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Out Of Culmination

Discussion in 'Beginner's Corner' started by Pleiades, Jul 4, 2018.

Out Of Culmination

Started by Pleiades on Jul 4, 2018 at 12:58 PM

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  1. Pleiades

    Pleiades Well-Known Member

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    Well, It's no real surprise. My XT6 is out of culmination. I have suspected it since my last viewing of Jupiter, and I guess it didn't exactly happen over night. I'm headed to Florida with a Refractor, so I don't have time to deal with it right now.

    When I return home, I have a little dust cap with a hole in the center and a shiny inside surface, that Orion provided me with to culminate the scope. It certainly works well enough for me to ascertain that I am out of sorts to begin with. After viewing videos on youtube, Orion went up another notch in my book for putting a little ring on the primary mirror for me. I wasn't looking forward to that procedure.

    I would like to ask my fellow AC skywatchers what they prefer for this procedure. I have heard of four methods:
    • Star culminating
    • Cheshire Culminating
    • Using a laser culminator
    • Using the pinhole cap with the shiny backside.
    Thanks in advance.
     
  2. Dave In Vermont

    Dave In Vermont Well-Known Member

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    The word you stumbled over is 'Collimation' or 'Collimate.' Anywho - the guide I'm link below is by Astro_Baby, from the UK, and is widely considered the best there is. I agree.

    And it centers on using the Collimation-Cap that you have. Here you go:

    Astro Baby's Collimation Guide.pdf

    Enjoy!
     

    Attached Files:

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  3. Nebula

    Nebula Well-Known Member

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    For my Newtonian I use a collimator cap and a Cheshire, no lasers. For regular maintenance, only the cap. I use the cheshire for the secondary mirror only, it has an edge over the cap for that task, I find.

    I learned with Astro Baby's guide has well very good document.

    Star alignment I never tried yet.. should do that, perhaps I could gain a few X of power on the planets with my telescope.
     
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  4. Pleiades

    Pleiades Well-Known Member

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    Well, that does make a bit more sense. I was figuring maybe the light had to culminate at the apex of the mirror, or something. It's now fully apparent that y'all have up and let a Tennessee hillbilly into the club. Well, to tell the truth Collimate, is a new addition to my vocabulary, so thanks for setting me straight. Also, thanks for the collimation information.
     
  5. Pleiades

    Pleiades Well-Known Member

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    I read over the guide, and it's very informative. I'll give it a shot when I get back into town. After reading the article, I'll use both my collimator cap, and a Cheshire tube. Thanks.
     
    Last edited: Jul 4, 2018
  6. Pleiades

    Pleiades Well-Known Member

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  7. Dave In Vermont

    Dave In Vermont Well-Known Member

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    Oh yeah. That's a Cheshire Sighting-Tube. But that's exactly what you need.

    One fair warning: The first-time you work on collimating your Newtonian, expect to be anxiety stricken and freaking-out! That's normal! :p But fear not! We all go through that. Then it becomes like riding a bicycle - second nature. You can't damage or destroy anything. You're just learning a new skill.

    I just use a laser, and it takes me about a minute. You'll be laughing at yourself in no time! :D

    And you've got us to help you when things look darkest. Soon you'll be the one helping someone else who's jumping out of their shoes.
     
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  8. Pleiades

    Pleiades Well-Known Member

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    Y'all have been awesome. My Orion has the centered ring pre marked on the primary mirror. Would I be better off with a laser?
     
  9. Dave In Vermont

    Dave In Vermont Well-Known Member

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    No. What you're doing is best, and more accurate, for the first time at least. Many stay with the collimation-cap. This will teach you the whats & whys you're doing this.

    That's my 2¢.
     
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  10. Orion25

    Orion25 Well-Known Member

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    And once your scope is in proper collimation, you can reach culmination in your observing! ;)
     
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  11. sickfish

    sickfish Well-Known Member

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    I use a cap for a quick collimation
    I also have a HoTech laser, I use this too.
    The laser is easy and does a really good job.
     
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  12. Gabby76

    Gabby76 Well-Known Member

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    The cap and Cheshire work the best and for a quick check when setting up the cap is the easiest way to check.
    I use a laser more for refractor focuser collimation than I ever did with a Newtonian.
     
  13. Nebula

    Nebula Well-Known Member

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    Astro Baby's Collimation Guide is by far the best guide I have ever found. Everything there is comprehensible nothing is useless, it's well written, simple with the right images easy to understand for the average user, not too much pages.

    It's a gift to be able write and create interest.

    She deserves a real gold medal for that comprehensible work for the people.

    http://www.astro-baby.com/
     
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  14. Nebula

    Nebula Well-Known Member

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    Wow I decided to collimate today, and I have seen better days. I must have 1 hours of work with the secondary now.. pretty sure the focuser needs a slight adjustment.

    If I decide to play with that, it might take the rest of the day.
     
  15. Pleiades

    Pleiades Well-Known Member

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    I'm now back in town, and weary from travel. I will not be collimating today. But tomorrow is forecasted to be rainy, so I'll brew the coffee and put on some Louie. :)

     
  16. Nebula

    Nebula Well-Known Member

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    Prepare yourself to take your time. :D

    The result of my latest collimation is amazing, the look of the stars is not the same anymore at higher power, the coma is not the same either. I think I was highly successful yesterday in improving my overall collimation to be able to reach higher power/quality.

    We will see more soon. (I had incredible views of saturn yesterday, 212x again, a bit of turbulence but I could see the quality was strong.

    I still think the cap and the cheshire sight tube are good together. To position the secondary roughly with the view of the entire primary inside. Then after the very precise tweaks of the secondary using the Cheshire which is much more precise then the cap. (I had to move my focuser a slight bit in order to get everything concentric)

    I swear to god, the stars are rounder now and I had an observation of the stars at 212x, with a sharpness I have never seen before., it looked like another telescope.

    I feel Mars will get the higher magnifications soon :):) 222x, 283x perhaps even more.

    When you're there, please tell us about your own collimation journey @Pleiades (and thanks for the jazz Youtube)
     
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  17. Dave In Vermont

    Dave In Vermont Well-Known Member

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    Line-up Polaris in your scope, Nebs. Then, at about 200X, defocus it and check the 'airy' disc image that results. What you're supposed to see are equally-spaced circular-lines. Perhaps referring back to Astro_Baby's guide. Or even a Google-search under such terms as 'airy-disc collimation.'

    Have a Happy-Algorithm!
     
  18. aeajr

    aeajr Well-Known Member

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    For my XT8 I have the collimation cap, combination site tube/cheshire tool and a Laser.

    I have used all three with good results. Today I mostly use the laser but I check from time to time with the cap to be sure they agree.
     
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  19. Pleiades

    Pleiades Well-Known Member

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    Yea. I am thinking i'll buy a laser as well. Mine is pretty darn close now. It made a huge difference. I check it by back-focusing stars now, and I'm getting perfect little doughnuts.
     
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  20. Dave In Vermont

    Dave In Vermont Well-Known Member

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    Pleiades -

    ScopeStuff down in Texas is an excellent place to find some exotic (and just plain weird!) items that Agena doesn't have. And their lasers are excellent. Jim - the owner (great guy!) - has a buddy who tweaks each one of these individually before affixing the label! And they arrive spot-on.

    http://www.scopestuff.com/index.html

    I find they're being adjustable in output to be an excellent improvement:

    http://www.scopestuff.com/ss_lcol.htm


    ss_lco3_L.jpg
    And at $44.00, a steal!

    Enjoy!

    Dave
     
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