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Old 21-11-2018, 02:51 PM
Placesinthedark (Stephen)
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Placesinthedark is offline
 
Join Date: Nov 2018
Location: Stanthorpe, australia
Posts: 17
Quote:
Originally Posted by mental4astro View Post
Hi Steve,

to IIS!

A 10" dob is a BIG scope. A 12" scope is and even BIGGER scope. A solid tube 12" dob will be a challenge to fit into most cars, such as a sedan or small hatchback. A 10" while a little easier to handle loses a lot in terms of aperture compared to a 12". I have owned a solid tube 12" scope, but it wasn't an issue for me to transport because I have an SUV. Like Patrick said, a 12" solid tube scope is a BIG unit A 12" solid tube scope may fit down the whole length of the passenger side of a Kia Rio.

If you have the space at home, and car, I honestly would suggest going for a 12". This aperture size begins to allow you to resolve the arms of the larger spiral galaxies. A 10" won't. And that's what it comes to in astronomy - the bigger the aperture the better.

In so far as dealing with Andrews Communications, I can recommend them 100%. Give them a call and ask if they could give you some idea on the dimensions of a solid tube 10" and 12" scope. Or someone here could. Either way, Andrews Com are very approachable and knowledgeable.

Cheshire or laser? I say BOTH! A Cheshire will actually allow you to do the whole collimation process, secondary mirror and primary. A laser is ONLY for the primary mirror, it will not sort out the secondary mirror. In the collimation process for Newtonians, the secondary mirror NEEDS to be dealt with FIRST to make sure that it is centered and square with the focuser and then in relation to the primary, and only after the secondary has been sorted do you look at tweaking the primary mirror.

This is something that is not mentioned anywhere enough. Retailers cannot be expected to know your proficiency at collimation, so if you just purchase a laser that's all they care about. And many retailer themselves do not know how to collimate a Newt, so they would not even be clued up enough to ask if you do.

I started out with a cheshire eyepiece, but sold it to get a laser. No one told me about the above collimation process, and I too mistakenly thought a laser would do it all. And it took me six months of frustration to work out something was not going right, and then I looked at the secondary mirror through the draw tube and saw that it was WAY off. It was then that I worked out that the laser was not the fix-all took I thought it was. I then got another cheshire, use it with the laser, and never looked back.

Alex.
Thanks for the info, I think Cheshire will be the way to go honestly.


By the sounds a 12" will ensure my girlfriend won't fit in the Rio with the dob. Since she has the purse strings I'll have to consider a 10" and think about moving up to a 14" in the years to come.
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