Jump to content


This is good, right?

  • Please log in to reply
8 replies to this topic

#1 pdfermat



  • *****
  • Posts: 1077
  • Joined: 12 Nov 2007
  • Loc: Wisconsin

Posted 13 October 2013 - 10:42 PM

Right now, I'm writing this message from my living room, while my rig is tracking/autoguiding ngc 457. I must say, it feels weird "doing astronomy" without actually being outside.

I'm using TeamViewer to control my netbook next to the scope, and everything is finally coming together. I think I'm getting good results with my autoguiding, but I'd like some of you seasoned veterans to take a look:

Posted Image

Those red and blue lines are barely moving from the center line, but that's what I'm shooting for, right? I used the EQMOD polar alignment procedure to get everything dialed in, and I think it has had a positive result on my tracking.

Anyway - I'm having a blast moving the scope around from inside and watching the finderscope view from PHD. As they say - if you're having fun, you must be doing something right!

#2 gillmj24



  • *****
  • Posts: 4930
  • Joined: 06 Dec 2005
  • Loc: PA

Posted 13 October 2013 - 10:51 PM

Pic doesn't show up for me but sounds like you're doing good.

#3 pdfermat



  • *****
  • Posts: 1077
  • Joined: 12 Nov 2007
  • Loc: Wisconsin

Posted 13 October 2013 - 11:03 PM

Hmm...I wonder why the pic doesn't show for you? I'm using photobucket, and haven't had troubles in the past. I'll go to a different device and see I it shows up for me.

#4 blueman


    Photon Catcher

  • *****
  • Posts: 5555
  • Joined: 20 Jul 2007
  • Loc: California

Posted 13 October 2013 - 11:16 PM

The flat line DEC shows the polar alignment is good.
The RA looks fine, but without a clue of how large the movements are it is hard to tell for sure. But the RMS value looks good.


#5 orion69


    Viking 1

  • -----
  • Posts: 998
  • Joined: 09 May 2010
  • Loc: Croatia

Posted 14 October 2013 - 01:41 AM

If stars are good then everything is OK. PHD graph doesn't mean much since you are probably using finder for guiding (if mount is Atlas EQ-G).

#6 Mike X.

Mike X.

    Viking 1

  • -----
  • Posts: 824
  • Joined: 28 Jun 2010
  • Loc: Greece-Athens and Rome-Italy

Posted 14 October 2013 - 01:48 AM

I agree with Orion.
What focal lenght has the guide scope and at what FL do you immage?

This is what i get at 500mm guiding for example:
Posted Image
And gives me ok stars at 945mm FL immaging...Much depends also on what we think it is ok for us i guess.

If your stars are good than you don't have to worry ;)

#7 pdfermat



  • *****
  • Posts: 1077
  • Joined: 12 Nov 2007
  • Loc: Wisconsin

Posted 14 October 2013 - 08:03 AM

The more I read about PHD, I see that the graph is more of a qualitative tool than quantitative. In my case, it seems I should have a pretty flat graph unless something is drastically wrong, since I'm guiding with an Orion 8x50 finder (162mm focal length).

When I do decide on an imaging camera, I'll be imaging through my c8 with a f/6.3 reducer, so the imaging focal length will be around 1200mm. As you say, the real test will be if stars are round. I guess I'll have to wait and see!!

#8 orlyandico


    Fly Me to the Moon

  • *****
  • Posts: 5945
  • Joined: 10 Aug 2009
  • Loc: Singapore

Posted 14 October 2013 - 09:14 AM

PHD2 allows you to input the focal length and pixel size in um. Hence it can display the guiding graphs directly in arc-seconds.

Much more edifying. And you can change the scale. If your scale is +/- 1" even a Mach1 has an alarmingly jagged curve.

Posted Image

#9 snommisbor


    Viking 1

  • *****
  • Posts: 968
  • Joined: 15 Jun 2009
  • Loc: Cedar Park, TX

Posted 14 October 2013 - 10:25 AM

I was thinking that was really flat myself. I have an EM 200 and feel I get good polar alignment but my DEC is never that flat. Mine looks more like yours. I guide with a ST 80 and SSAG. Although sometimes it will guide perfect and other times it will be so finicky. Can be frustrating.

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics