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Adding reticle illumination to Celectron polar scope?

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#1 TelescopeGreg

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Posted 12 July 2020 - 04:46 PM

Hi folks,

 

Quick question, before I try to (re) invent a wheel...  I have an AVX mount with its polar alignment scope installed.  The reticle on the polar scope is not illuminated, and holding a red flashlight out in front of the scope interferes with it.  As I move the flashlight around the periphery, the position of Polaris on the reticle moves considerably, making an accurate alignment difficult.

 

Is there an easy way to add illumination to the PAS?  I'm thinking a couple of small LEDs around the rim, but I also need it to be removable so that I can look through the empty mounting hole for coarse alignment purposes.  Has anyone created such a "crown"?

 

Thanks,

 

Greg

 



#2 Paul Skee

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Posted 12 July 2020 - 05:57 PM

I found this is the classifieds. I bought one. Haven't had it out yet, but tried it inside a dark room and it seems like it just might do the job!

https://www.cloudyni...pe-illuminator/


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#3 Spectral Joe

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Posted 12 July 2020 - 08:46 PM

The image of a star on a reticle properly focussed should not move regardless of conditions. The basic test for this is to move your eye back and forth while looking through the finder, the star image should not move relative to the reticle. If it does, the distance from the objective to the reticle is incorrect, and that needs to be fixed before anything else.

 

Joe



#4 dmcnally

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Posted 12 July 2020 - 09:05 PM

I used a PVC plumbing tee and a free Harbor Freight flashlight.  I put a piece of cardboard, with a small hole with a red filter, in front of the flashlight to adjust the intensity of the light.  It worked great.

 

polar.jpg

 

 

Clear skies,

Dave


Edited by dmcnally, 12 July 2020 - 09:14 PM.

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#5 TelescopeGreg

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Posted 12 July 2020 - 11:55 PM

The image of a star on a reticle properly focussed should not move regardless of conditions. The basic test for this is to move your eye back and forth while looking through the finder, the star image should not move relative to the reticle. If it does, the distance from the objective to the reticle is incorrect, and that needs to be fixed before anything else.

 

Joe

Yeah, I understand.   The flashlight is the Celestron FireCel.  I believe what's happening is that I have to move the cover of the flashlight into the field of view of the scope, and its lens is diffracting / refracting the view.  Moving my eye doesn't change things; it's definitely the movement of the flashlight.

 

I used a PVC plumbing tee and a free Harbor Freight flashlight.  I put a piece of cardboard, with a small hole with a red filter, in front of the flashlight to adjust the intensity of the light.  It worked great.

Ha!  Interesting idea.  Basically you're letting the light from the flashlight "splash around" the insides of the pipe, eventually making their way into the scope.   Because the pipe is all outside of the field of view, I wouldn't have the issue with the flashlight lens.

 

I'm quite sure I've got a spare "T" in the sprinkler parts box.  Thanks!


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