This guide is courtesy of an individual I discovered while researching my NexStar 8se. I have simply copied the information and given credit as to the originating source.


Before starting, you need to balance your 'scope tube away from the mount.

Having therefore placed all accessories, (finder, diagonal, eyepiece etc.) on the tube, rest it on a pencil on a flat, (table top), surface and find the point at which it balances. Mark the point and replace the tube on the mount arm so that there is a little fore-end weight bias.

Now with your 'scope switched on, select "Menu" and then "Scope Set-Up". Press "Enter" and then, by toggling either the 6 or 9 button, find "GoTo Approach".

Press "Enter" to find the "Azm Approach" which must be set to POSITIVE. Then similarly, find the "Alt. Approach" Approach". This might be set to NEGATIVE, the default setting. If it is not on default, set it so. You can always change it following experimentation at a later date. The purpose of this exercise is to get you up and running NOW !

As already mentioned, you now need to ensure that your anti-backlash settings are optimized for both the altitude and azimuth axes.

To achieve this, (and the operation can be carried out in broad daylight),keep you 'scope loaded with all usual accessories, (finder, diagonal, eyepiece etc.), level it and, as Venus is currently available in the daytime sky, perform a "Solar System Align" on this planet.

Note there is no need to seek it out, you are merely trying to achieve "Align Success" on the screen of your hand controller. This will ensure the 'scope is tracking which is necessary to anti-backlash adjustment.

Thus just point your 'scope to approximately where you think Venus to be at the (daytime) time and date you have entered, press "Enter" and "Align" buttons and your 'scope will be tracking thereafter.

Now slew your 'scope around and focus it on a distant brick wall or a tiled (shingled) roof. The idea behind using a brick wall or tiled area of a roof is to provide an improvised grid pattern on which to work.

Now select "Menu" and by means of pressing either the 6 or 9 button, select "Scope Set-Up". Press "Enter" once again and use the 6 or 9 to toggle to "Anti-backlash". Press "Enter" once again.

Let's assume that "Azm. Positive" appears on your hand controller's screen.

Press "Enter". A figure between 0-99 will be seen on your screen.

To avoid confusion in the centering of alignment stars/objects: if the Altitude GoTo Approach is set to Positive, (i.e. the fore-end of the OTA will be seen to rise when finalising its slew), then the said alignment stars/objects should be moved such that seen in the EP, they are moved from the top left of the EP's FOV, to the right and down, irrespective of how the directional buttons have been set or which combination is pressed. The watchwords are "As seen in the EP".

Conversely, if the Altitude GoTo Approach has been set to Negative, (i.e. the fore-end of the OTA will be seen to descend when finalizing its slew), then the alignment stars/objects should be moved "As seen in the EP" from the bottom left of the EP's FOV to the right and up.


Set your slew rate to 3 or 4 and then move your scope HORIZONTALLY ONLY across the brick or tiled grid pattern noting how long it takes before the 'scope begins to move, whether the movement is at all jerky in its action and whether, when you have traversed the grid by a reasonable distance, the motion stops when you take your finger off the direction button.

Move the 'scope several times back and forth across the grid in order to get a "feel" for what how it responds. If the drive take up is exceptionally slow, (and allow a few seconds here and there), or the motion is jerky either on drive take up or on stopping, adjust the shown figure in say, increments of 5.

When you are satisfied that you have a smooth action, that there is no great delay in drive take-up and that your 'scope stops when you take your finger from the direction button, then "Enter" the figure you have chosen and move to "Azm. Negative", repeating the exercise once more.

You should have now set both the Azm. Positive and Negative anti-backlash.

Now move to adjusting the Alt. Positive and Negative anti-backlash in exactly the same way but this time, moving the 'scope tube ONLY UP and DOWN. You will however probably find that the vertical (altitude) axis is much more sensitive in its response to adjustment of the Positive and Negative figures.

The above should now put you in a position to make accurate alignments.

ALIGNMENT:

Choose the "Auto Two Star" method. (This method appears by consensus, to be the most reliable).

Thus with your 'scope tube pointing North and with the mount arm on your left as you stand behind the instrument. Switch on your 'scope and enter all relevant data, Time, Date etc. (I assume from your previous posts that you are acquainted with the procedure and the necessity for the relevant accuracy here).

Irrespective of what your hand controller offers, choose Polaris as your first star. (I make the assumption that you can see it). If it is not the first star on offer, you will need to toggle either the 6 or 9 buttons to produce it on screen.

Now locate it in your finder and, having done so, press "Enter". You should now see it in your eyepiece, (a 25mm will be quite sufficient), although it may not be in focus.

Keep it defocused as I think Francois suggested, so that it looks rather like a large doughnut. This shape allows you to centralize it in your eyepiece far more easily since your eye is very susceptible to the concentricity of rings.

Thus, by comparing the position of the doughnut with the edge of the field of view, you should be able to centre it very accurately.

However, the doughnut may not be in the the centre to start with. No matter ! Using the direction buttons on the hand controller, move it to the bottom left quadrant of your eyepiece.

Now from this position, move it right and upward to centralize. If you overshoot, take it back to the bottom left quadrant and begin again. When you are satisfied that you have it centralized it, press "Align" and you will be offered your second alignment star.

This star should be between 30 and 70 degrees in altitude and at least 90 degrees from your first choice; Polaris.

Let's assume it has chosen or that you have chosen Altair.

Press "Enter" and your 'scope will automatically slew to this star. If it "lands" nowhere in the vicinity of Altair you will know immediately that something is wrong, but all being well it should be near. Now merely go through the same procedure as you did when aligning Polaris and you should have a good alignment.

Note that your 'scope will be now tracking in sidereal time and that the "Cordwrap" feature will now be "On" by default. (I choose to operate with it "Off" but I leave that to you. If you leave it "On", you may need to set a "No Cross Line").

Now for the GoTo and tracking performance of your 'scope.

If your alignment has been successful, any object you "GoTo" should be within the field of view of a 25mm eyepiece although not necessarily in its centre. Thus if you wish to bring it to centre, (as is normal), use the same movement (bottom left to the right and up) as used when you aligned, to do so.

There is a caveat however:

This procedure should keep your 'scope tracking well when operating between North and South through East but you may find that objects may begin to slip from the field of view in very short time when operating the 'scope between South and North through West. If this occurs, simply align or realign the "slipping" object by placing it in the UPPER left quadrant of the eyepiece and recentralizing it by moving it to the right and DOWN.

Just perhaps to clarify however:

To avoid confusion in the centering of alignment stars/objects: if the Altitude GoTo Approach is set to Positive, (i.e. the fore-end of the OTA will be seen to rise when finalizing its slew), then the said alignment stars/objects should be moved such that seen in the EP, they are moved from the top left of the EP's FOV, to the right and down, irrespective of how the directional buttons have been set or which combination is pressed. The watchwords are "As seen in the EP".

Conversely, if the Altitude GoTo Approach has been set to Negative, (i.e. the fore-end of the OTA will be seen to descend when finalizing its slew), then the alignment stars/objects should be moved "As seen in the EP" from the bottom left of the EP's FOV to the right and up.