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Old 15-11-2007, 07:21 PM
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Marko of Oz (Mark)
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Do polar scopes have magnification?

Or are they just 1:1 sorta thing?

I have a Skywatcher EQ6 basic mount with an illuminated polar scope. I've never tried to use it because I can't see Octans from my yard let alone the asterism due to sky glow from the local meatworks. But if there's some magnification in the polar scope then maybe I should try it.

I'm asking rather than trying it because there's no telling when I'm going to get another clear night.
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Old 15-11-2007, 09:47 PM
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vash (Ashley)
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I'm not sure if it does, I've never really thought about it, I you wanted to find out though just look through it during the day at a target, if it appears larger than your naked eye then I would say that it does magnify
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Old 15-11-2007, 09:49 PM
Dennis
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I think that my Vixen GPDX PAS is x6 mag with a 21mm objective lens?

Cheers

Dennis

(PAS=Polar Alignment Scope)
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Old 16-11-2007, 08:23 AM
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By definition: Polar Alignment Telescope.
Yes it does have magnification, around 5x with an 18mm objective.
It has to be collimated with the RA rotational axis. So don't go mucking about with its collimation screws.
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Old 16-11-2007, 01:19 PM
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g__day (Matthew)
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What I wish is that Southern Hemisphere polar scopes had greater apperature for improved light reach! On mine illuminated one I can't the finder circles unless illumination is on - and with illumination on I can't see the stars around Sigma Octans! I wish it was a 50 mm diameter polar scope!
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Old 16-11-2007, 05:18 PM
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It is hard to fit a 50mm aperture Polar Alignment Telescope into a 40mm shaft!
If you hold a variable torch at an angle to the front port of the PAT, by varying the angle you can increase and decrease the amount of background red glow so that the reticle can be seen at the same time as the stars of Octans
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Old 16-11-2007, 07:56 PM
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g__day (Matthew)
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Wish they had a larger lens outside the shaft -say a cone shaped refractor that protruded 6" - 8" past the mount rather than flush - and was at least 50mm - tapering to say 20mm inside the head!

That would be great - fit it - align, remove it - go!
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Old 03-12-2007, 10:39 PM
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Marko of Oz (Mark)
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Thanks for the replies/info. I finally got to have a go with the polar scope last night. After leveling the tripod and doing a rough alignment with a compass allowing for my umm "magnetic declination" I think it's called, I peeked through the polar scope and could see a few very dim stars.

I looked in Starry Night to see the orientation of the asterism and after 10 minutes of looking through the polar scope it dawned on me that it was all reversed, backwards, upside down and inverted sooooo I turned the notebook upside down to get the upside inverted about face angle of the asterism. And finally, after about 30 mins of twiddling and tweeking, turning the illuminated thingie up n down, getting dirty hands, knees, cramps n such I had some polar alignment happening. I guess I should have marked on the ground where the tripod legs were for next time

Anyway, it was nice to be able to capture 3 minute avi's and still have the subject in the field of view even with the 5x powermate in.

cheers

Mark

Last edited by Marko of Oz; 03-12-2007 at 10:42 PM. Reason: typos
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  #9  
Old 03-12-2007, 11:05 PM
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Quote:
Originally Posted by Marko of Oz View Post
I looked in Starry Night to see the orientation of the asterism and after 10 minutes of looking through the polar scope it dawned on me that it was all reversed, backwards, upside down and inverted
cheers
Mark
Hi Mark, for the record, the image you get through the polar scope is not reversed or inverted. Being a lens system only, the image is rotated upside-down 180 deg, but NOT mirror-image inverted vertically or horizontally. The easiest way I find to roughly pre-align the polar scope recticle, is to find the Octans pattern in 7x50 bino's first, then rotate the PAS recticle Octans pattern so it is 180 deg upside down relative to the image you got in binoculars. It's a 'sinch' once you get the hang of it a few times. Cheers, Fox
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Old 03-12-2007, 11:09 PM
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ballaratdragons (Ken)
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Quote:
Originally Posted by g__day View Post
What I wish is that Southern Hemisphere polar scopes had greater apperature for improved light reach! On mine illuminated one I can't the finder circles unless illumination is on - and with illumination on I can't see the stars around Sigma Octans! I wish it was a 50 mm diameter polar scope!
Roger has already commented on how I do it. I use a very low light red torch and angle the light into the front opening. I can see the Octans trapezium stars AND the printed star pattern this way
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