Polarie Vs AstroTrac: Compare & Review

[iceman (Mike)]

Excellent review Roger.

I think like Greg has said though, saying costs are equal is probably not fair on the Polarie. I don't know anyone else who has bought a $500+ geared head to use for the Polarie.

I use 2 484RC2 ball heads (one under the Polarie, one for the camera on the Polarie).

I would recommend also, looking at the Polar Meter for the Polarie - a far easier and quicker method to align (it sits on the hot shoe) and doesn't require the ghastly polar scope. And it's only $60.

[rogerg (Roger)]

Originally Posted by iceman

I think like Greg has said though, saying costs are equal is probably not fair on the Polarie.

I agree the Polarie can be mounted on much cheaper - I for one mount it on a cheaper head as evident in the photo's. I've updated my review to reflect this.

The problem comes in trying to draw a direct comparison for the purpose of the rest of the review, and I don't think a ball-head is comparable to the AT wedge, they are in a different league in terms of ease of slight adjustments and holding rigidity.

But, I definitely agree you can get up and started cheaper with the Polarie if you are not looking for the same attributes as the wedge, so hence the review update.

[Peter Ward]

Thanks for the review Roger ...but I'm still wanting...

When it came to mounts I tried to get a de-facto test standard happening with a few equipment reviews I wrote for Sky & Space magazine (many, many moons ago) , via some simple and reproducible quantitative measures.

First up: periodic error? With an CCD and small telescope this error is easy to measure.

Rigidity?: how much does it flex? I used to hang a 1kg mass on a focuser,
(with video camera providing a feed of a star) and measure the deflection, in both unloaded and loaded states.

Quickly lifting the 1kg mass I'd time the period (looking at the video feed) it took for vibrations to dampen.

Mount weight, set-up time through to GoTo pointing accuracy (if applicable) can also be measured.

My hope is: if all reviewers did the same, we could compare apples with apples

[rogerg (Roger)]

Originally Posted by Peter Ward

Thanks for the review Roger ...but I'm still wanting...

When it came to mounts I tried to get a de-facto test standard happening with a few equipment reviews I wrote for Sky & Space magazine (many, many moons ago) , via some simple and reproducible quantitative measures.

Yes, I thought through all those quantitative measures and then decided I didn't have time to do any of that so may as well just write what I knew

Originally Posted by Peter Ward

First up: periodic error? With an CCD and small telescope this error is easy to measure.

I wanted to measure this on the Polarie and AT because in theory the AT has very low PE intrinsic in it's design, where as the Polarie is a standard worm so I would expect has standard error. Then I thought - what does it really matter? People who are using a Polarie are doing 2 min exposurs max and aligning it using relatively crude means. I wonder if any PE difference is immaterial under the circumstances Either way, would be interesting to measure given time and dedication to the cause

Originally Posted by Peter Ward

Mount weight, set-up time through to GoTo pointing accuracy (if applicable) can also be measured.

These kinds of mounts set up so quickly I think the only material difference is in polar alignment ease, which is covered (although accessories can enhance this as pointed out by people..) Most of the time is in choosing the composition or hiking to the desired site It would be nice if I summarised setup time as an extra criteria.

Originally Posted by Peter Ward

My hope is: if all reviewers did the same, we could compare apples with apples

I hope others do too