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Atlas EQ-G Tracking Problems

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#1 tclehman1969

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Posted 21 April 2013 - 01:32 AM

Good evening,

Just spent tonight getting a chance to use my new Atlas mount at some length. But, I am a bit concerned about its tracking abilities. I did have a chance to get ot out and use it once before and tried a prime focus image of M42 which turned out quite well even though it was a very rough polar alignment, just stuck polaris at the center of the crosshairs in the polar scope.

Tonight, I spent more time aligning the scope and put polaris in the little circle where it was supposed to be. Did a 3 star alignment and then did a few pictures of the moon. It wasn't until after taking some video of Saturn (want to try my luck at stacking images for the first time) that when looking through the eyepiece I noticed how fast Saturn was moving through the field of view. Dreadfully bad. It was almost like using a scope without a drive on it. It was just trucking through the field.

Any thoughts on why this might be happening?

#2 Hilmi

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Posted 21 April 2013 - 01:50 AM

Depending how high magnification you have, it is most likely polar alignment.

#3 LazyLightning

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Posted 21 April 2013 - 02:10 AM

Also make sure your PA scope if aligned to your RA axis ( best done during the day ) and know how to look up Polaris' current position to correctly place it on the circular reticule.

Aligning the reticule tutorial can be found here:
It's done with a SkyView Pro, but the procedure is the same

http://www.andysshot...nmentScope.html

Then once aligned, use this program to calculate where the current position of Polaris is.

http://myastroimages..._by_Jason_Dale/

Doing the above will get you in good shape for both visual and Solar System imaging. If you plan to do long exposure AP ( especially without auto guiding ) you will need to drift align.

#4 gonzosc1

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Posted 21 April 2013 - 09:22 AM

Also make sure your PA scope if aligned to your RA axis ( best done during the day ) and know how to look up Polaris' current position to correctly place it on the circular reticule.

Aligning the reticule tutorial can be found here:
It's done with a SkyView Pro, but the procedure is the same

http://www.andysshot...nmentScope.html

Then once aligned, use this program to calculate where the current position of Polaris is.

http://myastroimages..._by_Jason_Dale/

Doing the above will get you in good shape for both visual and Solar System imaging. If you plan to do long exposure AP ( especially without auto guiding ) you will need to drift align.


+1, you must align the polar scope reticle before trying a polar alignment. when I got my eq6 the reticle was crazy off target!!

#5 tclehman1969

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Posted 21 April 2013 - 11:15 PM

Hey, thanks, all! After posting and seeing an initial quick response from Hilmi and Chris, my Type A personality took hold and I took the mount back out to my local "dark" site and tried again. This time, instead of trying to put Polaris in the little circle in the finder, I just put it in the crosshairs. Did my star alignment and low and behold, the mount held objects dead on. So, with that experience, I felt good about the mount again. I was worried something with the mount may be messed up.

So, looks like my next task is to verify the polar scope is indeed centered on the RA axis.

Also, quick question to make certain I am reading things right. When the hand controller shows Polaris to be at 02:38, I am assuming that means the RA axis is rotated such that the little circle in the polar scope is at the 02:38 location, so not quite 90 degrees from top dead center. Right? And then move the mount with the azimuth and latitude adjustments to get Polaris in the little circle, right?

Thanks for everything!

#6 John Carruthers

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Posted 22 April 2013 - 03:02 AM

check your manual, some give Hour Angle (24 hour clock, maybe counting backward from '12') other give 'clock angle' (usual 12 hour clock face).
If you use Polar Finder it gives a series of pictures where Polaris should be once you input your longitude and any daylight saving times.

Dion did an excellent polar scope alignment tut here;
http://www.astronomy...php?f=19&t=4006

fitting the thumb screws for adjustment is a great idea that save hours of frustration.

#7 ourobouros2k2

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Posted 22 April 2013 - 10:38 AM

Also, there are firmware updates for the atlas controller that has an alignment routine similar to Celestron's all star polar align. Does a good job and makes the user less dependent on the polar scope for good alignment.

#8 tclehman1969

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Posted 22 April 2013 - 02:00 PM

I've seen other mentions of this all star polar align, but I have to admit I don't know what it is. I did the firmware update to 3.34 but i didn't see anything different for polar alignment. Is it from somewhere other than the SkyWatcher site?

Right now, though, I want to get the alignment system figured out with what the Atlas came with. And I need to figure the difference between hour angle and clock.

Sadly, won't get a chance to get back outside until the weekend, but it will give me time to figure out how to align the mount! :)

#9 RMOrion10

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Posted 23 April 2013 - 02:17 AM

The Polar Realignment (like Celestron's All Star Alignment) protocol was included in SynScan Firmware Update 3.32. It was subsequently removed in Firmware Update 3.34 because it still required some "debugging".

There are Release Notes provided for each and every Firmware Update that detail all the changes made. The latest Firmware Update, 3.34, is so extensive that a new SynScan Hand Controller manual has been released to address the many changes to the menu items and features. If you've updated to 3.34 make sure to download and read it because some familiar features have changed drastically.

The SynScan should now display the Clock Position of Polaris in the Polar Scope, and Hour Angle, upon initialization. IF you have the GPS unit, it will do this right after getting the GPS fix.

The manual says this about using the clock position.

"6. Display Position of Polaris Relative to NCP
This step applies to an equatorial mount (or mode) only. It
specifies the orientation of the north star, Polaris, relative to
the north celestial pole (NCP) in the polar scope’s field of view.
• The LCD screen will display “Polaris Position in P.Scope =
HH:MM”. When using a polar-
scope to do the polar
alignment, user can imagine the large circle in the FOV of a
polar-scope as a clock’s face with 12:00 at the top, and put
the Polaris at the “HH:MM” position of the large circle.
• Press ENTER to confirm and proceed to the next step.
Press ESC to return to the previous
step."

For visual use, I have used the above protocol for years, even before Orion noted it in their manual since, with the installation of a GPS unit, the Atlas has always displayed the Clock position and hour angle of Polaris.

The next screen will display the hour angle though the manual has no instruction for using it. Rod Mollise (Uncle Rod) offers instructions here. http://uncle-rods.bl...-shoulders.html

In a nutshell, the procedure is, "After you enter time, date, and position, (or more accurately the GPS does the same), the HC will give the current hour angle of Polaris. Turn the mount in R.A. until the little circle on the borescope reticle where Polaris goes is straight down, and set the R.A. circle to read 0 hours.

Then, rotate the mount in R.A. until the “time” on the setting circle (inner scale in the Northern Hemisphere) is the hour angle given by the HC, adjust the altitude and azimuth of the mount to put Polaris in the reticle’s circle, and you have a very decent polar alignment."

Any of these methods is great for visual use. I don't care what alignment method you use, if you are going to do astrophotography, and expect decent results, you need to follow your basic polar alignment protocol with a drift alignment.

#10 John Carruthers

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Posted 23 April 2013 - 10:22 AM

up to v3.32 the PA routine didn't show up on the menu until a 3 star align was done, then the handset tells you each step to follow. Then you need another 3 star for accurate gotos.

So long as the polar finder is concentric with the RA axis and you use 'Polar Finder' you need not worry about hour angles.
Just set up for daylight saving, your position, and whether you want to see 'through telescope' view (yes) then match what you see in the polar scope to the picture.

Notice the Polaris position moves anti clockwise in the polar scope, 1 rev per sidereal day.

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#11 tclehman1969

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Posted 24 April 2013 - 12:11 AM

Wow, some great stuff here! Will definitely read the new manual for the controller since I have version 3.34. Kind of curious if after moving the mount on its RA and Dec axes for getting it polar aligned do you, once aligned, return the mount to the home position before doing a star alignment?

#12 John Carruthers

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Posted 24 April 2013 - 03:47 AM

You can restart from 'home'. Some people do a couple of iterations, PA/3 star/PA/3 star to get it spot on for photography.
You can always flash an earlier firmware if you want the PA routine.

In the field I use a little old Palm IIIx I bought from the bay for £3. It runs 'Planetarium' which I've oriented to match my polar scope view. I have it set for the NCP and it shows much the same as Jason Dale's Polar Finder ap.
Fine for setting up and visual, then I run the handset polar routine for imaging.






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