New NEQ6 - Polar Question

[glend (Glen)]

My NEQ6 Pro has arrived, and what a beast it is. I can see this will never be a grab and go mount!

After expereince with Pushto Dobs, Alt-Az pushto Vixen Porta II, and Goto mounts like the iOptron Smartstar, I am finding the EQ6 a bit daunting, and its not just the weight.

My question is should I worry about polar alignment when using it for visual use? Obviously the Octan stars, which are mentioned in the Mount Manual (not very well done I think), can be used but only when it is really dark at my place and I'd rather setup while it is still light or twilight if possible.

Can I just keep doing what I did with the iOptron, which is to level the mount, use my good compass and laser desgnator to show true South (or SCP azimuth), set the mount latitude (33S in my case), and then do a star alignment from there?

Finally, when I am ready to try some imaging, can I still use this technique or do I need to use the polar reticle technique in the manual? I realise Drift Alignment is also possible. I guess I am saying is polar alignment a necessity in the Southern Hemisphere?
Thanks

[Steffen]

The polar scope offers no precision, is difficult to use without
Polaris and generally ignored among Southern Hemisphere observers.

Level the scope (I do it by eye) and point it roughly south. An initial 2-star alignment will show how far off the polar axis you are. In fact, the slew to the first alignment star will show how well you guessed the south direction. Correct the error by moving the mount, run another 2-star alignment and you'll likely be within a degree or two. The SynScan polar alignment routine will then let you zero in on precise polar alignment.

For long-exposure imaging you may follow up with camera-based drift alignment, which is fast and accurate.

Cheers
Steffen.

[Astro_Bot]

Actually, I use the polar scope most sessions, from my suburban yard with street lights on the corners. It's not hard, but if transparency is poor, it can become a bit frustrating, though that's surprisingly rare.

When I was using v3.35 firmware, the Mel/Maz readouts were always within 10 arcminutes, often 2 or 3, which was about the same as the results I got using SynScan's polar alignment feature. Keep in mind, though, that what SynScan calculates as your error and the real polar alignment error may be two different things.

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Do you need to polar align for visual? No, not really. The more accurate the polar alignment, the less drift over time at the eyepiece, as well as better GoTo slews, though the latter also depends on your 2/3-star alignment accuracy and the geometry of stars you used in that process.

Once you get to imaging, you'll probably want to not rely on the polar scope as it's accuracy can be limited, depending on how much time you spend on it - it's OK for short-medium exposure astrophotography. Since I have a personal dislike of the SynScan polar alignment routine and find its accuracy no better than the polar scope (and some people find it buggy whilst others don't), I suggest using something like Alignmaster from a laptop. Drift alignment is accurate, but I disagree that it's fast ... anyway, you can use a laptop and camera to make drift alignment more comfortable and more reliable, if not actually faster.

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To align with the polar scope ...

First, set up the tripod with compass - you only need to be within 3 degrees. Level the tripod (I suggest getting a digital inclinometer - about $35 off eBay) and, when the mount is on the tripod, adjust the elevation to your latitude (using said digital inclinometer, as the latitude scale on the side will probably be out by a few degrees).

In the polar scope, you should find that Octans is roughly level with its corresponding reticle pattern and to the left or right within 3 degrees (your compass alignment accuracy), which means it is always in the field of view (tip: the image is inverted). If you've oriented the Octans reticle pattern correctly*, then Octans should be easy to spot.

Make further Alt/Az adjustments as required.

* I wrote a procedure to make using the polar scope easier. Most of it is something you only need to do once. See post #19 in this thread.

[glend (Glen)]

Thanks guys, I have an inclinometer so that's no problem. I will read the link and take it from there. Very clear. Thanks

[killswitch (Edison)]

I found the polarscope difficult to use even at a dark site. If i set the Polarscope LED brightness to 2% the faint stars get washed out and if i turn off the LED the asterism guide disappears. Go figure..

I do what Steffan does, do a 2 star alignment and adjust the mount to get close to the first alignment star. I then use the Synscan Polar Align feature to fine tune the mount even more.

For imaging it has to be drift alignment. Look up the DARV method at Cloudynights

[Astro_Bot]

Odd. I use the polarscope LED set to 2-4% most of the time from my suburban site - and I'm sure that's brighter than your dark site. I start with 10% to see the whole reticle and orient myself to how Octans should look, then 0% to spot Octans (which usually takes less than a minute) then 2-4% during adjustment.

It's hardest when the moon is full. Combine that with below average transparency and those are the nights when the polarscope just doesn't do it.