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Old 13-01-2016, 07:47 PM
resurgance (Stewart)
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Location: Nelson, New Zealand
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Southern Hemisphere!!

Hi, thanks for having me, I'm all newly registered...

I am a novice, of a couple of years, have what I think is some decent kit, but still need to get back to basics. Permission to ask a bunch of questions??

Last night I gave up drift aligning again, just used the polar scope on my G11 and turned off my auto guider. Produced my best ever image of Orion. Have never had luck with AG, I suspect that although my mount's motors are tracking the right way, PHD2 isn't.

one of my challenges is that my G11 is non goto - digital drive; push-to. And every piece of software is either setup for GOTO and slewing, or instructions are for up north. Questions I have are along the lines of;

- If my camera (DLSR) is upside down on a right side up refractor, pointing West, then with my mount turned off, star trails should start heading down on my monitor right?

- Should my SSAG be right side up or upside down in relation to my refractor, given that the 50mm OTA it is on is a frac itself? Or is there a method of determining how PHD2 is reacting? Last night I tried to Drift align and the lines were pointed downwards, and the adjustment lines were frantically and constantly in the opposite direction, then it told me my mount was not reacting fast enough, even though it calibrated OK.

- To drift align being a Southy I want to start at my Eastern Horizon with hardly and DEC so OTA is pointing toward where the celestial equator meets east right? And this is to determine Azimuth? With my scope in the config mentioned above, which way do I adjust mount in relation to where my star drifts?

- Next I go overhead, to approx where Orion is at the moment, OTA still perpendicular to Celestial equator right? Then this is Altitude adjustment?

- Unguided I can do almost 120sec with rough alignment and still get nice round stars, as soon as I try auto guiding, its a jagged mess! I have ASCOM driver using shoestring GPUSB, as I thought there may have been an impedance issue with SSAG and ST-4 port on my DD. Results are no better.

I have Esprit 80mm Triplet, G11, SSAG, CentralDS cooled 600D, and another large scope that I'm not going near until I get things sorted.
Software; PHD2, PEMpro v3 beta and AstroART which I got to try Drift aligning in conjunction with PEMpro beta with new ASCOM driver since I have a DSLR - I can also try the SSAG but I don't like the larger pixel/sec on this for PEMpro as the goal was to get the PE as good as I could. I can't use PEMpro for polar aligning, because there is some software glitch that keeps not taking images after a promising start.

In a nutshell, I have an OVISION worm coming, and bought PEMpro to get my PE as low as poss - but first I have to figure to how to drift align as it seems this is the most fundamental aspect of AP.

End goal post alignment is to get PE as low as mount allows, then start guiding so I can get 3-5min exposures for the projects that I have in mind, and also maybe start using my big OTA one day.

Thanks for reading,
Stew
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  #2  
Old 14-01-2016, 12:23 AM
kens (Ken)
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Location: Melbourne, Australia
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Quote:
Originally Posted by resurgance View Post
Hi, thanks for having me, I'm all newly registered...
Welcome, Stew.
Quote:
Originally Posted by resurgance View Post
I am a novice, of a couple of years, have what I think is some decent kit, but still need to get back to basics. Permission to ask a bunch of questions??
Granted. That's what we're here for

Quote:
Originally Posted by resurgance View Post
- If my camera (DLSR) is upside down on a right side up refractor, pointing West, then with my mount turned off, star trails should start heading down on my monitor right?
No idea. Trying to work out things like that gives me headaches. I just do a little slew to see which way things move.
Quote:
Originally Posted by resurgance View Post
- Should my SSAG be right side up or upside down in relation to my refractor, given that the 50mm OTA it is on is a frac itself?
It should not matter. My guide camera was set up at around 45 deg upside down
Quote:
Originally Posted by resurgance View Post
Or is there a method of determining how PHD2 is reacting? Last night I tried to Drift align and the lines were pointed downwards, and the adjustment lines were frantically and constantly in the opposite direction, then it told me my mount was not reacting fast enough, even though it calibrated OK.
If you are drift aligning in PHD all guiding should be turned off. The built-in function should do that automatically. If you are not using the built-in drift align, turn off guiding pulses in the Brain. Make sure that tracking at sidereal rate is on though. The autoguider does not look after that
Quote:
Originally Posted by resurgance View Post
- To drift align being a Southy I want to start at my Eastern Horizon with hardly and DEC so OTA is pointing toward where the celestial equator meets east right? And this is to determine Azimuth? With my scope in the config mentioned above, which way do I adjust mount in relation to where my star drifts?
Drift alignment on a star near the horizon is for altitude. Azimuth adjustment uses a star near the meridian. If the graph is heading south you need to adjust north. Which way that is on the display depends on the orientation of your camera. Best to test beforehand by careful slewing in each direction. Or watch your calibration run to see.
Quote:
Originally Posted by resurgance View Post
- Next I go overhead, to approx where Orion is at the moment, OTA still perpendicular to Celestial equator right? Then this is Altitude adjustment?
No - that is for azimuth.
Quote:
Originally Posted by resurgance View Post
- Unguided I can do almost 120sec with rough alignment and still get nice round stars, as soon as I try auto guiding, its a jagged mess! I have ASCOM driver using shoestring GPUSB, as I thought there may have been an impedance issue with SSAG and ST-4 port on my DD. Results are no better.
Attach a PHD log file. The location is on the Global tab of the Brain. What version of PHD are you using?
Quote:
Originally Posted by resurgance View Post
End goal post alignment is to get PE as low as mount allows, then start guiding so I can get 3-5min exposures for the projects that I have in mind, and also maybe start using my big OTA one day.
PE or PA? PE=Periodic Error, PA=Polar Alignment
PE relates to errors in RA due to the drive train. PA errors result in drift in declination. Autoguiding is often the best way to eliminate PE. Polar alignment is important as even though autoguiding can eliminate the drift you get field rotation

Last edited by kens; 14-01-2016 at 12:27 AM. Reason: corrections
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Old 14-01-2016, 04:24 AM
resurgance (Stewart)
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Thanks Ken,

I'll work on a log file tonight, I am using PHD2, and down bottom of post I meant PE, by way of first sorting PA.

I have the older original stainless losmandy 2 piece worm block, I have not got to the stage where I can measure it using PEMpro, hopefully I can make that happen soon. Originally I thought my non-round stars were a result of this alone, but now I know it was several other things, so I ordered the OVISION worm in the meantime.

I was auto guiding and the AG was fighting the mount, also I had turned on PEC on the DDrive but without training it using hand controller - I had thought it was taking a reading itself not realising at the time that it had no way of knowing what the stars that the OTA was seeing were doing.

Now It will be an interesting exercise anyway to measure PE before and after the new worm.

BUT FIRST I must get PA sorted.

I was thinking of trying 2 sleeping - I get so tired on following work day, maybe I should sleep with the kids at 7 then get up at 11 and get cracking, back to bed at 3am.

Stew
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Old 14-01-2016, 04:45 AM
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pixelsaurus (Mike)
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Hi Stew,
Welcome to IIS and what he said. I live on the other island. Cheers.
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Old 14-01-2016, 06:27 PM
resurgance (Stewart)
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Nice one Mike! Over the moat.....

Thanks for the welcome. Mainly need more time out in the shed, the nights fly by too quickly!

Stew
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Old 15-01-2016, 08:47 AM
loc46south (Geoffrey)
loc46south

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Location: Milton - New Zealand
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Hi - Welcome to the group. You are at the start of a long journey and your problems won't go away in a couple of days unfortunately. If you want some help PM me at IIS and I will give you my email. I run 2 G-11's in and an astrophotography setup so I may be able to help you.

Cheers
Geof Wingham
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Old 17-01-2016, 07:55 PM
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ZeroID (Brent)
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Hi Stewart, Welcome to the growing Kiwi contingent on IIS. I'm up in Jaffa land fighting with the Light Pollution and still learning on the slippery expensive slope of astro-imaging.
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Old 18-01-2016, 04:33 AM
resurgance (Stewart)
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Hi Brent, thanks! I did live there many a moon ago
Is quite good being in contact with people in our neck of the woods; The other forums seem like they are a world away when it comes to gear and aspects like pointing to a completely different pole....
Stew
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