Quote:
Originally Posted by -George-
Thanks for feedback.
The limiting magnitude and resolving power is the same on all of them...
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George
Further to your questions.
The limiting magnitude and resolving power is primarily a function of aperture with a bit more limiting magnitude if there is a major difference in coating reflectivity. So 2 12" scopes should show very similar figures here.
As far as the Meade versus GSO/Bintel scopes, yes they all come out of the same factory in Taiwan, so the optics and coatings are identical. I used a GSO 12" solid tube for years and was very happy with it. The big decision to be made is whether you want a truss tube and the price accessory mix.
With collimation tools, a lot of people (especially beginners) get hung up on collimation. Yes it is important to have a scope collimated, no it is not important that it be 100% rather than 99.9%. The amount of work required to get that last little bit is simply a waste of time that is better spent observing, or deciding on your next target or reading posts on IIS! When you get your scope, set it up, collimate it as best you can observe a couple of targets then turn one of the collimation knobs 1/2 a turn. Then have another look. If you can tell the difference ( and here I am talking about a 12" f5 GSO type dob or similar) you have better eyes than nearly everyone on the planet. I have done just this and the experiment helped me to be far more relaxed about collimation. By all means get good quality tools and take your time but stressing over 0.1% is just not worth it.
A good guide to Newtonian collimation is here
http://www.astro-baby.com/collimatio...on%20guide.htm
With charts, I used these
http://www.bintel.com.au/Accessories...oductview.aspx for a long time before upgrading to Uranometria and found them excellent if used along with a planisphere.
A Telrad is a good idea, or a simple red dot finder. Helps you to point your scope at a bright star to commence a star hop.
OIII filters are best used on planetary nebs, a good one is very useful but I wouldn't consider it essential to start.
Eyepieces. Usually my recommendaton is to use the EPS that coem with the scope first. It is possible to spend a LOT of $$$ on eyepieces so you want to make the right choice. Usually the GSO/Bintel scopes come with a range of EPs with a 25mm plossl a wide field about 30-32mm and some shorter one. You will find yourself using the 25 most and they are usually not a bad EP (especially considering it is essentially free with the scope!). Once you know where your observing interests lie, you will be in a better position to spend your $$$ wisely.
Cheers
Malcolm