Username:

Password:

Altair AstroDIO DehumidifiersAtik CamerasModern AstronomyDavid HindsNe3 Filters

Author Topic: More SGP questions  (Read 830 times)

0 Members and 1 Guest are viewing this topic.

Offline Phillyo

  • Poster God
  • *****
  • Posts: 1492
More SGP questions
« on: 16:28:28, 02 November, 2015 »
So I've been using SGPro for a while and it's good, I like it. However I do have a few gremlins lurking in the system that i've just put up with until now. I'd really like to get them ironed out.

1. I cannot get an accurate V curve going. Sometimes it's a W looking thing, sometimes it flat lines. When I try to see what stars it's using it's picking up hot pixels when it's too out of focus and incorrectly saying a very low HFR rating. I've tried adjusting the sliders but I don't know how far to go? Also tried adjusting the 'crop' from 5% up to 30% but haven't used it yet as fog rolled in. Any suggestions? Also, it takes an age to do a focus routine. Like 10min or more. I'm thinking that's more due to the very slow transfer rates from the QSI583 than anything else!

2. This is the biggie. Once I've selected my target and framed it using the framing wizard. I assign a folder to save it in, select what filter, how many lights, exposure length etc etc. I open up PHD2 and connect everything. From my understand I should then be able to just press "Begin sequence" (or whatever it's called) and it should just run. The issue I'm having is that it'll correctly and accurately slew and centre the target using Pinpoint plate solving, run the (slow) auto focus routine but then it will just stop and initiate the end of sequence procedure and the fault "Guider failed to settle" will be displayed in the fault log. However it hasn't even tried to start the calibration for the guider? Or, when it does do the calibration it still says it's failed to settle and it'll stop. It's frustrating the hell out of me!

At the moment I have to manually centre it, do the auto focus, then manually calibrate PHD2 and begin guiding. Give it a few seconds to start guiding then proceed to begin the imaging routine. It works, but not how I want it to.

Any suggestions from other SGPro users would be helpful. Failing that I'll pop onto the SGPro forum and ask over there...but it's a big scary place and I don't know anyone! :(

Thank you in advance.
Phil

PS. If you need any kit info/image scale etc just let me know and i'll post it all up (image scale is 3.18!)
Astrotrac | Avalon Linear Fast Reverse with EQmod | WO Star 71 | Astrodon 3nm Ha, 5nm SII and 5nm OIII | Astro-modded Canon 450D | QSI 583wsg | Lodestar X2 Guidecam | Sequence Generator Pro | Pixinsight

Online chris.bailey

  • Administrator
  • Galactic Poster
  • *****
  • Posts: 9519
  • If at last you do succeed, don't try again
    • Rosemount Observatory
Re: More SGP questions
« Reply #1 on: 17:21:28, 02 November, 2015 »
Phil

I don't know too much about SGPro but I do know that a FocusMax Autofocus run completes in under two minutes and thats with some pretty hefty convergence steps turned on. I don't particularly like Autofocus routines that reverse focus direction to complete, @focus does the same, for a couple of reasons -

1) Focuser backlash is very hard to measure and tune out completely.
2) With stepper motors a loading step can be smaller than an unloading step.
3) If the stepper is attached to the fine focus knob, there can be significant slippage especially when turning against the load.

FocusMax approaches focusing very differently. The characteristics of the focuser are measured by a series of VCurve runs to determine the slopes either side of focus. These reman valid as long as nothing changes in the imaging train so can last for months. These are then used in a focus run to determine a point on one of those slopes and the final focus move is made in one direction from that point. It does rely on moving off target to a focus star but with plate solving, returning to target is a non issue and it also allows focusing to be set to take place on a star at a decent altitude rather than down in the murk.

From the description of your focus runs I suspect you have a bit of slippage, a good way to test this is if the step at which best focus is determined changes if multiple concurrent focus runs are completed.

I have moved the stepper motor over onto the coarse focuser and geared it 8:1 with timing pulleys and a belt so as to get a decent number of steps in the critical focus zone. I also put a dial gauge on the focuser to set the backlash value such that 10,20,50 and 100 steps in and then out brought the focuser back to the same point. It does still vary a little with the number of steps used but is pretty close.

Chris
LX200|ZS70|FSQ85|FLT110|Altair DF250RC|EQ6 Pro(Rowan Belt Mod)|ParamountMX
ATIK383L+/EFW2/OAG|Lodestar|Baader 36mm LRGBHaSIIOIII
Starlight Express SXVRH16/ONAG/FW|Lodestar X2|Baader 2" Filters
Starlight Express SXVRH814/ONAG/FW|LodestarX2|Baader 2" Filters
Lunt LS60PTBF1200|DMK41|Quark Chromo
Samyang 135mm f1.8

Offline ChrisLX200

  • Poster God
  • *****
  • Posts: 2281
  • Macclesfield UK
Re: More SGP questions
« Reply #2 on: 17:40:56, 02 November, 2015 »
So I've been using SGPro for a while and it's good, I like it. However I do have a few gremlins lurking in the system that i've just put up with until now. I'd really like to get them ironed out.

1. I cannot get an accurate V curve going. Sometimes it's a W looking thing, sometimes it flat lines. When I try to see what stars it's using it's picking up hot pixels when it's too out of focus and incorrectly saying a very low HFR rating. I've tried adjusting the sliders but I don't know how far to go? Also tried adjusting the 'crop' from 5% up to 30% but haven't used it yet as fog rolled in. Any suggestions? Also, it takes an age to do a focus routine. Like 10min or more. I'm thinking that's more due to the very slow transfer rates from the QSI583 than anything else!

2. This is the biggie. Once I've selected my target and framed it using the framing wizard. I assign a folder to save it in, select what filter, how many lights, exposure length etc etc. I open up PHD2 and connect everything. From my understand I should then be able to just press "Begin sequence" (or whatever it's called) and it should just run. The issue I'm having is that it'll correctly and accurately slew and centre the target using Pinpoint plate solving, run the (slow) auto focus routine but then it will just stop and initiate the end of sequence procedure and the fault "Guider failed to settle" will be displayed in the fault log. However it hasn't even tried to start the calibration for the guider? Or, when it does do the calibration it still says it's failed to settle and it'll stop. It's frustrating the hell out of me!

At the moment I have to manually centre it, do the auto focus, then manually calibrate PHD2 and begin guiding. Give it a few seconds to start guiding then proceed to begin the imaging routine. It works, but not how I want it to.

Any suggestions from other SGPro users would be helpful. Failing that I'll pop onto the SGPro forum and ask over there...but it's a big scary place and I don't know anyone! :(

Thank you in advance.
Phil

PS. If you need any kit info/image scale etc just let me know and i'll post it all up (image scale is 3.18!)

You need to tune the step size to the focuser, and this will vary quite a lot. For my refractor using the 490EX I use 75steps, but with the G4-16000 I have to use 250steps (remember the actual number will depend on the reduction ratio - mine is attached via a toothed belt onto the fine adjust wheel). If you're getting flat-ish lines or W shapes or whatever, make the step size more coarse - and extend the number of exposures to perhaps 15 until you understand how it behaves, then you can reduce it to the number that just gives you the curve around critical focus. You should be using 2x2 binnning to speed up downloads, but the exposure time will depend on the filter used. LRGB I use 5secs, narrow-band I use 15secs.

There is a setting under 'guider' for the settling time and the number of pixels it needs to stay within, the default (0.1 pixel IIRC) is a stupid number! Change it to something like 5 pixels for 1 second and it will be good to go.

ChrisH
Chris Heapy - current: 10-Micron GM2000HPS-II U/P, G11/Gemini, TV NP127is, Altair 8" RC, TV Genesis SDF, TV Pronto, SW Equinox 80ED, 10" LX200, 12" f/5.4 Newt, Vixen 90mm.
Atik 490EX, Atik EFW, Baader LRGB filters, Astrodon 3nM NB filters, Lodestar, QHY5L-II all-sky, Canon 70D and 350D
Whirley Obs., MPC Code Z89

Offline Phillyo

  • Poster God
  • *****
  • Posts: 1492
Re: More SGP questions
« Reply #3 on: 18:01:44, 02 November, 2015 »
Thanks Chris. I calculated my steps to be 53 I think but I'll redo it to check. What range of hfr do you get? Mine go from about 2 down to 1.? Then back up to 2. Should it be a greater difference? Like from 4 down to 1.? Depending on seeing then back up again?

I'll check the settings but I think I've done that. It just seems to not even try. Like it doesn't even begin calibration. Just gives up straight away :/

Phil
Astrotrac | Avalon Linear Fast Reverse with EQmod | WO Star 71 | Astrodon 3nm Ha, 5nm SII and 5nm OIII | Astro-modded Canon 450D | QSI 583wsg | Lodestar X2 Guidecam | Sequence Generator Pro | Pixinsight

Offline ChrisLX200

  • Poster God
  • *****
  • Posts: 2281
  • Macclesfield UK
Re: More SGP questions
« Reply #4 on: 18:27:08, 02 November, 2015 »
On a good night the refractor will go down to 0.5, but it will be between 0.6-0.8 usually. Starting point is 2.5-3.0 either side, and I use 14 steps (which is more than needed but I do have an offset between Astrodon NB filters and Baader LRGB filters so I cover the whole range. Yes, it takes a few minutes to run but I just ignore it and let it get on with it.

ChrisH

Chris Heapy - current: 10-Micron GM2000HPS-II U/P, G11/Gemini, TV NP127is, Altair 8" RC, TV Genesis SDF, TV Pronto, SW Equinox 80ED, 10" LX200, 12" f/5.4 Newt, Vixen 90mm.
Atik 490EX, Atik EFW, Baader LRGB filters, Astrodon 3nM NB filters, Lodestar, QHY5L-II all-sky, Canon 70D and 350D
Whirley Obs., MPC Code Z89

 

ukbuysellRemote Imaging from AustraliaSharpSkyblank APTUKAI on Facebook
Powered by SMF 2.0.13 | SMF © 2006, Simple Machines LLC
DarkBreak by DzinerStudio. Theme modified by The UKAI Team

Page created in 0.228 seconds with 38 queries.
TinyPortal © 2005-2012