Re: Anyone using RAPAS in Southern Hemisphere? Mach1 payload rating?


Hi Henry,

In the southern skies we usually drift align on a star close to the meridian on the celestial equator, such as Sirius, or any other one. It's dead easy, polar alignment here is not. PemPro has a really great polar alignment section, you can get pretty close to perfection in not an unreasonable period of time. Another way once described on this forum involves a two minute trailed star image in one direction, then back again. The 'wedge' pattern needs to be corrected in the usual way (altitude/azimuth) until it's minimized into a straight line. Once again - easy. My permanent setup is within 10 arc seconds of the pole in both axes, and if I wanted to spend more time at it could get it closer, but it shouldn't be necessary.


From: ap-gto@... on behalf of Suresh Mohan Neelmegh drsureshmohan@... [ap-gto] <ap-gto@...>
Sent: Friday, 6 January 2017 11:04 p.m.
To: ap-gto@...
Subject: Re: [ap-gto] Anyone using RAPAS in Southern Hemisphere? Mach1 payload rating?

Hi Henry,
 i wont be able to say about southern hemisphere but about payload, i use the astrotech 12 inch newtonian and works like a breeze. The weight  is 30 kgs (however the place i live is not windy at all). Next coming to your polar scope it will depnd on you r latitude,i live at 13 deg N and Polaris keeps dancing ,so i wlll need to tune with pempro or PHD2 for fine tuning which takes ten minutes.

On Sat, Jan 7, 2017 at 9:20 AM, [ap-gto] <ap-gto@...> wrote:


I polar align at the moment using a Polemaster, which works fine but it is still a hassle with computer etc. I heard many praises of the RAPAS but not sure how well it works in the Southern hemisphere. The southern pole star sigma oct is so dim that at the moment using the Polemaster I have to resort to plate solving on astrometry what I can see on the screen to know where the pole star is if at all in the FOV, What has your experience been?

Also with Mach1GTO's payload rating of 20 kg - does it need to be derated for astrophotography? I am contemplating venturing into imaging newts but they are a lot heavier than refractor / RC / SCT for the same focal length. What is the max aperture imaging newt you have successfully used with the Mach1gto? I am thinking either a 10" f/4 steel tube Astrotech newt or a home made truss newt to say 12.5" -- too ambitious?


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