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Old 12-01-2005, 10:17 AM
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mch62 (Mark)
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Join Date: Oct 2004
Location: Glenore Grove Queensland
Posts: 649
Yep Paul your right , my mistake it is only an EQ 1 or 2.
Don't go that scope with the small mount .
Paul is the EQ3 O.K. for that size scope .
You mentioned a few things to me about it that night.

Yes a dob is a good all round scope but if his main interest is PLANETARY than a good long focal ratio refractor on a EQ3 with a RA motor is a better choice.

You guys with dobs know what it is like trying to keep a planet in the FOV at high power.

But remember that an 80mm aperture is not going to give great visual views of deep sky objects unless you use the motor and a camera to take pics.

The max useful power for an 80mm is going to be 50-60X the objective diameter in inches.
So about 180-190X , although I have already pushed my 80mm grab and go to over that , but it is an ED lens and the night was good.

Have a look at Andrews Communications , his prices and range are very good.

You really have to think hard on , if you want to specialise on Planetary viewing or deep sky or both.

Aperture is not absolutely everything , quality and contrast is also very important in viewing the solar system.
The contrast of an unobstructed refractor is hard to beat .

You need a Newt with under a 20% obstruction ratio .

I have attached an image from my 80mm of Saturn , this was after the lens had dewed over but it gives you an idea of what to expect from that size. This is also an ED lens so it will be
relatively free of false colour as compared to and Achromatic lens.

Paul you have refractor , whats your thoughts on this for the planets?

Mark
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