How to use an equatorial mount???

[wAi_kiT]

Haha, to contary, if I tighten the skrews, the RA circle will be locked on to the pointer, following the pointer as it turns. But if I loosen it, then the pointer will point to a new value as you said above! And if I turn the RA axis with that slow motion control cable, it doesn't matter if you tighten or loose the thumbscrew of the RA setting circle! So am I suppose to use the painted pointer in order to use the RA setting circle? CoZ only by using that painted pointer, everything will be according to what you've described...

[weixing]

Hi,

Haha, to contary, if I tighten the skrews, the RA circle will be locked on to the pointer, following the pointer as it turns. But if I loosen it, then the pointer will point to a new value as you said above!

Hmm... that's a bit odd... :? :?

And if I turn the RA axis with that slow motion control cable, it doesn't matter if you tighten or loose the thumbscrew of the RA setting circle!

What do you mean by this??

So am I suppose to use the painted pointer in order to use the RA setting circle? CoZ only by using that painted pointer, everything will be according to what you've described...

Suppose to use the metal pointer, but if the paint pointer work, then use the paint pointer lor... who care which one to use as long as it work

Anyway, the importance thing is that after you set the pointer to that RA value, the pointer must point to a new RA value as you rotate the RA axis... how this can be done is not that importance... at least for me... hee hee

Have a nice day.

[wAi_kiT]

Haha. OK ok.. Thanks Weixing!

[Star Newbie]

Hi there. I've come across this thread and it seems that I'm having the same confusion as I am very much new.
I hope this thread is still active?

My question is:
Isn't the "object's R.A. coordinates should stay constant and fixed when you follow and track the object?" "Or the R.A. pointer should read a new value on the R.A. Circle while you are tracking / following the same object?" If yes, why would it need to read or point to a new value? Isn't a star coordinates fixed at all?

I'm more confused now more than ever... Thanks hope to hear from you.

[weixing]

Hi,

My question is:
Isn't the "object's R.A. coordinates should stay constant and fixed when you follow and track the object?" "Or the R.A. pointer should read a new value on the R.A. Circle while you are tracking / following the same object?" If yes, why would it need to read or point to a new value? Isn't a star coordinates fixed at all?

Yes... it should read the same value when you are in tracking mode.

The reason for RA manual setting circle to be able to read a new a new value when you turn your RA axis is usually use for finding object or finding the coordinate of an object.

For example:
You want to locate M8 (Lagoon Nebula) and you know it's coordinate:
RA: 18h 04m Dec: -24d 20m
You also know the coordinate of Antares:
RA: 16h 29m Dec: -26d 25m

So you set the value of Antares's RA coordinate on your manual RA setting circle and lock it position, so that the RA value will not change when you turn your RA axis. You point your scope at Antares and unlock the RA manual setting circle, so that when you turn the RA axis, the RA manual setting circle will show the RA coordinate where the scope is pointing. Move your scope until the value on the RA and Dec manual setting circle match the value of M8 coordinate. Your scope should be pointing at M8 now.

You can also use this method to find the coordinate of an unknown object.

Have a nice day.

[Star Newbie]

Hi Yang,

I'm glad to hear from you. Thank you.
Maybe I quite get it a little but maybe my confusion is that I am mixed up with the term R.A. and the hour angle (?)
And maybe, my other confusion is on the "locking and unlocking the knob on the RA" My eq mount is just the simple and small one from Japan.

I'll try to repeat and understand what you just mentioned here and please see if I understand it a bit:

Given my polar alignment is correct.
I'll find Antares and once I have centered it in my field of view -
I would then set the coordinates: DEC: -26deg 25m RA: 16h 29m
And now, if I go and continue to track Antares - these coordinates should stay fixed and my RA circle "should not move or read to a new value, right?"

Now, after a while, I want to move to another object, say, M8
I would move/turn both axes (DEC and RA) until both the DEC and RA circles should read the value of M8 which is DEC: -24deg 20m RA: 18h 04m and if things are well, M8 should be found.


My other question if you'd still permit me to ask is:

What if I want to move to another object far away from the M8?
Would I be using and depend on M8 coordinates to look for the next object?
Or would I just simply drop and abandon M8 coordinates and instead go look for any recognizable star near "my next target" and do the same thing again as I did for the previous "Antares and M8 thing"

Best regards and thanks very much again.
S.N.

[weixing]

Hi,

Hi Yang,

I'm glad to hear from you. Thank you.
Maybe I quite get it a little but maybe my confusion is that I am mixed up with the term R.A. and the hour angle (?)
And maybe, my other confusion is on the "locking and unlocking the knob on the RA" My eq mount is just the simple and small one from Japan.

RA coordinate is in hour angle. Please note that the "lock" I mean here is not the RA axis clamp, but the lock for the RA manual setting circle (usually, a small thumbscrew at the RA manual setting circle... some might not even have it... depend ondesign).

I'll try to repeat and understand what you just mentioned here and please see if I understand it a bit:

Given my polar alignment is correct.
I'll find Antares and once I have centered it in my field of view -
I would then set the coordinates: DEC: -26deg 25m RA: 16h 29m
And now, if I go and continue to track Antares - these coordinates should stay fixed and my RA circle "should not move or read to a new value, right?"

You need to "lock" the RA manual setting circle, so the RA manual setting circle value will not change while tracking.

Now, after a while, I want to move to another object, say, M8
I would move/turn both axes (DEC and RA) until both the DEC and RA circles should read the value of M8 which is DEC: -24deg 20m RA: 18h 04m and if things are well, M8 should be found.

You need to "unlock" the RA manual setting circle, so the RA manual setting circle value will change before you point the scope at a new position. If your EQ mount RA manual setting circle cannot be lock, you need to set the current RA value again before you start pointing to a new position.

My other question if you'd still permit me to ask is:

What if I want to move to another object far away from the M8?
Would I be using and depend on M8 coordinates to look for the next object?
Or I would just simply drop and abandon M8 coordinates and instead just look for any recognizable star near "my next target" and do the same thing again as I did for the previous "Antares and M8 thing"

Best regards and thanks very much again.
S.N.

If there is a recognizable star near your next target, you can simply drop and abandon M8 as it'll be more accurate if you use a star nearer to the target.

Anyway, manual RA setting circle can't differentiate between you are tracking an object or you are pointing to a new object since it's just a piece of plate with marking and a pointer on it, so you need to lock the manual RA setting circle when you are tracking and unlock the manual RA setting circle before you point to a new position.

If your EQ mount RA manual setting circle cannot be lock, it's doesn't matter... you just need to set the current RA value before you start pointing to a new poistion.


Have a nice day.

[Star Newbie]

Hi Yang Weixing,

Thank you again for this wonderful piece and very very informative guide!
You see, I've been browsing a lot of forums on the net everywhere - BUT I have not come across about how detailed you've explained it here so far!

For that, I really thank you!

You see, this is probably the confusion among the newbies on using an EQ, just like the case of Wai Kit when he started this thread here.
I wonder , if he or she finally overcomes his EQ mount concern.

I hope this additional info which you have unselfishly shared here could also help other newbies on how to understand and use the Equatorial Mounts.

No wonder, I've been hearing about a lot of negatives from most newbies about using eq.

Okay, just to recap things for better and clearer understanding:

1. Both RA and DEC have "locks."

2. RA axis lock is different and separate from the RA CIRCLE LOCK - which is otherwise known as "thumbscrew."
NOW, most entry level EQ mounts may not and do not have this "thumbscrews" so that when you find an object and track it, the RA circle is detached from the RA axis and then the RA pointer points and reads a new value every time - as you continually track the object.
BUT if your EQ mount RA Circle has the "thumbscrew" you can lock the RA Circle to the RA AXIS so that when you track the object the RA coordinates should and will remain the same and will not point to new value.

3. NOW when you want move or go to your next object - you would have to UNLOCK the RA Circle thumbscrew - for it to be detached from the RA AXIS - so that when you slew or move the telescope through the RA and DEC axes (by the cables) to find your next object, the RA Circle would then read a new value - which is the value of your next object.
And if you're lucky after you have dialed in the supposed coordinates of your next object on both the DEC and RA axes - the object may very well be in the field of view.

4. BUT THEN, the fact is some mounts do not have RA CIRCLE thumbscrew lock.
And if your eq mount does not have one either - it doesn't matter.

So what actually happens if your RA Circle has no thumbscrew lock?
This means when you track an object (which is hourly) your RA pointer always points to a new value on RA circle.
WHY? Because the RA Circle is loose and therefore as you move your RA axis to track the object - the whole RA Circle or RA Plate is just simply "detached" from the RA Axis so it doesn't follow the RA axis as it turns. Which you would notice then that the RA pointer "points and reads" a new value on the RA circle plate - which probably captures and stirs your imagination and which adds to the confusion. BUT THIS ACTUALLY DOESN'T MEAN ANY SIGNIFICANCE. So just don't pay attention to it.

So that, when you decided to go to your next object,
you would then first need to "reset" the true RA value of the present object you are tracking simply by "turning the RA Circle or Plate" until the correct coordinates is being pointed by the RA pointer.

Yang Weixing, am I close and saying the right thing here? :o)
Thanks again, man.
you're very nice!

Best,
S.N.

[weixing]

Hi,
Please note that most EQ mount don't have lock for Dec... in fact, I think most EQ mount Dec is fix and cannot be adjusted. This is because Dec is fix... you just need to polar aligned your eq mount.

Have a nice day.

[Star Newbie]

Hi again Yang Weixing,

I meant "lock" on DEC axis - not the DEC circle.
Yes, I believe most of the eq mounts have fixed DEC.
But I've heard that a few expensive and bigger mounts have an adjustable DEC circle, is that true?

Have a nice day, too.
S.N.