Star Adventurer - Southern Hemisphere - Quick Polar Alignment
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- เผยแพร่เมื่อ 5 ต.ค. 2024
- With the aid of a simple home-made tiltmeter you can achieve reasonably accurate polar alignment even in daylight. But this process vastly simplifies finding Sigma Octans in the polar scope and makes accurate polar alignment very quick and simple once Sigma Octans becomes visible in the evening sky.
Since posting this video I have found some great smartphone apps that can make this daytime "alignment" much easier and more accurate.
1. There are plenty of Compass Apps available. Just download one that gives you the option to select True North or True South, rather than Magnetic. To avoid any magnetic interference from the StarAdventurer, I just stand a metre or two behind the mount, set the app to True South, and rotate the mount left or right until it is pointing towards true South.
2. There are plenty of Inclinometer Apps that that can help achieve a more accurate tilt of the StarAdventurer polar axis to match your local latitude. A simple, and excellent app, is the Velux Roof Pitch app (but there are plenty of other apps too). Load and open the app on your phone. Place the phone edge along the altitude wedge and adjust the tilt angle until the app reads your local latitude angle.
The Sigma Octans group should now be visible (or very nearby) in the StarAdventurer polar scope once the sky darkens.
This is the best, precise and useful tutorial on the net. Excellent !!!
So good to just honour the basic skills and the good old common sense!
I live in the NH and this is still useful. Thanks!
THANKYOU...
Very very helpful
Many thanks
So smart! Excellent idea, it can be used for NH as well!
Great ideas.Sometimes old school full analogue solutions work best.I have compass and clinometer on my (smart?) phone but if I put it near metal or electronic devices the readings get messed up,making it useless.This is the perfect solution.
great Vid . Makes it so easy to use.
Right, I'm off to find the bits to make a tilt meter just the way you suggested. I spent ages last night chasing that dammed elusive Octantis. And I missed quite a bit of the Tour de France! The sky was beautiful though in Southern Tasmania. Thanks for the excellent video.
An even better option is to search your app store for the Velux app. It's is a voltmeter used by roofers. It works very well.
Stupid autocorrect. It's is a tiltmeter. Velux roof pitch measure
I used a very similar process to align my Sky Adventurer, and found that the screw lines on my patio floor run true east-west, so placing two tripod feet on the screw line leaves the third tripod leg aligned true south towards the south celestial pole. It makes my alignment very quick and easy. I will try the Velux slant app for the wedge angle next as the scale is quite small and difficult to measure to less than 1 degree of elevation.
Imcidentally I found one of my compasses is faulty, possibly due to being balanced for the Northern Hemisphere so the needle drags against the inside of the housing and doesnt settle on Magnetic North - its also very heavily damped so slow to react to changes in position, and often doesnt react at all.
My other compasses (1 x Silva hiking campass 7NL model and 1xALDI special ) are correct.
Very helpful information thanks !!
Thanks for this handy tip :)
Thanks for a very good video
This process requires star visibility when pointing South, right?
Let say there is an object blocking the polar alignment visibility ie mountain, Building etc.
How much accuracy? For example , Wide angle lens with 2 mins exposure ,,Is this possible?
Thanks
I had forgotten to allow for the 19 degree magnetic dec. thanks!
Timely video for me. What tripod are you using. I plan to use the Star Adventurer in Botswana next May.
It's just the standard tripod that comes with the Adventurer.
Great method of daylight polar alignment. Just not quite clear on the protractor reading. (silly me.) I note that your latitude is 27.5 degrees. Though the indicator needle is positioned about 61 degrees (reading the inner scale) at 3:56. Unless I'm interpreting this wrong?
Hi Anzaeria. You are right, my latitude is 27.5 degrees. So, the South Celestial Pole is 27.5 degrees above the southern horizon at my location. At around the 1:36 point of the video you will see the verticle needle is roughly 27.5 degrees from the 90 degree mark of the protractor. Just ignore the actual numerals on the protractor. What you need to achieve is a tilt of the StarAdventurer polar axis above the horizon that matches you local latitude. You will see some red arrows and text on the video at about this point that indcates the required 27.5 degrees above horizontal tilt for my locaton.
Actually, since I created this video there are now some better Apps available for download to smartphones. There is an excellent inclinometer app called Velux Roof Pitch that is really good for adjuusting the altitude angle of the StarAdventurer to match you local latitude. Also, there are plenty of smartphone Compass Apps that have a True North option (and not the Magnetic North option). Just select True North or South and use that to aim the StarAdventurer to the true south of the celestial pole. Using these two Apps you can get Sigma Octans into the polar scope field of view very easily.
@@peterallison57 Thank you for the detailed reply. That makes perfect sense. Apparently, the latitude of my location is 35.7 on Kangaroo Island, South Australia. There are some very clear, dark skies over here with very minimal light pollution. Actually 0 light pollution in some spots. Though I admit I don't have a star tracker as yet (Ive been doing astro shooting from a fixed tripod.) Out of curiosity, does the Velux Roof Pitch app have a virtual needle?
Great video. I just got my hands on a Star Watcher Adventurer and am dreading setting it up for the first time, as it didn't come with the illuminated finder, (it has the scope though). I haven't used as yet as we have been shrouded in cloud the lasst few nights. My questions are:
1: How accurate does the polar alignment need to be for astrophotography, ( Olympus OMD M5 ii with various lenses), and variour shutter speed of 1 to 4ish minutes?
2. Can I get away with using the method show in your video, and not worry using the finder scope, or does the alignment need to be perfect?
Thanks, again, great videos.
The wider the lens field of view, the more forgiving it is to inaccurate polar alignment. It's not really possible to give you a clear answer to your questions as you will never really know how far you are from perfect polar alignment unless you use the polar scope and actually see the extent of misalignment. In the southern hemisphere I use the quick alignment process first before it gets dark and that usually gives me a polar scope visual on the Sigma Octans group of stars as soon as the sky darkest. It saves me time and frustration. But I always finish my setup using the polar scope and get a good polar alignment. I once did a 12minute single exposure ( because I got distracted and forgot the camera) with a 16mm lens, and the star were perfectly round. But try with your widest lens first and see what results.
@@brisbaneastronomicalsociet9252 thanks. Just waiting for a cloudless night down here in Melbourne.
@@bradwarrior1000 good luck...let us know how it goes. I'm a step behind you
Nice vid but too much limbo action needed. Sharpcap Pro ftw.
I live on the north western outskirts of Canberra and if there is any light in the sky from the moon, it is almost impossible to see Sigma Octantis. The light pollution from Canberra itself is mostly below the south celestial pole. No matter how perfect I set my Star Adventurer up, I can't see those four little stars especially the two towards the outer rim of the eye piece. I am leaning towards some other method of finding the pole as I can't use the Star Adventurer (SA) for most of the month. I can get light pollution filters for my imaging device but I am lost with those four pathetic little stars. Do you know of some more accurate way to find the pole without relying on the polar alignment eyepiece with the SA? Thanks.