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Classic Telescope Testing

beginner classic collimation optics refractor
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#101 DMala

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Posted 07 January 2019 - 02:34 PM

It sounds interesting but I am not clear on one aspect. I assume Allan's telescope lenses were well collimated. Now the collimations screws have been slightly twisted to center the interference rings. What happened to the initial collimation? Wouldn't a star test to verify collimation be warranted now?

#102 DAVIDG

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Posted 07 January 2019 - 02:58 PM

 No,  it is not the collimation screws he turned but the screws that hold the retainer ring on.  To do the test, the lens in it's cell is removed from the telescope and your adjusting the retainer ring of the cell. Adjusting the air gap is independent of collimating the objective.

 

              - Dave 


Edited by DAVIDG, 07 January 2019 - 03:01 PM.

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#103 AllanDystrup

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Posted 07 January 2019 - 03:00 PM

DMala,

 

     The 3 screws I’m adjusting for centering the interference pattern are the small screws in the lens retaining ring (not the 3 screws in the “ears” of the lens cell for collimating the cell to the tube/focuser). The screws in the retaining ring presses down in 3 points on the front lens, thus adjusting the tilt/spacing between the front and rear lens.

 

     — Allan


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#104 DMala

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Posted 07 January 2019 - 03:36 PM

Got it thanks


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