Comparison of Rough Polar Alignment Methods

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tradesmith45 Senior Member • Posts: 2,129
Comparison of Rough Polar Alignment Methods

Have a couple small trackers - Sightron Nano Tracker & Vixen Polarie. Over the years have used different approaches to polar align these for starry landscapes using EQFL of 16 to 85mm & 135mm a couple times. Lacking confidence, I usually stick w/ 30" max exposure.

Like many of you, I wanted to polar align w/o craining my neck from below. Haven't seen tests of the numerous recommendations for each of these methods. Decided it was far past time to see which of these methods worked best:

  • Eyeballing Polaris and placing tripod/tracker pointing "correctly".
  • Compass & Inclinometer
  • Cell phone compass & inclinometer
  • Vixen Polariemeter compass & inclinometer
  • Cell phone planetarium app & center Polaris behind tracker
  • PS Align Pro app
  • Laser pointer mounted on tracker
  • Peep hole on tracker

I tested each of these by aligning the tracker then taking 8 consecutive 15" star images facing East using EQFL of 85mm (Fuji XF56mm). I stacked images sequentially in PS until trailing started. This gave me the longest usable exposure for each method.

Short version of the results are eye balling Polaris was as accurate as the first 6 of these & can gave 30" w/o trailing. The simply mounted laser pointer barely gave 45" w/o trailing.

Peep holes rock. Could get 1 to 2 minutes w/o trailing. The reasons most of these are inaccurate are simple.

Here's my old standard compass & inclinometer, Vixen Poalriemeter & DIY laser pointer mount.

All the approaches that use a compass are impacted by magnetic deflection from the tracker. I had hopped the Poalriemeter would be less sensitive because it set above the tracker but if you look closely below, it to is deflected 5-10º,

All the cell phone apps that use the compass are also deflected & inaccurate. Inclinometers - cell or physical - are accurate.

Because they do not point parallel to their axis, the laser pointer is inaccurate w/o an adjustable mount that can be sighted in. But that means you'll need a polar scope for tracker alignment for sighting in the laser:-D

Of course at shorter FL, all these alignment methods work reasonably well. But you can probably eyeball the alignment & use you phone angle meter to do as well as anything except for peep holes.

Hope this is helpful.

One last thing. Do have a polar scope for the Vixen. Bought an angle finder & adapter for it. Works ok but the high eye point of the angle finder doesn't show the whole FOV of the polar scope, reducing it by perhaps 1/3rd. That means as landscpaer1 found unless the tracker is already close to aligned, you'll have a hard time finding Polaris in the angle finder view.

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Fujifilm X-T2 Olympus E-M1 II Fujifilm X-T20 Fujifilm X-T100 Fujifilm X-T3 +13 more
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