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Polar Alignment Made Easy...... ish.


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After all the talk over the past few days regarding Polar Alignment things have got very technical. Most of it is very very simple and should take next to no time to achieve. Finding all of the information took a while and involved looking at a great number of posts, websites and videos. So here it is in simple steps.

1, Centralise your polar scope reticule.

I am not going to cover this, but this link explains it very well. Do not be fooled, it is easy in theory, but in practice very akward and frustrating. A little at a time is the only advice I can give... the link: http://www.youtube.com/watch?v=BS43vH_sDbg&feature=plcp

2, The parts we will be using.

RA Ref Mark, this is where we will set up to initially to give us a starting point.

Time Markings, there are two sets of numbers, both represent the time of day in 24hr mode. The mount when in normal tracking mode for the northern hemisphere will move anti clockwise from this view, so we use the top row of numbers, ie am to the left, pm to the right.

Date Markings, these are the date, each line represents 2 days. Self explanitary I hope. This ring or plate moves with the RA of the scope and polar scope, but can be moved with your fingers as it is not positively attatched.

Marker Ring, This ring sits over the polar scope and is secured with a grub screw. There is a white line on mine, there will be something similar on yours. We can use this to indicate where in it's rotation the polar scope is.

Polar Scope, This is the little devil that most people fear.

3, Setting Polar Transit.

Polaris moves about the Celestial North Pole. When it appears at it's highest point in the sky, we call this the Polar Transit. As polaris moves around CNP wee need to know exactly where it should apear in the polar scope so we can accurately set up and align the mount. We use the Polaris Transit for this when we don't have access to a laptop and program such as Polar Finder. This is also a slightly more acurate method unless you have fancy control software etc to set it up for you.

Polaris Transit is when polaris is at the very top of it's orbit of CNP, so, in a polar scope that will look like the bottom. So we undo the RA clutch and rotate the whole mount in the RA untill the reticule shows the little circle at the very bottom:

With the reticule in this position lock the RA clutch and DO NOT MOVE THE MOUNT.

Next undo the marker colar

And spin it WITHOUT MOVING THE MOUNT to line it up with the RA Ref Marking

Now we need a time and date when polaris is at transit. One such time is around midnight on 1st Nov. This is true for any nov 1st. In London at 0 deg latitude it is actually 23:45. It occurs approx 5 mins later per 1.5 degrees west you are of London, and 5 mins earlier per 1.5 degrees east. For example, here in Derby we are approx 1.45 degrees west, (1.5 is close enough) so 23:45 plus 5 mins is 23:50.

So in Derby, at 23:50 on the 1st Nov, Polaris will be in transit.

With our reticule at the bottom, and our mark now at the top lined up with the RA Ref, we can now set our Transit time and date. WITHOUT MOVING THE MOUNT, revolve the date markings so that 1st Nov points to 23:50 (if you are in Derby) These two marks should line up, I know they don't in the picture, but these are the two I am lining up.

Now we have a starting point which we know is correct. (within a few minutes)

4, Setting the reticule for the time and date of use.

Now the reticule is set to polaris transit, and our date and time are set to a known point, the only thing we need to do now is set up for the time and date we are using the scope, or more importantly the time and date we are polar aligning.

Important to remember that the time is indicated in GMT form, so if it is summer you need to take an hour off the time you are setting it to.

So say for instance we are setting up tonight 2nd Aug at 23:30, we need to set up the dials to 22:30.

WITHOUT moving the date circle in relation to the RA or polar scope, undo your RA Clutches and spin the mount until the date and time (in GMT) are lined up, then lock the clutches.

Your polar scope reticule is now in the correct position for the time and date you are aligning up on/at. Using the bolts, not the slow motion controls adjust untill polaris appears bang in the middle of the little circle on the larger circle. Do not allow the RA to alter until after you have aligned, or you will need to go back to transition and start over from there.

I hope this has made some sort of sense, it does to me, but I know what I mean, so it would make sense to me I guess.....

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Nice write up Mike, never knew any of that, so understandable now why I could not help Sheila!

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Good write up there Mike.

Clearest instructions I have read to date.

Award yourself 10 clear night credits.

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Thanks Mike for this amazing post, makes complete sense now with pictures to aid :) Top man you deserve an award :)

I've got mine all setup and I KNOW it's right as this all makes sense :D

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