Results 1 to 3 of 3
Like Tree1Likes
  • 1 Post By CamelHat

Thread: Re-aligning the guide scope and guide camera. Advice needed please.

  1. #1
    Leveye's Avatar
    Leveye is offline HYPER GIANT
    Points: 67,034, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!5 Threads Achievement!200+ Posts Achievement!
    Join Date
    Jan 2013
    Location
    Newport Oregon
    Posts
    8,984
    Points
    67,034
    Level
    100
    Thanks
    2,117
    Thanked 2,557x 2,243 Posts

    Default Re-aligning the guide scope and guide camera. Advice needed please.



    Ok this might be a silly question but it's 2016 and I want to tighten things up and do all the little things to my rig that need to be done. That includes refocusing my 9x50 160mm guide scope for tighter stars and better PHD2 tracking(check) and replacing the bracket on one of my main scopes that won't stay tight.(check) Now I must realign the guide scope to where it's pointing in the sky as opposed to the main imaging scope using a 3 way thumb screw design.

    My question is do I want the guide scope to be pointing in the exact same spot as the main scope and lined up perfect or should I avert it slightly? Say I center on a bright star and it's washing out all the available guide stars. Would that not cause an issue with guiding? I imaged all of 2015 with it slightly averted and no real issues but would like some advice from the experts out there. Many thanks and best of 2016 to you and yours!
    My eyes
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

    1984 Meade 2120 10" SCT- 1998 U.S.A. made Celestron C8 SCT -StellarVue SV80ED Doublet- 1960's Homemade 6" F5.6 Newt - Astro Tech AT8IN Imaging Newt- Vintage 1961 H.O.C. made ATCO 80mm/1200mm refractor w/ original vintage eyepieces - 20x70 Orion Little Giant II binoculars w/ original 1997 Virgo SkyMount Parallelogram-Zhumell, Orion, Astro Tech 9x50 finderscopes - Orion Atlas AZ/EQ-G iOptron Skyguider Pro Unmodded Canon 5DMKiii - Modded Canon 700D/ T5i- ZWO ASI178MC CMOS - Meade DSI II Mono CCD APT-DSS-PHD-CDC-PS-LR


    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  2. #2
    CamelHat's Avatar
    CamelHat is offline Bronze Supporter
    Points: 52,105, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    50 Posts Achievement!5 Threads Achievement!First 1000 Experience Points2 Posts Achievement20 Posts Achievement!
    Join Date
    Dec 2011
    Location
    Santa Barbara, CA
    Posts
    5,807
    Points
    52,105
    Level
    100
    Thanks
    1,170
    Thanked 1,719x 1,387 Posts

    Default Re: Re-aligning the guide scope and guide camera. Advice needed please.

    If your PA is perfect you can point the guide scope anywhere you want. If your PA is not perfect then you will get field rotation around the guide star. This may be a negligible amount compared to the field rotation of Alt/Az mounts where the PA is off by 90 degrees minus the observer's latitude. If the rule of thumb for Alt/Az mounts is 20-40 seconds for, say, 45 degrees latitude then being off by 1 degree (which is a lot for an EQ mount) is about 1/45th of that so, assuming some linearity in this issue, your field rotation should not kick in until 45 times 20-40 seconds, which is a long time. So I think there is quite some tolerance in this regard.

    (EDIT: Replaced "polar alignment" with "field rotation")
    Last edited by CamelHat; 01-03-2016 at 04:12 PM.
    Leveye likes this.
    ... Henk. Telescopes: 6" Mak-Newt (Comet Hunter), ES ED127CF, ES ED80, Zhumell Z12, Coulter Odyssey 10, AT6RC, Venture RX-7, Celestron Skymaster 20x80, Mounts and tripod: Losmandy G11S, AVX, LXD55, Tiltall, Cameras: Fuji X-a1, Canon SX40, Xt, XSi, T6, ELPH 100HS, DIY: Dob and camera barndoor trackers, afocal adapter, Dob with foldable base and Az/Alt setting circles, Accessories: SSAG, Plossls, Barlows, Telrad, laser collimators (Seben LK1, Z12, Howie Glatter), Cheshire, 2 Orion RACIs 8x50, Software: DSS, ImageMagick, PHD, Nebulosity, Photo Gallery, Gimp, CHDK

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  3. The Following User Says Thank You to CamelHat For This Useful Post:

    Leveye (01-03-2016)

  4. #3
    Leveye's Avatar
    Leveye is offline HYPER GIANT
    Points: 67,034, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!5 Threads Achievement!200+ Posts Achievement!
    Join Date
    Jan 2013
    Location
    Newport Oregon
    Posts
    8,984
    Points
    67,034
    Level
    100
    Thanks
    2,117
    Thanked 2,557x 2,243 Posts

    Default Re: Re-aligning the guide scope and guide camera. Advice needed please.

    Thank you for that info CH it helps a lot. I did a drift alignment in PHD2 not long ago and the mount is really aligned well right now. Unguided it will track a planet or the moon and keep it pretty centered for over an hour.
    My eyes
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

    1984 Meade 2120 10" SCT- 1998 U.S.A. made Celestron C8 SCT -StellarVue SV80ED Doublet- 1960's Homemade 6" F5.6 Newt - Astro Tech AT8IN Imaging Newt- Vintage 1961 H.O.C. made ATCO 80mm/1200mm refractor w/ original vintage eyepieces - 20x70 Orion Little Giant II binoculars w/ original 1997 Virgo SkyMount Parallelogram-Zhumell, Orion, Astro Tech 9x50 finderscopes - Orion Atlas AZ/EQ-G iOptron Skyguider Pro Unmodded Canon 5DMKiii - Modded Canon 700D/ T5i- ZWO ASI178MC CMOS - Meade DSI II Mono CCD APT-DSS-PHD-CDC-PS-LR


    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

 

 

Similar Threads

  1. Aligning new guide scope setup
    By josmith16 in forum Astronomy Forum
    Replies: 7
    Last Post: 03-30-2015, 07:22 AM
  2. Considering a guide camera upgrade - advice appreciated.
    By cmassa in forum Astro Imaging Forum
    Replies: 2
    Last Post: 02-15-2015, 03:11 AM
  3. Guide scope/camera advice
    By rgbtxus in forum Astro Imaging Forum
    Replies: 9
    Last Post: 12-04-2014, 10:02 PM
  4. Guide camera to use with Orion Mini 50mm Guide Scope
    By tnkumar in forum Astro Imaging Forum
    Replies: 4
    Last Post: 12-11-2012, 06:41 AM
  5. Looking for advice on a guide scope
    By Pitt in forum Astro Imaging Forum
    Replies: 4
    Last Post: 05-23-2010, 07:32 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Powered by vBulletin® Version 4.2.0
Powered by vBulletin®
All times are GMT. The time now is 01:41 PM.