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Need help collimating!!!!!


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I've had my scope since Christmas and I've heard that all well collimated scope performs a lot better. I've noticed now that my mirrors aren't perfectly aligned and the image i get through the scope are blurred. I have been reading tutorials but i don't understand. I don't have a Cheshire or a collimation cap but i need to collimate my scope. Please help :)

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Chesire gr8 tool for sortn out ur secondary mirror thn if u cn get sortd with lazer collimater ur good to go.........is ur primary mirror centre spotted yet you'll need to do this to get it as accurate as possible 

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I've just spent 30 minutes messing around with the adjustment screws on the primary mirror to centre the spot, i have it centred near enough but not perfect. Will this still effect my viewing if its not perfect?

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16 minutes ago, Yamez said:

I've just spent 30 minutes messing around with the adjustment screws on the primary mirror to centre the spot, i have it centred near enough but not perfect. Will this still effect my viewing if its not perfect?

Does your primary mirror have a centre spot marked on it? If not you will have to put one on yourself.

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Hhmmm! It seems that you are lost in the jungle.

First of all: stay cold; second: stay cold; third: stay cold.

Quote

 the image i get through the scope are blurred.

it doesn't says nothing !
You must tell what telescope, what eyepiece. Trade mark is important.

You say your scope is out of collimation. Let check it better:

1. use your minor focal length eyepiece. 6 mm for example. If you have only around 9 - 12  mm use together a barlow.

2. focus a bright star (try to choose a non binary star sistem) in the center of the field view.

3. move focus out, only a little, to see the concentric circles like the photo below.

gso305-extrafoco.jpg

if the black center is out of center and the circles aren't concentric... you need collimate the telescope.

4. do it now with inner focus and see the concentric circles like the photo below.

if the black circle in the center is out of center  and the circles aren't concentric ... you need collimate the telescope.

gso305-intrafoco.jpg

Only after these tests you can say: my scope needs collimation.

And if you needs to collimate the telescope DO NOT TRY ADJUST THE SECONDARY MIRROR  without at least a Cheshire.

You can do adjust of the primary mirror to get the concentric circles as showed above, although.

You have 3 screws at the botton that do it. You need only patience. The rule is very simple:

1. if the black center is out of center try to find the screws that move the star to the direction of the error. Re-center the star in the field of view (moving the tlescope RA and DEC) and check if it is in better shape and position.

2. maybe you must work with 2 screws. You don't need to work with 3. Let one of them as it is.

note: the photos above were done with webcam. The image is bigger than you will see with your eyes. The important is analyse the concentric circles and the centralizatoion of the black circle. Do extra and intra focus only to get that visualization.

Edited by jsmoraes
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2 hours ago, Knighty2112 said:

Does your primary mirror have a centre spot marked on it? If not you will have to put one on yourself.

My primary does already have a center spot on it.

 

16 minutes ago, jsmoraes said:

Hhmmm! It seems that you are lost in the jungle.

First of all: stay cold; second: stay cold; third: stay cold.

it doesn't says nothing !
You must tell what telescope, what eyepiece. Trade mark is important.

You say your scope is out of collimation. Let check it better:

1. use your minor focal length eyepiece. 6 mm for example. If you have only around 9 - 12  mm use together a barlow.

2. focus a bright star (try to choose a non binary star sistem) in the center of the field view.

3. move focus out, only a little, to see the concentric circles like the photo below.

gso305-extrafoco.jpg

if the black center is out of center and the circles aren't concentric... you need collimate the telescope.

4. do it now with inner focus and see the concentric circles like the photo below.

if the black circle in the center is out of center  and the circles aren't concentric ... you need collimate the telescope.

gso305-intrafoco.jpg

Only after these tests you can say: my scope needs collimation.

And if you needs to collimate the telescope DO NOT TRY ADJUST THE SECONDARY MIRROR  without at least a Cheshire.

You can do adjust of the primary mirror to get the concentric circles as showed above, although.

You have 3 screws at the botton that do it. You need only patience. The rule is very simple:

1. if the black center is out of center try to find the screws that move the star to the direction of the error. Re-center the star in the field of view (moving the tlescope RA and DEC) and check if it is in better shape and position.

2. maybe you must work with 2 screws. You don't need to work with 3. Let one of them as it is.

note: the photos above were done with webcam. The image is bigger than you will see with your eyes. The important is analyse the concentric circles and the centralizatoion of the black circle. Do extra and intra focus only to get that visualization.

Thank you, i did the tests and i could tell that it needed collimating so i started to play around with the screws i got it in the center maybe not perfect but when i get a chance i will sure invest in a chesire.

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Quote

i got it in the center maybe not perfect

Don't worry. The absolute perfeciton is relative. Refraction of atmophere can confuse. The positon of telescope can cause flexure and thus little misalignment.

Perfection is the goal ... only the goal !

Edited by jsmoraes
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I found that a colli cap works better for me than a Cheshire for sorting out the secondary. I use the Cheshire only for the primary. I'm assuming that you're using a Dob so here's a few linkies that helped me out.

http://www.cloudynights.com/page/articles/cat/articles/collimation-and-the-newtonian-telescope-v4-r2599

http://www.propermotion.com/jwreed/ATM/Collimate/Chesire.htm

http://www.viewfromascope.com/how-to-collimate-a-telescope/

http://www.andysshotglass.com/Collimating.html

 

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