collimation

[shyam]

Hello

a very good day to all out there. As the Rainy season getting over in my part of kerala in India.Now i have started to get along with the telescope  celestrone astromaster 114 eq. Now while doing collimation i could see in the eye peice two objects one the primary and with that spider with a small dougnut kind of thing. Now my doubt is when the barlow correcting lens removed and seen through the eye peice i can see my eye is it correct ? bit of confusion after a long gap . Now when lookin through the eyepiece installed in normal state, am i seeing the object in the dougnut thats where i saw my eye when barlow removed .

thanks

shyam menon

[happy-kat]

Hi

Is there telescope about 500mm long? I think if you have the telescope with the lens built into the focuser collimation is different to standard procedure. There's a post somewhere on how to check it I might find it later.

[Dave In Vermont]

Yes - look down the focuser and look if there there's a glass lens there?

Thanks!

Dave

[shyam]

hi

there is a lens inside the focuser tube

thansk

shyam menon

[John]

The best way to check and adjust the collimation with that type of scope is by star testing and using a simple collimation cap. Here is a thread from another forum by someone trying to collimate the same scope that you have:

https://www.cloudynights.com/topic/440568-trying-to-collimate-my-bird-jones/

 

[Ricochet]

When you say "eye piece" do you mean an actual eyepiece with lenses in it or do you mean some sort of collimation tool or even just the focuser? If you are looking directly into the focuser then it is normal that you would see the reflection of your eye with the corrector lens removed. With the corrector lens inserted I would think that you should still be able to see the reflection of your eye, but because the focal length is doubled the reflection will be much smaller. With this type of scope collimation should be as "simple" as getting the reflection of your eye centred and all the circles that you can see (bottom of the focuser, primary and secondary mirror edges) concentric.

 

[happy-kat]

These are two related reads if you need further reading. Hope you get your colllimation sorted.

link 1

link 2

[shyam]

2 hours ago, Ricochet said:

When you say "eye piece" do you mean an actual eyepiece with lenses in it or do you mean some sort of collimation tool or even just the focuser? If you are looking directly into the focuser then it is normal that you would see the reflection of your eye with the corrector lens removed. With the corrector lens inserted I would think that you should still be able to see the reflection of your eye, but because the focal length is doubled the reflection will be much smaller. With this type of scope collimation should be as "simple" as getting the reflection of your eye centred and all the circles that you can see (bottom of the focuser, primary and secondary mirror edges) concentric.

 

Thanks dear , Good Info