Out of the box PHD not guiding

[Ivor]

I've been having a bad run with my hardware recently not only with the camera but also the PC which has required me to completely re-install windows. Last night was the first the night I'd had the opportunity to test the PC outside with real targets.

I use ASCOM, EDMOD & CdC to drive the mount, AstroArt imaging and PHD for guiding, other than adding location and filters into the software everything is factory settings.

With the mount polar aligned I slewed and sync'ed to Epsilon Cassiopeiae using CdC, I then moved the scope to IC1805 realigned and focused. Whilst the camera was cooling I powered up PHD set it to the ASCOM driver mount control, picked my star and pressed the calibration button. Once the alignment had completed it informed me that there was insufficent movement in DEC so it was cancelled guiding in that direction which I understand means my Polar alignment is good.

I've got my green box, cross-hairs and the camera is cooled so I do my test shot and this is where it starts going wrong as the green box slowly slips away from the cross hairs enough to impact the image. To work out what is wrong and increase the error I realign to M45 and produce a log file the error reproduces itself with a greater magnitude as expected but I'm none the wiser to why.

Image



PECREP



I also tried guiding in AstroArt and it produced a similar response so I'm wondering if I need to adjust something in EQMOD, any suggestions?

[MarkS]

Insufficient movement in any direction (RA or Dec) is a bad thing.  But it usually happens in RA, not Dec.

Check the Dec pulse guide rate that has been set (or defaulted) in EQMOD.  You must click on the spanner icon to bring up a huge window full of various settings.  If it is zero or if the Dec checkbox is not ticked then that would definitely cause your problem.  

Mark

[Ivor]

The current setting are the default ones, it's a EQ6Pro what do you have yours set to?




I'm starting to come back to me now, I think I remember Duncan mentioning upping these before.

[mickw]

The current setting are the default ones, it's a EQ6Pro what do you have yours set to?

If I remember correctly setting Dec Rate to .5 solves a few issues, I think the same applies to RA Rate as well

[JohnP]

Dunc's the pro at this but I believe there is a setting in PHD where you can increase the time allowed for calibration to make sure there is sufficient time to move.. John

[Mike]

Increase the rate setting to .4 or .5 and run the calibration setting inside the PHD settings, where you have to put the focal length of the scope etc. in - It will then calculate the optimal amount of time for calibration. It's usually over 1000ms.

[Ivor]

Thanks, I'll have a play tonight if the clouds hold off long enough.  I will have to document all of the setup procedures, I also got caught out on my filter wheel I couldn't remember which order I had the filters, luckly I still had the old HD, so I had to take the laptop apart reinstall the old HD and run AA5 and write them down.

[Mike]

Thanks, I'll have a play tonight if the clouds hold off long enough.  

Surely you'll be at tonight's meeting not in your garden?  

Oh, and also make sure you're using PHD2 and not PHD.

[Ivor]

I wanted to come tonight so I could pick up a couple of calendars but alas I can't come as my 15 year old daughter is at a concert until 22:30 and it's netball night for my wife so no baby sitter

I had a look for PHD2 the other day but I couldn't find the right download https://code.google.com/p/open-phd-guiding/ am I looking in the right spot?

I was keen to get a copy so I could do a guiding comparision between PHD, PHD2 and AA5.

[MarkS]

PHD2 is at http://www.daddog.com/phd2
I played with PHD2 for the very first time last night.  Quite liked it except for a couple of bugs.  The integrated  drift alignment is a cool feature - it's the first time I've ever done drift alignment and it was a breeze!

Don't open the AOG window my mistake - it crashed my PHD2.
It also didn't always start guiding - it often came up with the message "guiding has stopped" even though I had just hit the PHD button.  It often took a few attempts before it would actually start.  Odd.

[The Thing]

I have been using PHD2 for quite a while now. It can calculate the duration to achieve the desired number of calibration steps (Brain/Scope[Calculate]). Works a treat. Usually 12 steps are used, more is a waste of time and fewer steps not statistically enough to smooth out movement issues. I haven't tried using the Graph and the Trendline function to do PA with drift alignment, must have a go, I have been using Astrotortilla and PoleFocus and just use the graph top confirm the adjustments I have made.

In EQMOD you should start with the guide rate at 0.5. Ivor, you have it at 0.1 which means only a tenth of PHD's command for duration is passed to the mount, so you get very little movement. PHD wants to move your mount 5% of the pixels in each direction to do the calibration. Theoretically you should be able to use a guide rate of 1 as PHD should just generate shorter commands, but no one seems to use this in practice. I suspect it's something to do with response time of the mount, you need a longer pulse to get some action.

PHD2 is still Beta software hence the bugs. A full release will happen 'real soon now' as they say! Leave feedback on the Google forum (you found that Ivor) so the bugs will get ironed out.