I'm a noob to all this sorry.. lol
I have a Skywatcher eq3 pro, and just started testing guiding with PHD2.
I'm using a ASI120MC-S with SVBONY mini guid scope 120mm
I had a small windows last night to test my rig after several setbacks, but now seems to be working fine.
I wanted to know if anyone knows if the guiding is ok given that I've taken the whole thing apart and changed the washers to pushbearings and regressed it with white lithium grease.
I don't know if the worm gears need to be adjusted further or settings in PHD2 that I need to adjust to get better guiding?
Your screen shot doesn’t really tell how well your mount is performing plus one nights guiding isn’t a good test either
To get a true indication you need to guide over many nights as atmospheric conditions vary so much plus imaging in different parts of the sky can affect performance ( eg lower altitudes )
But looking at your total error of around 1 arc sec , your on the right track
I’m not sure of the capabilities of this smaller EQ3 mount but time will tell with more testing
Hopefully folk can chime in who have a similar mount
Alternatively you can join the PHD2 forum and upload your log files so they can be assessed ( if you can be bothered )
The main thing with PHD2 apart from getting your mount balanced correctly in Dec and Ra is to get a good calibration at Dec=0 , near meridian
Also one thing I’ve noticed is that your using a colour camera as a guide camera , it does work but a mono ( ZWO120MM ) camera will detect better guide stars to lock onto plus has a lower noise threshold
Thanks Martin
I didn't know that's how it worked? I'll try it for a few more nights and see how it goes.
The camera was originally bought for planetary and im trialling it out for guiding.
Hopefully it will do the job well enough that i wont have to get a dedicated guide camera.
Try running the Guiding Assistant (under Tools menu). It will analyse the responses of your rig for a couple of minutes, report the accuracy of your polar alignment, and then make suggestions for fine tuning your parameters which you can adopt just by clicking on them. Once you've done that, turn to a field in the north, reasonably close to the celestial equator and force a calibration (shift click on the guiding button). Once it's all calibrated and running, look at the RMS figures reported in the bottom left hand corner of the window (not shown in your screen capture) - especially the total RMS error.
Once you've done that, turn to a field in the north, reasonably close to the celestial equator and force a calibration (shift click on the guiding button).
Didn't know that could be done. I've learned something today, thank you!
Try running the Guiding Assistant (under Tools menu). It will analyse the responses of your rig for a couple of minutes, report the accuracy of your polar alignment, and then make suggestions for fine tuning your parameters which you can adopt just by clicking on them. Once you've done that, turn to a field in the north, reasonably close to the celestial equator and force a calibration (shift click on the guiding button). Once it's all calibrated and running, look at the RMS figures reported in the bottom left hand corner of the window (not shown in your screen capture) - especially the total RMS error.
I've had PHD working for a while using the default settings and it's been working OK, but have always wondered if there was any way to fine tune it.
This is exactly what I've been looking for, next time I'm out I'll give this a try. Since I set up and tear down each night, should I run the Guiding Assistant for every session, or will once be enough?
The Guide Assistant in PHD2 is not a magical wand to improve your guiding error or stability
It monitors your mounts behaviour during an unguided period of 2 minutes or more under the current atmospheric conditions and then directs the mount back to the lock position whilst measuring backlash and polar alignment error.
It only makes recommendations to correct noted problems with your mounts ability to guide or lock on to that guide star.
I’ve found it very useful but not a magical wand.
I use different mounts ( EQ6-R and EQ8-R ) under completely different locations and conditions and have used the Guide Assistant with varied results particularly with Dec backlash values and Polar Alignment values on the same night. This proves that guiding is a moving target to some degree dependant on atmospheric conditions which can change during an evening together with the specific location in the sky ( lower altitudes
I prefer to use the PPEC algorithm in lieu of the default Hysterisis algorithm in PHD2 and have found it has smoothed out my guiding with a marginal improvement in error.
I haven’t used Hysterisis in nearly 4 years
Unless you have severe inherent mechanical problems within your mount, I’ve found the following items to be of more value than anything else in regards to PHD2 guiding -
Opt for Ascom pulse guiding recommended by PHD2 ( not ST4 ) ie Laptop cabled direct to guide camera
Good Dec and Ra balance ( Ra balance slightly “east heavy” )
Use the “Wizard” in PHD2 to set up your rig and guiding
Create a Dark Library and save it / use it ( Wizard will direct you )
Use the profile tool to achieve reasonable guide scope focus
Get a good Calibration at Dec = 0 near the Meridian and save it in Auto Save ( I’ve used the same calibration for over a year , no issues at all
Try the PPEC Algorithm
Don’t fiddle with the settings of parameters , defaults usually work ok
Just a note that if you adjust your polar alignment you get a warning that the calibration no longer matches, so if you set up each time and might have varying degrees of PA accuracy, it's worth redoing calibration each night. Only takes a few minutes.
A pleasure to help
We’re all still beginners no matter how many years under your belt , always learning in this hobby , it’s never ending ……..
Here’s a few of my PHD2 procedures and notes I put together over the last couple of years
Other folk may benefit as well ( if interested)
Cheers
Martin
I ran the PHD2 Guidingassistantbut no idea what any of it means.. The backlash test kept failingfor some reason as well.
Quote:
Originally Posted by Startrek
A pleasure to help
We’re all still beginners no matter how many years under your belt , always learning in this hobby , it’s never ending ……..
Here’s a few of my PHD2 procedures and notes I put together over the last couple of years
Other folk may benefit as well ( if interested)
Cheers
Martin
I ran the PHD2 Guidingassistantbut no idea what any of it means.. The backlash test kept failingfor some reason as well.
Ali,
Your issues may be 2 pronged ??
1/ Mechanical issues with the mount ( excessive Dec backlash ) What mount do you have ? Is it secondhand or new ?
2/ Failure of Calibration due to step sizes and the location in the sky where you performed your calibration. You must , I repeat you must Calibrate at Dec = 0 or close , on the east side of the north meridian near the Celestial Equator.
Here’s a link to PH2 trouble shooting which is well worth a read , particularly the part on Calibration
If you still can’t resolve your issues then it would be prudent to upload your log files ( before and post failure ) and post it on the Open PHD2 forum. Hopefully Bruce or Brian will see it and offer some practical advice , recommendations
I can’t really offer anymore help
Generally if you follow the procedures in my first reply post then most mounts will guide ok , however in saying that it only takes one piece of info not correctly entered or one task not adhered too and PHD2 will run into issues
With the backlash test failing it's sounding to me like a mechanical issue. You may need to adjust the worm drives a little to remove 'sticktion' (friction points) or excessive backlash that can't be recovered from.
From you very first image you're guiding didn't look too bad, but I would change from using "pixels" as units to arc-seconds - the pixels always look much better than the arc-seconds.
I adjusted the worm gears to the point whereby their was no movement or play without impacting and straining the worm gear rotation.
That said the Dec rotation on the mount is a little stiff when tightening the bolt that secures the dec to the mount, when slightly loosening the bolt its no longer secure.. need to work out how to secure it without impacting the rotation movement.
Last nights test was somewhat successful, i was able to get 3 x 200 sec subs until something went wrong with the Dec, the bolt self tightened
Ali,
Glad you are making progress with PHD2 guiding
Yes mechanical issues with mounts, particularly the smaller mounts like yours can be frustrating. Hopefully you resolve it soon
