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Breakintheclouds

How to polar align with HEQ5 and EQ6 mounts, and SynScan 3.11+

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malc-c    567

Sorry - RJ11 (I always get those mixed up !)

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malc-c    567

Thanks... - will give that a go.

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DrRobin    3,327

Hi Breakintheclouds,

Simply superb, well spotted. I made the move to EQ in December and have found that setting the polariscope and aligning on Polaris the most difficult task of all of the set up.

I have tried several methods, the one outlined in the manual and by Astro Baby, one based on observation and one based on a Planisphere.

The method based on the manual is too fussy,

The one by observation too inaccurate,

The one using the Planisphere gets to the same place as your method, but takes 3 times as long.

Edited by DrRobin

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philr    10

With reference to the article by Breakintheclouds, there are a couple of extras that need to be explained for successful alignment.

Firstly: ensure that the polarscope is precisely aligned, so that a distant taget remains in the centre of the big circle as the RA axis is rotated. Its fiddly but worth doing properly. Don't over-tighten the three grub screws.

On the Syscan display it is absolutely correct to set the hour angle on the RA axis, the example given was 7hrs 37 minutes; set this as accurately as possible. Adjust the mount to centre Polaris in the small circle. What this does is to correctly reference the RA axis to the celestial pole, meaning that the scope RA axis rotates precisely around it, on the assumption that the scope is well balanced on the mount.

When setting the hour angle, I think I'm correct in saying that the 1 hour forward for BST is corrected for by selecting Daylight Saving when continuing with the Synscan setup.

Once Polaris is aligned it is essential to return the RA axis to the Park position, i.e. zero on the two RA scales, when the mount is squared up vertically - the scope dovetail will be at the highest point, perpendicular to the mount base.

Now go through the Syscan setup and use three star align for the best alignment. If you have done all of the above, the target alignment star should be very close to the scope centre.

Finally; easy setup does assume overall optical alignment. I have done this in daylight by finding a distant object on the landsape, the further away the better. Set you mount up so that the polarscope is centred on that object, check its alignment by rotating the RA axis as detailed above, When you are satisfied with precise centering check to see whether the main scope is centered, you may have to tweak the declination axis. It may also be necessary to shim the dovetail rail to accomodate slight inaccuracies. Once centred, set the Dec ring to zero and lock it firmly. Then tweak the finder scope to centre the object.

Don't forget that leveling your mount is of primary importance.

You may need to consider PEC training and Cone Error set up, especially if you intend to do astro photography.

Get all this right, then you'll find that subsequent set up at different location is as easy as pie.

I think that all this info should be compiled fully if you are happy with the principles.

More clear skys please!

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Ant    3,496

Don't forget that leveling your mount is of primary importance.

Most of what you say I agree completely - great advice, especially the part about aligning the polar scope - I think that catches a LOT of people out.

But an EQ mount doesn't need to be level.

Cheers

Ant

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DrRobin    3,327

Hi,

The only reason I can see for having the mount level is so that the AZ and Alt move in those directions only. If the mount isn't level then moving the Alt setting will also introduce a small movement in AZ, but since this in only to get the polar scope aligned it is of little consequence.

Any error introduced in a mount which is not level is calibrated out when the polar axis is set and the star alignment is performed. Although you probably have to do a 3 star alignment otherwise AZ/Alt errors probably do have an impact.

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dark knight    31

Hmmm shame the hand controller (HC) is required to change the illumination of the polar scope, this means I now have to disconnect from EQMod, and reconnect the hand controller to get the illumination dimmer, then remove HC, reconnect EQMod again. Is the new dimmer setting then "saved"? or does disconnecting the HC reset it to it's brightest again?

I really want to dim mine too.

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philr    10

With reference to the article by Breakintheclouds, there are a couple of extras that need to be explained for successful alignment.

Firstly: ensure that the polarscope is precisely aligned, so that a distant taget remains in the centre of the big circle as the RA axis is rotated. Its fiddly but worth doing properly. Don't over-tighten the three grub screws.

On the Syscan display it is absolutely correct to set the hour angle on the RA axis, the example given was 7hrs 37 minutes; set this as accurately as possible. Adjust the mount to centre Polaris in the small circle. What this does is to correctly reference the RA axis to the celestial pole, meaning that the scope RA axis rotates precisely around it, on the assumption that the scope is well balanced on the mount.

When setting the hour angle, I think I'm correct in saying that the 1 hour forward for BST is corrected for by selecting Daylight Saving when continuing with the Synscan setup.

Once Polaris is aligned it is essential to return the RA axis to the Park position, i.e. zero on the two RA scales, when the mount is squared up vertically - the scope dovetail will be at the highest point, perpendicular to the mount base. If you don't return it to Park, you will almost certainly suffer collisions of scope to tripod.

Now go through the Syscan setup and use three star align for the best alignment. If you have done all of the above, the target alignment star should be very close to the scope centre.

Finally; easy setup does assume overall optical alignment. I have done this in daylight by finding a distant object on the landsape, the further away the better. Set you mount up so that the polarscope is centred on that object, check its alignment by rotating the RA axis as detailed above, When you are satisfied with precise centering check to see whether the main scope is centered, you may have to tweak the declination axis. It may also be necessary to shim the dovetail rail to accomodate slight inaccuracies. Once centred, set the Dec ring to zero and lock it firmly. Then tweak the finder scope to centre the object.

Don't forget that leveling your mount is of primary importance.

You may need to consider PEC training and Cone Error set up, especially if you intend to do astro photography.

Get all this right, then you'll find that subsequent set up at different location is as easy as pie. Don't forget Lat & Long though!

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thommo10    23
Hmmm shame the hand controller (HC) is required to change the illumination of the polar scope, this means I now have to disconnect from EQMod, and reconnect the hand controller to get the illumination dimmer, then remove HC, reconnect EQMod again. Is the new dimmer setting then "saved"? or does disconnecting the HC reset it to it's brightest again?

I really want to dim mine too.

There is a small programe you can download from the EQ-MOD website called EQ DIMMER, I have turned mine down on my HEQ5 it took a while to find it but it is there.

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dark knight    31

Thanks Keith, I'll get looking for it right now. Why the manufacturer makes it so bright in the first place is beyond me.

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Photosbykev    2,132
Hmmm shame the hand controller (HC) is required to change the illumination of the polar scope, this means I now have to disconnect from EQMod, and reconnect the hand controller to get the illumination dimmer, then remove HC, reconnect EQMod again. Is the new dimmer setting then "saved"? or does disconnecting the HC reset it to it's brightest again?

I really want to dim mine too.

The LED brightness setting is retained in the mounts memory so you only have to set to the level you want once using the handset. Mine is typically set to 4% but I understand the very bright 100% led setting is an attempt to only allow Polaris to be visible throguh the polar scope under a dark sky?

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obscura    11

I recall seeing this at the start and it set me thinking. I developed my own way as follows.

Firstly, these first points can be done at anytime. Handset not required. Mount power not required.

1. Get Hour angle from eqmod, polar finder, Takahashi site etc. Read the dial as if it were a 12 hour clock (say 3:15) . Ignore the true hour angle

2. Reticle must be centred.

3. Mount as level as can be - but not to make it your life's work.

4. Set mount to home = weight bar at 6o'clock.

These points can be done in twilight as Polaris becomes visible on the polarscope. At twilight, reticle and Polaris easily visible. If it is dark, just flash a red torch down the polarscope tube momentarily.

A. Get Polaris anywhere in the reticle by bolts, mount move.

B. Using the az and el bolts adjust to get Polaris at its 12 hour clock time on the outer ring (3:15 as above).

Done!

Note that there is no swinging the mount here there and everywhere to get the little circle at 6 o'clock and where Polaris should be. Just reading the time and adjusting to that is the same. Its as accurate.

I have used this method for a while. Usually, assuming the mount remains unmoved, Polaris falls exactly in the right place time after time with no further tweaking. A bolt tweak may be necessary to confirm Polaris is under the outer circle!!! It will be.

Worth a trial?

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DrRobin    3,327

Hi, my mount is now on a pier, but I remove it every session. I find that my mount goes back in the same place every time and using the 'hour' time from the Synscan, Polaris seldom moves. Since Polaris is usually in the same place it is visible in even bright twilight and I can set the mount up in near daylight well before it is dark enough to be of any use.

I use the 12 hour method, gauging it through the polar scope and ignoring the dial, which moves slightly as the mount moves in any case. I find this quite accurate enough.

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obscura    11

Hi Robin.

Seeing that you are using the Synscan for HA why not use polarfinder etc. However, it did occur to me that you do not use eqmod. If not, give it a go. Haven't used my Synscan almost from new. Even then, I see that you do a polar align much the same way as I do except the source for the HA. But, I have that nagging memory that the Synscan HA is not accurate. I calc'd a while back that it was 15 minutes off. I queried it here in the lounge and that was the reply - Synscan is not an accurate HA. But then, 15 minutes? Will it matter that much? Probably not.

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