PHD2 guiding

[Ortovosh (Hayden)]

Hi everyone... was having some issues guiding with PHD2... so on advice from an experienced astrophotographer, I mounted DSLR on my HEQ5 and tried to guide with that. Great success. See pics of RMS Error at 0.94, and a 30sec exposure with no star trails.

So... I thought I would mount my SkyRover115 Triplet and change nothing else. I mounted scope, balanced it... and went back to PHD2 and pressed auto star selection and pressed guide... and it was a disaster. Had the following message come up - PHD2 IS NOT ABLE TO MAKE SUFFICIENT CORRECTIONS IN RA. CHECK FOR CABLE SNAGS, TRY RE-DOING YOUR CALIBRATION, AND CONFIRM THE ST-4 CABLE IS WORKING PROPERLY. The RMS error just grew and grew....

So I re-did Polar aligning, reset calibration of mount in PHD2... then this message - ADVISORY-LITTLE OR NO EAST MOVEMENT WAS MEASURED, SO GUIDING WILL PROBABLY BE IMPAIRED. CHECK THE GUIDE CABLE AND SE THE MANUAL GUIDE TOOL TO CONFIRM BASIC OPERATION OF THE MOUNT. Again the RMS error was huge and got worse.

I have an EQMOD cable from hand controller port to Macbook, and Zwo 120mini Cam straight to Macbook. This was same cables for DSLR, except DSLR was plugged in rather than Zwo Mini guide cam.

Please help... I am very frustrated. If everything worked with DSLR mounted... seems weird that Scope would be different - as far as being able to guide.

Thanks

Pic 1. DSLR PHD2 screen
Pic 2. 30sec exposure using guiding with DSLR
Pic 3. Guiding with Zwo and Scope




sorry... having issues loading other pics... not important... you get the idea...

Pleeeeeeeeease help.

[Startrek (Martin)]

Just looking at your photo I noticed the following -
1/ Your not calibrated
2/ You haven’t created a dark library or bad pixel map
3/ Your trying to guide on a saturated star

All recipes for disaster

Here’s some tips and procedures to try and get you guiding

PHD2 Set Up and Guiding tips

1/ Try to Polar align to around 1arc 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/ Important- Build a Dark Frame library and a Bad pixel map to provide good calibration and stable guide star. PHD2 will only allow you to use one or the other

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 by PHD2 Developers) in lieu of ST4 connected guiding via camera to mount

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

13/ Try and avoid cabling 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
If the guide camera is USB3 it most probably will connect with a USB2 cable

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”

In addition there are some good YouTube clips to learn how to guide with PHD2

Also I strongly recommend to read the PHD2 manual page by page, it will solve a lot of problems step by step

Good Luck
Cheers
PS Hope others can chime in with some additional advice

Cheers

[Xeteth (David)]

Originally Posted by Ortovosh

I have an EQMOD cable from hand controller port to Macbook, and Zwo 120mini Cam straight to Macbook. This was same cables for DSLR, except DSLR was plugged in rather than Zwo Mini guide cam.

Sorry, I'm a bit confused here about what exactly your setup is.

Are you guiding with the use of the ZWO camera? If so, you'll need the ST4 cable to go from the ZWO cam into the autoguiding port on the HEQ5. When connecting to the camera and mount in PHD2 you need to select the ZWO camera then for the mount set it to "on camera".

You can guide without the ST4 cable, instead doing it through the EQMOD cable. You will need to set this up though, I'm not at my computer at the moment but if you let us know exactly what your setup is I can help out a bit later.

[Startrek (Martin)]

If your using EQMOD then Ascom pulse guiding is the PHD2 recommended way of guiding and not ST4 method ( refer my item 11 )
Ascom pulse guiding with eqmod requires -
EQ direct cable ( shoestring cable ) from laptop direct to mounts handcontroller port
USB2 or USB3 cable from guide camera direct to laptop
EQMOD settings for PHD2 attached

[Ortovosh (Hayden)]

Thanks guys... just came inside and read these tips. I will definitely make some changes next time I am out. Thanks so much ... this hobby is like trying to learn Chinese by reading VHS instructions in German.... LOL


and sorry... don't have ASCOM... I must have cables in wrong ports...

[Sunfish (Ray)]

Sounds confusing. If you are using an eqmod cable like me it goes from the hand control port to the computer. No hand controller required. Also , unless have ascom drivers from elsewhere you need to install ascom I think.

So maybe you were using an St4 cable for the guide camera . Hard to tell from your description. In any case if you change the setup and the pointing and alignment and zoom and focus are not the same, ie, not all pointing in the same axis as the mount, things may not work so well. Then will require careful alignment to each other and new calibration in PHD and taping down the focus.

[etill (Elliot)]

You appear to be using a mac from the first images you posted. I managed to get it sort of working with phd2 connected to the camera and the camera guiding via st4, it wasn't ideal though. It was a while back, it may be better now.

EQmod on a mac uses the indi drivers, I never did it, but it seemed to be documented as working in a number of posts around the place when I was looking into it.

I ended up using vmware fusion to run windows 10 on the mac and using that for guiding which worked fine, but i also had a spare windows laptop which i ended up using for astro stuff, don't need to leave my macbook outside that way.

You can probably get everything working natively on a Mac, but the path of least resistance is using windows..

[Startrek (Martin)]

Good observation Elliot, didn’t even notice that
Yes Windows best path to go with all Astro at least to get up and running without too much pain

[Ortovosh (Hayden)]

thanks everyone. Yes I am using a Macbook, but a techy mate is coming to sort out parallels for me so I can use Windows software. And yes I had cables in wrong slots. And yes I hadn't done any calibrations. Whilst its raining for next few days - I am watching a lot of PHD2 and SharpCap tutorials. Thanks so much to everyone who has guided me (no pun intended) in the right direction.