How accurate

[brrttpaul]

should I be aiming for? I have just started guiding using PHD2 and I used the guiding assistant after 100 secs this was the read out,  RA 0.75 Dec 1.15 RMS 1.37 PA error 1.3 arc mins.  it seems all well and good but the graph seems to go a bit off after a while

[Marky1973]

Hi Paul

I usually aim to get the readings down below 1...think my last effort was around 0.5 and the graph was fairly flat. I think you have to be as accurate as you need to be for what you are imaging. My last outing was taking 3 minute subs of M13, so I reckon I could probably have gotten away with less accuracy than if I was planning 10 minute subs - I'm an amateur, so could be talking complete rot.

I don't drift align, just take time with PA and setting up the mount. Then 2 star alignment with the handset and onto PHD. Do you run a calibration in PHD before guiding> Once you select a guidestar, you can click SHIFT+GUIDE (IIRC) and that will force a calibration. Once complete, in the TOOLS menu you can see a readout of the calibration - a red and blue line will show the corrections made in the calibration. The closer these are to 90 degrees, and the underlying cross-hairs the better I believe

 

Mind you I think I need to check the mount configuration now I have looked at that again.... like I said, I'm figuring a lot of this out as I go along, so this could all be bunkum! :-)

 

[brrttpaul]

Hi Mark, didnt know I could do that if im honest I will have a look at it again and try and work it out, I can see as the night wears on it drifts out so been using that guiding assistant

[Marky1973]

I'm not sure I've ever used the guiding assistant, so I might have a look at that! :-)

[lrt75914]

Is there a difference between the guided/unguided error values? The lacerta autoguider will display values that are calculated to be the ra and dec error for an unguided mount. Should I still aim to keep them below 0.5?

Patrick

P.S.: Sorry to hijack the thread

[Marky1973]

Hi Patrick - I am afraid that is beyond my limited knowledge! Hopefully someone with more experience will be able to help you!

[brrttpaul]

im just looking at what you said now and (IIRC) I have no idea what that is, only thing i have come up with is (to reset calibration lol)

[alacant]

Hi

Warning: another PHD2 noob of 2 months writes

I think it depends on seeing. On a clear night I can get below RMS 1. Most nights -with haze from the sea, wind and drifting high cloud- 1.4. I think the main thing is to go ahead with imaging choose what and unless the images are suffering, forget it. Otherwise you end up staring at a graph on a computer screen all night!

Just my €0.02. HTH.