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How to improve tracking of Star Adventurer (with/without Guiding)

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#101 Alsterling

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Posted 19 September 2019 - 04:43 PM

Very frustrated with basic SA and phd2 setup... |Even on manual guiding, the mount goes into its blinking and the star visibly drifts in seconds. I leave it without guiding and with good polar align it stays nicely, BUT not good enough for a 200mm more than 40 sec.  Turn on align and within 5 seconds the star is moving off and the SA mount starts blinking. 

 

Wondering if the problem is with the mount itself?! I am using the Orion starshoot and as far as I can tell, all the settings recommended by people here, no dec, assume orthogonal, hysteresis 10, aggr 70 max ra dur 3000, min mov in pix 0.2. Good polar align. Have latest version of phd and started back to wizard and new equipment a couple of times. 

 

But click on guiding (and it does have green cross) and then the corrections keep increasing after only seconds! And can't even guide manually, which I really don't understand, so am thinking it is the communication with the mount. 2 nights of 2-3 hours was annoying!

 

Any thoughts would be appreciated.

Alister



#102 mxcoppell

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Posted 19 September 2019 - 06:22 PM

Is polar alignment good enough?


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#103 Alsterling

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Posted 20 September 2019 - 03:00 PM

Yes, Polar A is within 2-3 arcmin. I think my problem is that I have not let it calibrate! Will check again tonight.



#104 mxcoppell

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Posted 30 September 2019 - 09:34 AM

Yes, Polar A is within 2-3 arcmin. I think my problem is that I have not let it calibrate! Will check again tonight.

A better practice is to force re-calibrate after changing target. 



#105 RJF-Astro

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Posted 09 October 2019 - 04:09 AM

I guided my Star Adventurer for the first time yesterday. I had to get used to the bigger spikes and DEC drift in PHD compared to my HEQ5, but actually it went ok. My polar alignment was about 5-6 arcmin off. What made a big difference for me was changing the guiding interval from 2 seconds to 1 second, see the graphs below. At about 1/4th I changed the guiding interval.

 

guidinglog.PNG

 

It appears a tight leash is needed. Next step for me is polar aligning with sharpcap, see if it further reduces error. But the 30 second subs on 330mm look quite ok. 

 

 

 



#106 mxcoppell

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Posted 09 October 2019 - 09:22 AM

Yes, you got to use shorter guiding exposures for these small trackers. I do 1s on my previous Star Adventure and current AZ-GTi. The graph will be controlled much better.



#107 dbick

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Posted 19 October 2019 - 02:32 PM

I have about the same setup and saw a picture of what you described by putting the guide scope at the end of the weights bar.  I thought that would help with the balance so I called Sky watcher tech support to see if this would work.   They said NO, that I need to mount is on or with the camera.  They understood what I was doing but said that would not be accurate.  I didn't like it on the flash mount, so I devised a bottom bracket to mount it to the side for a lower center of gravity.Camera setup (Large).jpg



#108 mxcoppell

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Posted 19 October 2019 - 06:44 PM

From my previous experience, I don't think using the ball-head is a good idea. Most of the trouble I got was from the ball head. I would suggest you attach the lens directly to the DEC plate. 



#109 ariesram

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Posted 07 December 2019 - 10:57 PM

Is there anything to verify whether or not my copy of Star Adventurer is defective? 

 

I spent more than 10 or 20 hours doing polar alignment in about 10 trips in the field. 

2 out of 10 I got round stars with 1 minute exposure using 200mm lens. The rest are all trailing stars, a big waste of time and gas, and of course energy. 

 

I do not believe that I still do not have perfect polar alignment skills after 20 hours of trying. I use Polar Alignment Pro app, make sure everything is tightened, and I attached camera directly to the dovetail plate without ball head. Of course my camera and lens weigh less than 1/2 of 11 lbs limit. And I check polar alignment time and again, every time after adjusting camera. 

 

70mm lens, 30 second exposure is enough to show trailing. Not to mention 200mm.

 

Can we verify if the equipment is defective? Or is it only for wide angle lens? If yes then it's very limited usage. I can do 30 seconds using 20mm or shorter lens without tracking. Now I do not believe how those guys can claim they achieved round starts in 2 minutes exposure using 400mm lens. 



#110 tkottary

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Posted 08 December 2019 - 12:03 AM

Well it could be defective. Have you checked the following?

 

1. North / South hemisphere setting is correct as per your location ?

2. Tracking is set to Star?

3. How bad is your polar alignment. For 70mm as long as the  polaris is in the circle it should be fine, for 200mm you should be spot on.

4. There is a set screw on the flat surface of mount close to RA gear , if its too tight you will see weird results.



#111 ariesram

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Posted 09 December 2019 - 10:04 AM

Well it could be defective. Have you checked the following?

 

1. North / South hemisphere setting is correct as per your location ?

2. Tracking is set to Star?

3. How bad is your polar alignment. For 70mm as long as the  polaris is in the circle it should be fine, for 200mm you should be spot on.

4. There is a set screw on the flat surface of mount close to RA gear , if its too tight you will see weird results.

Can you point out which screw it is? Thank you. 

 

The rest of setting is correct. North Hemisphere, tracking set to star, Polaris exactly on the spot - verified using PS pro app, also using the date/time circle, timezone mark. 

 

I am also running an indoor 24 hour test. Will update if the laser mark returns the spot that it was 23 hours 56 minutes ago.

Attached Thumbnails

  • IMG_3590.jpg
  • IMG_3589.jpg

Edited by ariesram, 09 December 2019 - 10:05 AM.


#112 tkottary

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Posted 09 December 2019 - 02:32 PM

This one. Do you feel any stickiness with the clutch when it loose and you try to rotate. if the 24 hour test doest not work send it back for repair to Skywatcher.

set-screw.jpg



#113 ariesram

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Posted 10 December 2019 - 12:08 PM

Well, the 24 hour test turned out to be fine. I marked a laser point on the wall 21'5" from the SA. 23 hour 56 minutes later the laser point was only 1 3/8" away. this is about 0.3 degree. 0.0002 degree per minute. 

 

Also I calibrated polar scope as per the process on the manual. It is good, too. 

 

One more thing I did was tracking for 1 hour with my camera and lens on the SA, with and without counter weight. Turned out that both tracked at same speed, 7.5 marks on the date/time circle. Though odd, but proper counter weight may not be a key factor affecting tracking accuracy. 

 

Now that rotation rate is accurate, next step when it is clear night, I plan to shoot with 70mm focal length, with and without tracking, pointing to east and south to check DEC drift. If it is still trailing when tracking, then what is the cause, potentially? 



#114 Shopaholic

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Posted 11 December 2019 - 07:18 PM

Hi all, I have been reading all the threads in the post as I have the Star Adventurer  device and very much interested in accurate PA- but when I turn the date/month/time scales, there is no change in the orientation of the reticle? The reticle moves only when the dec bracket is rotated.  I really didn't see the point (read the manual) of the date correction without any mechanical connection.  Appreciate any clarification.

Polar Alignment

 

This is my soft spot. Because of the previous poor tracking records - I ALWAYS suspect if I did the PA correct. Really need a good test-run to confirm the method. Here is how I do the PA in the field. 

 

- Point the SA roughly to the Polaris direction. Normally I will try to play with the Horizontal Adjustment Knobs on the Equatorial Wedge to see if I have enough adjustment space on both side. So I don't have to move the whole setup for direction adjustment. 

 

- Before looking at the PA app on the phone, I need to make the '0'-'6' o'clock line vertical to the ground level with '0' at the top. To do this, I follow the instructions from the SA user manual as the following (page 23, item 2):

"2. Then rotate the Date Graduation Circle to align Oct 31 to the 0 of the Time Graduation Circle and turn Eyepiece/Mounting Platform to align the Time Meridian Indicator to the 0 of the Time Meridian Circle (Fig 27). This is the date and time when the orientation of Polaris is directly below the north pole (6 o'clock)."

 

Screen Shot 2018-01-06 at 10.47.35 AM.jpeg

 

By following the above steps, I could always make sure the mounting platform is at the right angle. 

 

- Set the Latitude on the SA Equatorial Wedge to the correct value (my case, is 32'58). Now look through the polar scope and use Latitude Knob and Horizontal Adjustment Knobs to find Polar and placed it at the right spot as the PA app indicated. 

 

IMG_3172.jpeg

 

Screen Shot 2018-01-06 at 10.49.46 AM.jpeg

 

- Start the 'STAR' tracking. That it for PA!



#115 DarkKnight

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Posted 02 January 2020 - 07:52 AM

Thanks for a great thread for a Star Adventurer newbie.

 

I've read it from Go to Whoa and seem to have missed the part where you find out how to point your camera at your target without a ballhead.

 

Thanks in advance for your help.


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#116 mxcoppell

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Posted 02 January 2020 - 10:22 AM

Thanks for a great thread for a Star Adventurer newbie.

 

I've read it from Go to Whoa and seem to have missed the part where you find out how to point your camera at your target without a ballhead.

 

Thanks in advance for your help.

That's the tricky part. Basically I would loose both RA and DEC clutches and move the camera pointing very carefully - avoid impacting the established polar alignment. There is no need to make RA clutch/knob extremely tight. So it will be much easier to loose and re-tighten it.


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#117 DarkKnight

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Posted 02 January 2020 - 10:15 PM

That's the tricky part. Basically I would loose both RA and DEC clutches and move the camera pointing very carefully - avoid impacting the established polar alignment. There is no need to make RA clutch/knob extremely tight. So it will be much easier to loose and re-tighten it.

Cheers Mate.

 

Just waiting on my D600 to come back from Life Pixel and I'll be ready for some serious confusion.  confused1.gif  




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