Finder scope

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Finder scope

Postby Chewie2309 » Thu May 17, 2018 7:39 am

Hi all I’m very new to this and this might seem like a really stupid question ,right I’ve noticed when I switch my finder scope on red dot appears so I fix this to a point but if I move my head to a different position the red dot has moved and is nowhere near the first point I looked at so theirfore the scope is out as well how do I make sure the red dot is in the same place every time I look through the finder scope (said it was stupid ) thanks
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Re: Finder scope

Postby Aratus » Sun May 20, 2018 6:16 pm

There is a certain amount of leeway with 'red dots'. When initially aligning the device, try to get the red dot, and the object you are aligning with, in the centre of the circle formed by the ring you are looking through. Later, when lining up with with a target, you will always know to move your head until the dot is in centre of the circle. - then move the telescope until dot and object are in the centre of that circle. That should give much better accuracy.

Someone should come up with device that slightly illuminates the edge of the display circle to avoid this parallax problem.
I use an 11" Celestron SCT (CPC 1100) on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI1600MC and Canon 500D for imaging.
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Re: Finder scope

Postby Gfamily2 » Sun May 20, 2018 6:48 pm

Meade RDFs don't have a look-through circle, so there's less of an issue.
Scopes: Meade 8" SCT, Skywatcher 127mm Mak, Raffle winner of SW ST80
For imaging: Pentax K5, Asda webcam, Star Adventurer (new toy)
For companionship: Mid Cheshire Astronomical Group.
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Re: Finder scope

Postby Aratus » Mon May 21, 2018 9:59 pm

The 'look through circle' is the means of keeping the eye centered with the central axis. Some RDFs don't have such a tube, (like the latest Meade) but that can't help the parallax problem by itself. In those cases the glass is nearer to the eye, and people tend to use both eyes, with one looking through the finder glass. It is worth trying that even if the finder has a circle. It also helps to focus the eyes on the stars and not on the red dot.
I use an 11" Celestron SCT (CPC 1100) on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI1600MC and Canon 500D for imaging.
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Re: Finder scope

Postby The Man with the Corrugated Iron Roof » Sat Jun 02, 2018 9:21 pm

I find a decent finderscope is better. I have a Skywatcher 9x50 right angle one and it is great!
How can I be one with the universe when we don't know what 96% of it is.

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