Aligning your polar scope, have you done it?

[ombos]

Hi All

I'm no expert at this game and never will be but I'm happy if I can to help someone with my limited knowledge and from my past mistakes. Heres one of my mistakes, I just didn't see the need for it. But I can tell you that it wil improve the tracking of your mount many folds.

Set your mount up as per usual and WITHOUT your scope on align Polaris just under the 'Cross hairs' of your polar scope by adjusting the Altitude and Azimuth of your mount. Now slacken the RA locking device off and slowly turn/rotate 180 degrees (try looking at the same time though your polar scope NOT EASY watch you don't damage your eye) if Polaris is still in the same place then your Polar scope is aligned, but 99 times out 100 it won't be! so in fact your not really polar aligned are you??

Now slacken off and tighten your Polar scope adjusting screws by very small amounts until Polaris is half way back to the center of the reticule. Now recenter Polaris to the bottom of your cross hairs via the Azimuth and Altitude adjusters on your mount. Rotate back 180 degrees and check again. Keep doing this slowly and gently so you don't damage your polar scope and you will see just how far your original setting were out by. I'm learning that this is the minimum Polar alignment but at this point I can't be bothered with downloading Polaris positions and adjusting accordingly.

Hope this helps someone, it made a big difference to my tracking.

[Dangerous-Dave]

Nice one. I did mine during daylight using landmarks across the valley from us as fiddling about with allen keys in the dark is a bit of a bind.

[Macavity]

Thanks! I must admit, I did vaguely try... Particularly the guide book method re. aligning the polar scope coaxially with the mount axis? But, back then, it seemed to be an INDOOR (and time consuming!) project only and, with weights (variously) removed or in place, I mostly remember it was notable for pinching FINGER (flesh) rather severely!

I sense there is (as you suggest?) not much point in going MUCH further than this (re. the offset of Polaris wrt the true Pole) at least by this method. Perhaps not within the systematic "re-setability" of the mount anyway? The (small!) RANDOM errors (of even e.g. the humble EQ3-2) are impressive tho', seeming to merit e.g. drift alignement etc.

[jgs001]

I did this, but like Dave, during the day. I've been able to get between 3 and 4 minutes accurate tracking without trails on imaging just with using the polar scope to PA. I followed Astro_baby's tutorial on setting up the HEQ5. I also set the time and date scales according to the instructions, so now only have to turn the axis to the current date and time, and the PA is pretty much spot on. I suspect it'll be close for the other mounts though.

[Jeremy]

I can't be bothered with downloading Polaris positions and adjusting accordingly.

It's a common misconception that you need to download software or look up Polaris transit times on the internet. You don't!

That's what the polarscope is designed to calculate!

Provided that your index ring is correctly calibrated (which only needs doing once), and the index ring is either zeroed against the date wheel or (if significant) set to the relevant E-W offset, then all you do (on HEQ5 for example) is:

1) Lock the time wheel (zero hours at top)

2) Rotate the R.A. axis so today's date lines up with the current time

3) Fit Polaris into the little circle in the reticule

- and you're done!

I don't know where this nonsense about looking up Polaris transit times on the internet came from.

[jgs001]

I did it the once to align the date/time rings on the HEQ5... now as you say, rotate the axis so the date and time lines up and away we go.

[NickH]

used a combination of a freeware app and drift alignment on mine..bang on the money on the pier now...

Credit where it's due, the all star polar align routine on the CGEM is pretty tasty!

[Helen]

Nick,

Has EQMOD got a version of the all-star polar align?

Helen

[NickH]

Helen

No, sorry ...I meant on the CGEM mount itself.

EQMod would be a nice update (and pretty easy in software) to implement that routine

[Helen]

Thanks Nick.

[Jeremy]

Has EQMOD got a version of the all-star polar align?

I don't know if it's of interest, but I was doing EQMOD "n-star" alignment the other day (with one of those new EQDIR cables from Steve at FLO) and was stunned at the resulting accuracy after just 3 stars.

All my targets ended up in the centre of the scope view (not merely the finder) - and that was at 85x magnification.

I was quite blown away by the experience.

[Helen]

Yes, that feature does look good! and the explanation behind it was fascinating too!

I haven't managed any sky time to do an alignment of my mount yet though

Helen

[NickH]

Wait till you get a really big set of stars, it's like having a Losmandy on steroids...the accuracy (even given the shonky conditions we're having) is something else.. (EQMOD via handbox using CDC)