Results 1 to 6 of 6
  1. #1
    hallcp's Avatar
    hallcp is offline White Dwarf
    Points: 7,805, Level: 61
    Level completed: 85%, Points required for next Level: 45
    Overall activity: 0%
    Achievements:
    First 1000 Experience Points365 Days+ Registered Achievement!750 Days+ Registered Achievement!1000 Days+ Registered Achievement!2 Posts Achievement
    Join Date
    Feb 2009
    Location
    north carolina
    Posts
    25
    Points
    7,805
    Level
    61
    Thanks
    0
    Thanked 1 Time in 1 Post

    Default Question about Polaris viewfinder



    I picked up an illuminated reticle finderscope for a Meade LXD75 equatorial mount off eBay. I am hoping to mount it on my fork-mount SCT somewhere to help me get polar-aligned. The reticle has an etching of the little dipper, Polaris and the celestial pole.

    My question is about how you use this gadget. It would seem to me that you would have to rotate it to match the stars at a given hour of the night. But the mounting bits that came with it give no hint of that. It's all hex screws and very fixed-looking stuff.

    The downloadable manual for the LXD74 from Meade glosses over most of this.

    Could someone describe the general process of setting up and using such a finderscope? I feel like I may be missing something.

    Thanks!

    Charles Hall
    total newbie
    Raleigh, NC

  2. #2
    Vinnie's Avatar
    Vinnie is offline Guest
    Points: 24,260, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    Got three Friends20+ Friends Achievement!First 1000 Experience Points5+ Referrals Achievement!100+ Threads Achievement!
    Join Date
    Sep 2008
    Location
    Queensland, Australia
    Posts
    3,474
    Points
    24,260
    Level
    100
    Thanks
    41
    Thanked 683x 362 Posts

    Default

    I have no idea how you would get around that one Charles

    The Polar Scope is indeed intended to be rotated to match date and time, but its also intended to be mounted in a dedicated housing which is in the central bore of the RA axis on a given German Equatorial Mount, in this case an LXD 75

  3. #3
    hallcp's Avatar
    hallcp is offline White Dwarf
    Points: 7,805, Level: 61
    Level completed: 85%, Points required for next Level: 45
    Overall activity: 0%
    Achievements:
    First 1000 Experience Points365 Days+ Registered Achievement!750 Days+ Registered Achievement!1000 Days+ Registered Achievement!2 Posts Achievement
    Join Date
    Feb 2009
    Location
    north carolina
    Posts
    25
    Points
    7,805
    Level
    61
    Thanks
    0
    Thanked 1 Time in 1 Post

    Default

    Well, it's not a big deal to make an external finderscope mount (it may not be pretty!).

    But my specific question is: does the finderscope have to rotate? And does it rotate in real EQ mounts like the LXD75?

    Thanks!

    I also appreciated the other polar alignment links you posted elsewhere. Precise polar alignment feels like a pretty tall order for a beginner like me, but I want take pictures.

    Charles.

  4. #4
    hallcp's Avatar
    hallcp is offline White Dwarf
    Points: 7,805, Level: 61
    Level completed: 85%, Points required for next Level: 45
    Overall activity: 0%
    Achievements:
    First 1000 Experience Points365 Days+ Registered Achievement!750 Days+ Registered Achievement!1000 Days+ Registered Achievement!2 Posts Achievement
    Join Date
    Feb 2009
    Location
    north carolina
    Posts
    25
    Points
    7,805
    Level
    61
    Thanks
    0
    Thanked 1 Time in 1 Post

    Default

    Vinnie, you may have answered my question already... so pardon that reply above; but since I've never seen this mount up close I'm not sure. I believe you're saying that the finderscope I have is firmly mounted in some other rotating element within the mount.

    Is that it?

    Thanks.

  5. #5
    DizzyGazer's Avatar
    DizzyGazer is offline Guest
    Points: 19,030, Level: 95
    Level completed: 33%, Points required for next Level: 270
    Overall activity: 0%
    Achievements:
    Got three Friends20+ Friends Achievement!First 1000 Experience Points5+ Referrals Achievement!100+ Threads Achievement!
    Join Date
    Nov 2008
    Location
    Concrete, Washington USA
    Posts
    1,428
    Points
    19,030
    Level
    95
    Thanks
    352
    Thanked 236x 178 Posts

    Default

    Hi Hall,

    Here is a video on Polar Scope alignment that I found helpful:

    [ame="http://www.youtube.com/watch?v=wh5kipL1mPA&feature=channel_page"]YouTube - HEQ5 PRO Polar Scope Calibration[/ame]

    To be honest, I've never even used mine..I just do a good alignment with Polaris and the mount tracks real well. When doing AP work the polar scope is much more critical, but for general star hopping and observing a decent alignment with Polaris is sufficient.

    Mike

  6. #6
    hallcp's Avatar
    hallcp is offline White Dwarf
    Points: 7,805, Level: 61
    Level completed: 85%, Points required for next Level: 45
    Overall activity: 0%
    Achievements:
    First 1000 Experience Points365 Days+ Registered Achievement!750 Days+ Registered Achievement!1000 Days+ Registered Achievement!2 Posts Achievement
    Join Date
    Feb 2009
    Location
    north carolina
    Posts
    25
    Points
    7,805
    Level
    61
    Thanks
    0
    Thanked 1 Time in 1 Post

    Default

    THANKS! Between Mike's video link and the links Vinnie posted in another thread ("Astro Baby's HEQ5 Polar Alignment), and I can see I had several misconceptions. #1 was that the viewfinder was attached to the tripod head, it's actually attached to the axle on which the telescope swings. #2 was that the little star map in the reticle is NOT an actual overlay for what you'll see through the viewfinder, the little dipper is not going to be in the viewfinder field of view when you use it.

    I think also that all these alignment dials and date/time calculations are a mechanical analog of the polarfinder.exe program I found on the web.

    This was all extremely helpful.
    Last edited by hallcp; 04-03-2009 at 08:44 PM.

 

 

Similar Threads

  1. ORION XT10 Viewfinder help
    By serialmike in forum Orion Telescopes Forum
    Replies: 13
    Last Post: 06-11-2012, 03:18 PM
  2. Looking at the viewfinder in detail
    By Dublin sky watch in forum Telescope Accessories Forum
    Replies: 10
    Last Post: 01-15-2010, 10:26 PM
  3. Question about Polar Viewfinder usage
    By hallcp in forum Telescope Eyepieces Forum
    Replies: 12
    Last Post: 04-13-2009, 12:13 AM
  4. viewfinder magnification
    By miso@sushi.com in forum Amateur Astronomy Forum
    Replies: 8
    Last Post: 03-18-2005, 03:24 AM

Tags for this Thread

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 02:46 AM.