How to align a Vxen Polarie

[gregbradley]

I have a Vixen Polarie and its a great little unit. It struggles outside its wieght limit (I am using a Nikon D800E with a grip, a heavier battery and a Samyang 24mm F1.4 or Nikon 14-24mm F2.8 lens - both are heavy).

I have the polar alignment scope and I have only tried to use it twice in a location that had trees blocking a clear view of the South.

So I found a quick way to align it based on CCD drift aligning.

Firstly level the tripod so you know you are horizontal. You can use a simple bubble level to do this.

Now set the Polarie to the correct latitude for your location. This seems to be pretty easy with the nice illuminated angle indicator on the side of the Polarie. I also got a cheap digital inclinometer off ebay to check this.
I think you can get it pretty close quite easily and not worry about it further.

Now set the Polarie halfway between Hadar (the closer of the pointers to the southern cross) and Achenar. Use the compass to get it close to start with and adjust it further this way. If these stars are not visible then the LMC SMC and Alpha Centauri form a rough triangle with the SCP.

Using around a 24mm lens take a 30 second exposure. Examine the image. If it show bad star trailing then swing the Polarie one way or the other. Take another. Examine. Is it better or worse. If its better you moved the right way. If its worse you moved it the wrong way. Now you are getting a preliminary feel for how far off you are. Repoint the Polarie east or west on a best guess spot. Take another. Examine. You can get round stars within 3 or 4 goes of this. If you turn off long exposure noise reduction you are only waiting 30 seconds to find out how close you are. So its kind of fast.

I was able to adjust it to quite round stars within 5 minutes or so.

The accessory that slips on the hotshoe would be helpful and speed this process up.

I hope this helps.

Greg.

[lacad01 (Adam)]

Thanks for the handy info Greg, will have to try that next opportunity. As my eyes for close-up are pretty crap, I can't read that lattitude marker on the side, even with reading glasses on so I use a couple of iPhone apps for levelling, lattitude and south setting which works a treat.

[dannat (Daniel)]

thanks

[seeker372011 (Narayan)]

Originally Posted by gregbradley

The accessory that slips on the hotshoe would be helpful and speed this process up.

I hope this helps.

Greg.

What accessory is this Greg?


I too have been using a similar method for the polarie and it seems to work fine.

As a tweak I use a zoom lens at a much longer focal length than I plan to image for the polar alignment routine and take ever longer images.ie start at 30 secs and go up to 2 minutes, and keep adjusting to get round stars..till I run out patience

Also use an android tablet to control the DSLR so am laptop free.

Image at a bit less say 90 seconds.

[gregbradley]

Its an inclinometer and compass and it fits onto the hotshoe of the Polarie. My Astro Shop sells them. They are about $67.

Greg.

[gregbradley]

Originally Posted by lacad01

Thanks for the handy info Greg, will have to try that next opportunity. As my eyes for close-up are pretty crap, I can't read that lattitude marker on the side, even with reading glasses on so I use a couple of iPhone apps for levelling, lattitude and south setting which works a treat.

I use a bright torch to lit it up as I too would find it hard in the dark to be precise.

Greg.

[OzEclipse (Joe Cali)]

Originally Posted by lacad01

Thanks for the handy info Greg, will have to try that next opportunity. As my eyes for close-up are pretty crap, I can't read that lattitude marker on the side, even with reading glasses on so I use a couple of iPhone apps for levelling, lattitude and south setting which works a treat.

http://support.apple.com/kb/TS2767
The built-in digital compass works just like a magnetic-needle compass. The accuracy of digital compass headings can be affected by magnetic or other environmental interference, including interference caused by proximity to the magnets contained in the iPhone earbuds. The compass may need to be calibrated from time to time.
When the device displays the calibration alert, rotate the device in a figure 8 motion until the calibration screen disappears. The digital compass should only be used for basic navigation assistance and should not be solely relied upon to determine precise locations, proximity, distance, or direction.


The Polarie has motors therefore it has magnets. Same goes for the device that fits in the finder and the little ball compass located inside.


I have a 0.1 degree inclinometer, sounds similar to Greg's that I also got from an ebay store for $26.

There must be a better way to do the compass setting.


Joe

[Steffen]

Yes, the iPhone compass is just as unreliable as any other magnetic compass.

The accelerometer on the other hand is very good. The Clinometer app for example ($2) gives very accurate and repeatable readings with 0.1 degree resolution and doubles as bubble level. Combined with the shape and rigidity of the iPhone 4 and later this makes for a very handy tool.

Cheers
Steffen.

[jjjnettie (Jeanette)]

I'd still like to adapt a finder scope to fit in the big central hole so I can do a proper drift align.
I usually have a lappy with me anyway when I go out on safari with the Polarie. I can plug it into the inverter if need be.