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Go Back   IceInSpace > Beginners Start Here > Beginners Equipment Discussions

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  #21  
Old 10-01-2018, 03:16 PM
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Merlin66 (Ken)
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You can leave the Dec live for calibration, then switch off for guiding.
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  #22  
Old 10-01-2018, 04:26 PM
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You must switch on DEC for calibration, don't forget. Otherwise it will calibrate only RA.

Also make sure you off-balance the mount right, as Ken already mentioned. This is almost a must for HEQ5/NEQ6 class mounts because of the backlash. Also you should guide only in one direction in DEC. Otherwise you may end up chasing the backlash.

And increase your exposure time to 2-3s. 1s may be too short and you may be chasing the seeing.

And run the guiding assistant to get recommended starting guiding parameters, which usually work OK. It will also measure the DEC backlash, post the image and numbers here.
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  #23  
Old 11-01-2018, 09:23 AM
Jasp05 (Aaron)
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The mount has the Belt kit mod on it. So I think this has removed most of the backlash? and I have been balancing slightly heavy on the side that sits against the drive motor. (Mount is turning RA clockwise so I balance to be slightly heavier on the east side).

So how do you know if your "chasing the seeing" as such. Because last night my polar alignment was slightly better again. (Used PHD2 tool initially and got to around 1' for both axis, then used a D.A.R.V drift align for 3 min on both axis to double check and it came out perfect).

However the DEC and RA would not behave for many hours. I think this may of been a result of that "chasing the seeing" as it was a very sawtooth like graph which corrections in both directions quite frequently.
Then all of a sudden RA was under 2 arc/sec peak to peak, but dec was still moving 5-8 arc/sec peak to peak.

It's just very puzzling that things can suddenly go from so bad to reasonably good in a matter of minutes. However I think it may of had something to do with the clouds last night. even though it seemed clear there may have been some very light cloud clover moving through.

Do you guys think it's worth the effort of tearing down the dec axis to see If I can make it smoother? Or is it just my setup and guiding settings? I'll post the log file from last night shortly.
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  #24  
Old 11-01-2018, 12:24 PM
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Lognic04 (Logan)
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If your total error while guiding on an eq6 or eq5 is around 1", then just leave it because that's perfect, unless you are using something high FL like an SCT. With a camera lens, you could be guiding at around 5" and still be perfectly fine.
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  #25  
Old 11-01-2018, 03:11 PM
Jasp05 (Aaron)
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So any tips on how to attain repeatable guiding results?. As they vary so much each time I setup.

As you say If I can guide within 2-4" peak to peak I'd be more than satisfied and happy with that. (correct me if I'm wrong but my camera and lens setup is around 3.75" per pixel. So if my guiding is under 4" I should be right? ).

But getting it to track like that seems to be taking me an exorbitant amount of time. (2hrs of setup and aligning and then messing with tracking to get it like that. Most of that time spent wondering why my guiding graph is sawtoothing around 5-8" peak to peak) .

Or is that a normal kind of time frame for a newbie like me?
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  #26  
Old 11-01-2018, 03:12 PM
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Beltmod does not necessarily mean that there won't be any backlash. There are several places that need proper tuning to minimise backlash. Even then lots (most?) of us guide in one direction in DEC only.

Also often a "perfect" polar alignment can be cause of problems as the mount may need to correct in both directions.


edit:
You should post logs and screenshots of when problems occur.
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  #27  
Old 11-01-2018, 11:53 PM
Jasp05 (Aaron)
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as an update. I tried guiding again tonight. most of the night my RA guiding was within 3" peak to peak and dec was around 4.5" peak to peak.

I believe the seeing conditions have been wreaking havoc on a beginner like me. The last few nights there must of been some high level cloud haze not visible by eye. As tonight tracking was pretty on point I thought.

all my subs came out really nice. So I can't complain. Guess its just a matter of learning the subtleties now and managing each nights seeing conditions.
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  #28  
Old 12-01-2018, 08:13 AM
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Quote:
Originally Posted by Jasp05 View Post
as an update. I tried guiding again tonight. most of the night my RA guiding was within 3" peak to peak and dec was around 4.5" peak to peak.

I believe the seeing conditions have been wreaking havoc on a beginner like me. The last few nights there must of been some high level cloud haze not visible by eye. As tonight tracking was pretty on point I thought.

all my subs came out really nice. So I can't complain. Guess its just a matter of learning the subtleties now and managing each nights seeing conditions.
Looking at the graph to get numbers isn't what you should be doing, look at the RA, DEC and TOT(al) error to the left of the graph. Also screenshots would help a lot.
But if you are getting round stars then i wouldn't worry about tweaking anything
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  #29  
Old 12-01-2018, 10:53 AM
Jasp05 (Aaron)
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This was my guiding results from last night.

Let me know if you see anything funny or things that I might be able to improve?

I know the Ra and dec agression is probably a bit high but it was working last night so I didn't tinker.
Attached Thumbnails
Click for full-size image (guiding graph2 11Jan18.jpg)
131.8 KB25 views
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  #30  
Old 12-01-2018, 11:28 AM
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Originally Posted by Jasp05 View Post
This was my guiding results from last night.

Let me know if you see anything funny or things that I might be able to improve?

I know the Ra and dec agression is probably a bit high but it was working last night so I didn't tinker.
Those results are great. Your exposure time could be raised to 2 or 3s to stop it being that aggressive and stop it chasing the seeing, but otherwise that is to be expected from a Chinese mount like the eq5.
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  #31  
Old 12-01-2018, 11:30 AM
Jasp05 (Aaron)
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Thanks Logan.

Now I know I'm on the right track I can keep plugging away and try to get things better over time.
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