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Old 18-08-2019, 02:39 PM
Startrek (Martin)
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Startrek is offline
 
Join Date: Dec 2017
Location: Sydney and South Coast NSW
Posts: 5,990
Todd
Below are some guiding tips I set up for myself 2 years ago when I first started using PHD2
They may be of some help to you ?

PHD2 Set Up and Guiding tips

1/ Try to Polar align to within 2 arc minute error on Alt and Az

2/ Auto select guide star (recommended by PHD2) or manually select star that’s not too bright or saturated to avoid lost stars

3/ If guiding is poor ( above 2 arc seconds ) utilise the Guiding Assistant

4/ Check and adjust focus of your guide scope and camera to minimise lost stars

5/ Set your guide camera exposure time between 2 and 4 seconds ( Looping ) 2 seconds is a good starting point

6/ The SNR value of the guide star should be between 15.0 and 40.0 to avoid losing the guide star

7/ Don’t over correct settings , under correcting will let you manage your guiding performance better

8/ If Guiding is poor try and keep your min mo above 0.25 in RA and DEC . Don’t go above 0.6. A good starting point for min mo is 0.20 or 0.25

9/ Build a Dark Frame library and a Bad pixel map to provide good calibration and stable guide star

10/ The RA Osc value should be between 0.3 to 0.5
If it drops to 0.1 or lower then increase the RA aggressiveness or decrease the hysteresis
If it gets quite high say 0.8 then reduce the RA aggressiveness or increase the hysteresis

11/ Use Ascom Guiding - Laptop direct connect to mount ( preferred) in lieu of ST4 connected guiding via camera to mount

12/ USB 2 cable to camera is not to exceed 5 metres

13/ Do not cable through a hub even a Powered hub, direct connect to the computer , you will have less issues

14/ Ensure you have the latest driver installed for your guide camera

15/ If guide camera is USB2 make sure you connect into a USB2 port with USB2 cable
And likewise with USB3

16/ Ensure you enter all the correct data for your guide camera into PHD2 brain tabs

17/ Make sure you get good Calibration. Calibrate within 10deg of celestial equator and within an hour of meridian
Once Calibrated save it and reuse it ( go to Brain in guiding tab and tick box “Auto restore Calibration”)

18/ if you lose guide star often , go to Brain in guiding tab and increase “Search region” and increase “ Star mass detection”

PHD2 Extra Guiding Tips

1/Try and keep your min mo in RA and Dec just above your arc sec error in both axis or leave as default (0.20) and see how the guiding performs over a few minutes
2/ Only make small adjustments in RA and Dec Aggressiveness. Wait for guiding to run for a few minutes to see any change or improvements
3/ If guiding is saw toothing in RA ( blue ) badly you are over correcting , reduce RA Aggressiveness and increase Min mo in RA only
4/ If DEC ( red ) is staying for the most part above the centre line you are under correcting , so increase DEC Aggressiveness a bit and reduce Min mo
5/ If guiding is still bad , run the Guiding Assistant to see what can be done
6/ Only use the Backlash Compensation setting If Guiding Assistant advises to do so.
Go to Brain then Algorithms
Use only if your backlash value from the Guiding Assistant is 3 seconds or less or if the Guiding Assistance says to use this function

Cheers
Martin
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