Astronomy

A Good Mount for my Telescope



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"A Good Mount for my Telescope"
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The first time I used a CG-4 mount was in conjunction with my first telescope, it was many years ago and I lacked the experience to really get the most out of it, in fact my initial frustrations with it started me off on a long love affair with the Dobsonian style of mount (big reflector telescopes on a simple and intuitive wooden mount) and put me off using any EQ mounts for a long time.

It was years later that I finally invested the time and patience to use the mount effectively.

When I was younger I was incredibly hasty and often rushed into things without careful preparation. The first night out with the mount and I literally just plopped it down in the garden, mounted my telescope on it and expected to be effortlessly touring the heavens within seconds, this was far from the case as it turned out.

With all equatorial mounts you have to go through a nightly ritual before starting your observations, first you must find North and line the arrow on the mount up exactly in that direction. You must then adjust the tripod legs via three turnable nobs near the bottom of the legs so that the mount is level, a spirit bubble on the side of the mount will let you know when the mount is levelled correctly.

You must then adjust the mount with two metal pegs so that the latitude scale matches the latitude of your location (for me it is 51 and a half degrees) and make adjustments in azimuth with two black plastic nobs until the Polaris star (which is only half a degree off of true polar North) is centralised in the polar finder which is built into the mount.

Only now are you good to go. When reading those instructions if you found yourself thinking oh just get on with it (as I would have done when first starting out) then this mount might not be for you, you have to do all that every time you want to use it and there's no way around it.

But once you do learn how to set it up it fast becomes second nature and your reward is a smooth and accurate way to track objects through the sky with a simple turning of two special oversized slow motion nobs, Right Ascension nob moves the telescope horizontally and Declination nob moves it vertically.

Now that we've gone through how to set it up we can look at the quality of the mount as well as some pros and cons over other mounts.

The mount is built using thick metal but is not as heavy as you might think, in fact my ply wood dobsonian mount is indeed heavier even when the counter weights of the CG-4 have been installed.

The build quality is excellent, tripod legs are sturdy, RA and dec locking nuts lock tightly and the mount is generally neatly painted. The only problem is the paint scratches off easily along the dovetail bar (where the scope is attached to the mount) but I'm not sure of a way around that. It's not important though as it only affects the aesthetics and doesn't impact at all on functionality. If it does bother you then the occasional reapplication of black paint will easily sort it out.

-Pros-
.Lighter than a big Dob mount
.Provides accurate and easy tracking providing polar alignment has been performed correctly
.Solid and Sturdy
.Adjustable tripod legs means you can adjust the height of the telescope

-Cons-
.Much more expensive than a Dob mount
.More complicated set up
.Takes up more physical space in storage
.Harder to transport


If I was reviewing the mount when I'd first started I would have discouraged anyone from using one, in retrospect this was down to my inexperience and haste. Now I've taken the time to learn how to use it, the CG-4 has become a vital astronomical tool. Especially as I'm just taking my first steps into the world of astrophotography where this kind of mount is at it's most useful. I've already shot a few pictures of some of my favourite craters on the moon which I could never have taken without the smooth and fluid tracking offered by this system, next stop Jupiter....say cheese!

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