Quote:
Originally Posted by robz
Thanks for your input guys and gals! 
I'll check out the thread links and will probably go and build or buy a large Newtonian for my EQ6PRO mount  |
A Newtonian with a first class mirror is hard to beat on planets if the secondary is kept small, say under 20% obstruction by diameter. To ensure you do get a first class mirror I would recommend you have one made to your specifications than going with a mass produced mirror. It will cost a lot more and it will come down to how good an image you want and how much you want to pay for it. Note a first class mirror will perform on all objects not just planets. Stars will be tighter and fainter fuzzies will be seen.
A large Newtonian will take longer to cool but once stabilised it will out perform any smaller refractor for detail. However, for quick but quality views a small 4" APO is hard to beat. You will see all what the refractor is cabable of showing within minutes of setting up provided the seeing is good of course and this view often rivals larger 'scopes since those 'scopes are still stabilising or optics are mediocre.
Note too a large Newtonian on an equatorial mount really needs a set of rotating rings to ease access to the eyepieces and avoid difficult viewing angles.