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Dob collimation and alignment

Discussion in 'Astronomy Gear' started by Karen, Aug 1, 2017.

  1. Karen

    Karen Well-Known Member CAS Member

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    Help please. My 8'' dob is out of alignment. When I use the scope I need to move the barrel about 10 centimetres to the right to focus on an object. I went online for some help to do it myself, but I don't feel competent enough. I will be at the Observatory on Members night August 19. Would someone kindly collimate it for me and show me any tips and hints that will help me to do it in the future. I have been very careful not to bump it, but I guess it has moved a bit while transporting in the car.. All help gratefully accepted.
     
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  2. Heather Skinner

    Heather Skinner Well-Known Member CAS Member

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    I am sorry but I have never collimated my scope, but, are you sure it is collimation, and not the finder-scope that needs to be re-aligned? You could get a bright star in the middle of your eyepiece, -main scope, and then, use the little adjustment screws of your finder,-[ there are three of them, one is to hold the finder-scope, the other two will adjust the finder] give those a tweak until the bright star you see in the middle of your eyepiece, is also in the middle of your finder... It is very easy to knock the finder out a bit... Be patient as the bright star in your eyepiece of your scope will drift a bit, nudge your scope until it is again centred in the middle, and go back to your finder to tweak your adjustment screws until the bright star is in the middle of both your eyepiece, and, your finder.. If that is all that's the problem, very easy to fix... Hope I didn't make it sound complicated..... I find scopes not only a joy to use, but also, they can be a right pain in the whatsit! In that case, I will get out my bino, --simple to use, and a joy to see the beautiful open clusters... If I am at the observatory on that night, I can help you with the finder, if that is the problem...(y)
     
  3. Gary Steel

    Gary Steel CAS President CAS Member CAS Committee

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    Hi Karen. If you are out on members night, there should be someone able to give you a hand. I can certainly have a look at it, although there is likely to be someone more knowledgeable than me.
     
  4. CAS Admin

    CAS Admin Administrator CAS Member CAS Committee

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    And you don't have to wait that long. Any clear night will usually find someone at the observatory.
     
  5. Karen

    Karen Well-Known Member CAS Member

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    Thanks Heather and Gary, I feel such a newbie with my scope. What I have been doing is lining up an object with the crosshairs, then looking through the eyepiece and adjusting the focus screws if necessary, have not had a problem until now. After your reply. I looked at my scope and saw two screws on the finder scope, I have just twiddled the black ones on the finder scope and found they moved a little,I have never touched them before . I am such an amateur and unsure of fiddling with things that I am unsure of. An instruction manual on what does what would be helpful. So the next clear night I will take it outside and try to align it that way. I was puzzled as to why, when I had something was perfectly aligned in the crosshairs and I looked through the the eyepiece and saw nothing and moving the barrel was the only way to bring it into view. Hopefully with your advice I will be able to fix the problem, it is very possible that I knocked the finder scope, as though the telescope is not heavy to carry, it is rather awkward, but I love my scope and it is uncomplicated for a beginner like me. I was told that 8'' dobs rarely need collimation, and it's simplicity in operation was what appealed. Am not sure if I can get out to West Melton before Sat.19, have had car problems, but will definitely be at the monthly meeting. I will certainly appreciate any help and advice on using my scope and knowing what knob does what. Whew!!!!!!!!
     
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  6. Karen

    Karen Well-Known Member CAS Member

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    EUREKA!!!!!!!!! Thanks a million Heather, I couldn't wait to try your advice, it's clear outside, so I followed your instructions, and I had obviously unknowingly bumped the finder scope. It's all aligned now. Did it looking at Jupiter, the four moons aligned look fantastic. I feel a bit silly not even noticing the screws on the finder scope, so it's all a learning curve of not trying to run before I can walk. Have also googled 8'' dob and found good instructions on where everything is and what it does. See you at the members meeting, not sure if I can get out to the Observatory before then. Thanks again
     
  7. Dale kershaw

    Dale kershaw CAS Editor CAS Member CAS Committee

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    It is great to see the forums are working with helping folks with any issues and suggestions
     
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  8. CAS Admin

    CAS Admin Administrator CAS Member CAS Committee

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  9. Heather Skinner

    Heather Skinner Well-Known Member CAS Member

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    It is Very easy to give the finder a knock, also, I should have said, during the day, you can give the finder a tweak; line up your scope/eyepiece on a target, top of chimney, pointy bit of roof or whatever, and then tweak your finder until object is in the middle of both finder and, eyepiece, remember, the object will be up-side-down; this may be better, as, there will be no drift.. Perhaps not lined up on the corner of someone's window,--ha--ha.. No need to feel silly, you wouldn't guess the things I didn't know, and said when learning about my new scope; let's say, people were understanding, and, smiled a lot,-out of pity I think! I still have some problems with it at times. Though when I Do get targets, they are super sharp,-- but,you can't beat a Dob...
     
  10. Heather Skinner

    Heather Skinner Well-Known Member CAS Member

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    Gary, just a thought,- [ouch that hurt] there is a 5inch scope at the observatory similar to mine I think? and, I think it is a Newtonian? Just wondering, if it would be easier to find objects for me using a Newtonian, than my scope with the eyepiece at the end of the scope. When I got the scope, I thought it would go Exactly to the target, not, close too which is a problem to me. I have to laser the target to try and find it if, I can. I find it fiddly and awkward, and, anyone imaging does not appreciate it much.. I swing my dob around and locate stuff much easier with the eyepiece at top... Wondering, how the [observatory] Newtonian would be to handle if it could be put on an altaz mount??? What you think? Possible???? :confused:
     

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