bypass any of these steps, so it's not like you can start your mount without tracking being enabled (unless, I suppose, that it is turned off in the options, that being the tracking mode).




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics