Search found 13 matches

by hhzhang
Sun May 24, 2020 2:00 pm
Forum: Astronomy Events & Observation Sessions
Topic: Dark sites on the island
Replies: 0
Views: 21

Dark sites on the island

Visit https://www.lightpollutionmap.info and feel.... There are two sites that might be relatively darker. 1. Near the Changi Exhibition Center. There is a huge parking space n open field. Go further towards the shore and away from the road. The North sky is quite dark. Unfortunately it is closed. I...
by hhzhang
Sat May 23, 2020 6:07 pm
Forum: Beginners Forums
Topic: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions
Replies: 11
Views: 130

Re: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions

Airconvent wrote:
Sat May 23, 2020 4:51 pm
Thanks for sharing hhzhang ... that is indeed detailed! Stay safe :)
Welcome!

Hope everyone here will begin to realise the fact we do have certain advantages over those in other regions when it comes to polar alignment.

Clear skies!
by hhzhang
Sat May 23, 2020 9:32 am
Forum: Beginners Forums
Topic: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions
Replies: 11
Views: 130

Re: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions

Job done.

Wish for clear night skies.

Sadly the wet weather persists and I seem to miss the galaxies season totally.

Not a fan of nebulosity, what shall be my targets for the summer?
by hhzhang
Sat May 23, 2020 9:29 am
Forum: Beginners Forums
Topic: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions
Replies: 11
Views: 130

Re: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions

# Don't know how to attach a file. So here goes the py script. # !!! The forum automatically removes the indent spaces for the code lines :(( Be aware. You need to add those spaces back for the script to run properly. # -*- coding: utf-8 -*- # Image blinking for quick alignment of scope view with a ...
by hhzhang
Sat May 23, 2020 9:25 am
Forum: Beginners Forums
Topic: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions
Replies: 11
Views: 130

Re: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions

I probably spent too much time on the writing here. Just wished it could be of help to some of the other equatorial-region users of EQ mounts. But with all the above posts, it has become straightforward to implement the techniques in the PA practices. So it is time to just quickly revisit the steps ...
by hhzhang
Sat May 23, 2020 8:57 am
Forum: Beginners Forums
Topic: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions
Replies: 11
Views: 130

Re: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions

Before moving on to quick and easy GOTO-based alignment, let's examine the theory and assumptions. This is clear: your GOTO will be absolutely accurate provided all the three things are absolutely accurate at the same time A. Your leveled RA zero position B. The GOTO function C. Your PA alignment Th...
by hhzhang
Fri May 22, 2020 12:13 pm
Forum: Beginners Forums
Topic: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions
Replies: 11
Views: 130

Re: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions

We need to stay reasonable when expecting precision target. Is 1-arcsec precision a reasonable target? I doubt it. 1-arcsec is a mere ~4.5mm lateral distance across the view at a distance of 1KM. Would your scope be able to stay spot on such a small visual/image feature? Considering there are atmosp...
by hhzhang
Fri May 22, 2020 11:29 am
Forum: Beginners Forums
Topic: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions
Replies: 11
Views: 130

Re: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions

Now let's get started with determining the mount RA axis in the polar scope. Get ready some handy tools: a tubular spirit level (mine is a cheap $3 one and when combined with my mediocre vision, produces >2.4arcmin sensitivity to tilt), and of course a computer. Before you move on, make sure the scr...
by hhzhang
Fri May 22, 2020 10:21 am
Forum: Beginners Forums
Topic: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions
Replies: 11
Views: 130

Re: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions

Precision is all about fighting errors here and there. So here is a quick check on some of the errors I can measure/estimate on my system. The polar scope. I have measured the pixel size and determined that each pixel is about ~32.73". Roughly half of arcmin. This seems quite good (using advanced te...
by hhzhang
Fri May 22, 2020 9:57 am
Forum: Beginners Forums
Topic: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions
Replies: 11
Views: 130

Re: Towards Quick and Easy Polar Alignment for Equatorial-Mount Users in Equatorial-Regions

As mentioned earlier, the idea is as simple as aligning the EQ mount with reference to terrestrial objects instead of a celestial one. This logically leads to the questions: How do we determine (measure) where my EQ mount is pointing? How do we determine (measure) where the celestial pole is with re...