Guiding…..what is going on here please

[Andywilliams]

I am running a 150pds on a HEQ5 and guiding with an Orion ssg autoguider and PhD. I usually have no issues but in the last two sessions it has randomly done this.

can anyone advise please ? As you can imagine, the image associated with this is trailed !

many thanks in advance.

[Tomatobro]

A Gust of wind associated with the advancing cloud front ( star quality drop at the other end of the graph)?

Cable snags, voltage droop, intermittent connection somewhere, guide camera flexure, tripod leg sinking into the ground.

[Andywilliams]

34 minutes ago, Tomatobro said:

A Gust of wind associated with the advancing cloud front ( star quality drop at the other end of the graph)?

Cable snags, voltage droop, intermittent connection somewhere, guide camera flexure, tripod leg sinking into the ground.

That’s enough to be going on with eh 😆

thanks heaps ! I can definitely rule out wind and cable snags, so I will investigate the others.

thanks again,

cheers,

Andy 

[Tomatobro]

Just noticed you image from New Zealand so I would add Earth tremor........

I used to setup about 50 metres from a full width road speed hump and some high speed cars and vans would shake the ground enough that I could see it in PHD

[tomato]

The example you have posted is much bigger in RA, so potentially some random stiction of the RA drive (tight spot), or contamination on a gear tooth? No chance of anything nocturnal brushing against the mount or scope?

[michael8554]

No dip in the guidecam output.

PHD2 is reacting to an external input to Dec and  to RA.

I notice your Minimum Move settings are a tiny 0.05, was that recommended by the PHD2 Guide Assistant ?

And setting the Y-Axis to arcsecs give a more accurate account of the guiding than pixels.

You could post the PHD2 GuideLog for more information on your setup.

Michael

[Andywilliams]

6 hours ago, Tomatobro said:

Just noticed you image from New Zealand so I would add Earth tremor........

I used to setup about 50 metres from a full width road speed hump and some high speed cars and vans would shake the ground enough that I could see it in PHD

Thanks , it could indeed be….I can’t say I noticed anything at the time but with 30,000 earthquakes a year, most of which are unfelt, I couldn’t rule it out 👍

[Andywilliams]

4 hours ago, tomato said:

The example you have posted is much bigger in RA, so potentially some random stiction of the RA drive (tight spot), or contamination on a gear tooth? No chance of anything nocturnal brushing against the mount or scope?

I’m picking the former….. I was sat at my mount the whole time and there was no one else but me….not even my friendly hedgehog visitor 👍

[Andywilliams]

4 hours ago, michael8554 said:

No dip in the guidecam output.

PHD2 is reacting to an external input to Dec and  to RA.

I notice your Minimum Move settings are a tiny 0.05, was that recommended by the PHD2 Guide Assistant ?

And setting the Y-Axis to arcsecs give a more accurate account of the guiding than pixels.

You could post the PHD2 GuideLog for more information on your setup.

Michael

Thanks Michael,

this is where I have to put my hands up embarrassed and say that while I’m getting the hang of most aspects of astrophotography, PHD2 remains as gypsy magic to me 😬

Only recently did I discover that my eqmod settings were all wrong which explained why I couldn’t calibrate PHD2 successfully.

Can we assume that the rest of PHD2 settings are as they came out of the box. I did put the correct camera and focal length into the settings but in every other aspect, I have done very little with it.

I find the PHD2 instructions quite confusing 🤷‍♂️
 

I need to study more, or at least watch some good vids on YouTube !

Do you have any recommendations please ?

Cheers,

Andy 

[Tomatobro]

I find the guiding assistant really helpful for the initial setup. I know getting on with imaging is a priority but take the time to run the assistant and see what it tells you

[Andywilliams]

25 minutes ago, Tomatobro said:

I find the guiding assistant really helpful for the initial setup. I know getting on with imaging is a priority but take the time to run the assistant and see what it tells you

I will do so at the next session.

Thanks 😊