How To Use An Equatorial Mount

In by entries in this blog we take discussed the merits Equatorial Mounts vs Altazimuth mounts on telescopes, merely we never really went into much 016 particular on how to properly use one of these mounts. Here are some bones hints for a beginner outset trying to use an equatorial mount. Note that this are not hints for precision alignment – they are strictly for the beginner so they exercise not go overwhelmed! Speaking of which

one) Go along you mount setup as simple equally possible at start.

Await at telescope instructions for equatorial mounts and you'll see a lot of information on adjusting setting circles, using a polar axis scope, and other heavy duty details. Hither'southward a hint: If you don't program on doing astrophotography or long, long viewing sessions you don't need all of that setup! Here is what yous need to practice:

2) Set the latitude scale to your latitude and aim the polar axis so information technology points north

That's a lot of words there, only we'll simplify, and use pictures! First of all you need to ready your mount's alignment to match your location on the globe. The alignment is fix from the breadth scale on the side of the mount, ndear the bottom. Here is where information technology is on a small telescope:

LatitudeScale

In that location's three small parts to this. First is that arrotw thing pointing at numbers. You desire that arrow to signal a number that is very, very shut to yous ain personal latitude. Get and go a map if you need to. We hvae ours set at 40 degrees because that is the latitude of our store in Philadelphia. Or at least it is close to that.

The next part is to aim the mountain so that the Right Rise axis is aimed north. This helpful picture will point out which function of the telescope that is.

PolarAxisShaft

Point that shaft (subsequently adjusting the latitude) north. Endeavor to be as accurate as possible but don't get hung up on information technology, use a compass to help out.

Once you've done that, congratulations! You have done a basic polar alignment! What this means is that shaft you aimed is now paralell with the Earth's centrality and if you were able to wait through it, information technology would exist aimed roughly at the Due north Star (polaris).

This is a rudimentary alignment and is perfectly acceptble for most beginners. If yous motion into more than avant-garde things like astrophotography you will need to be much, much more precise in your alignment.

OK, so that was easy just now is the hard part, you lot have to alter how you recall about things:

3) End thinking in terms of upward & downwards, left & right, offset thinking in terms of Right Ascent and Declination.

OK, so an altazimuth or Dobsonian telescope moves in upward/down left/right, which is easy to effigy out, but lousy for tracking. Equatorial telescope move in Correct Ascent and Declination, which is a bit harder to sympathise.

Basically, if you watch stars in the sky move (or seem to motility as the World rotates) you lot will observe they move in an curving arc through the heaven. By setting upwardly your telescope as in part #2 you accept set your telescope and then that it can rail those objects equally they move. The trick is now you need to move the telescope in Right Rising and Declination, not up/downwardly left correct. This is a alter of mindset that you will need to adapt to employ the mount properly. The graphic may help with unders AltazvsEQTElescopes tanding it (although we had to use a directly line instead of a curve for Right Acension).

Then when you are on ane celestial object and need to move it to some other y'all can't just become "a little to the left, then signal the telescope up a lot more it is at present. You have to movement the telescope in Right ascent, then motion information technology almost diagonally in Declination to get on target. This can be frustrating to learn. With larger Equatorial mounts and a Star Atlas this tin be easier past simply 'aiming with the setting circles', but setting the setting circles up complicates things more than nosotros are trying to do for this blog postal service.

And then year, y'all will have to practice this type of motion until get used to it. Merely go on in heed that every bit you motility your telescope you might notice something:

iv) Your Equatorial mounted telescope will never, ever look like it does in the catalog while in apply.

OK, so call back this pic from the top of this blog entry?

Yes, that one.

Well it is something of a lie. A big fat lie.

Oh, it looks nice. The telescope looks at its near attractive in that position, which is why almost every EQ telescope from every company shows it in that position.

Believe me, they have tried to show it in other positions, but it but is merely not photogenic at all.

See hither's the thing: Did you lot find that big weight sticking on a pole down from the telescope'south tube? That is called a counterweight and information technology is there to balance out the weight of the optical tube as it is beingness aimed. But in that position shown (pointed straight down) it isn't doing anything!.

Because in reality, the telescope will more oftentimes look like this (or at least aimed like this if it were exterior):

POintedWest

This is of course, shot indoors, just it give y'all an idea of how the telescope mightbe aimed. This is shot from the front end (North) of the mountain so the telescope would be pointing West. Now the telescope's coutnerweight is actually doing something, only it would be doing even more if the telescope were pointed N or Due south, because the it would look like this:

Now the counterweigh

LookingNorth

t is really doing its job.

Then, about moving the telescope'south into position:

5) Utilise the slow motility controls for when you are close to your target, motility the telescope past loosening th

e lock screws for annihilation larger.

OK, so you might have noticed these spindly plastic knobs extending from the mount. Here, we marked them on this movie in blood-red.

These are the slow motility controls, they allow you lot to aim the telescope, and the one in Right Ascension will allow you lot to track an object equally it moves through the night sky with the turn of its knob. These things are crawly and one of the main features of a Equatorial Mountain.

And you should only employ them one time yous are very close to being where the object is you are viewing.

The boring motility controls tin can't move the telescope very much – they can go a few degrees merely and so they volition reach their limit and won't movement the telescope any more. You should attempt to avoid reaching this limit as it is hard to backtrack and you might need that slack afterwards on.

Then for larger movements information technology is better to loosen the lock screws (marked with blue arrows (at to the lowest degree the ones still in the picture)) and move the tube by paw, roatating in in R.A. and Declination as needed. In one case y'all are close to the target object, tighten the screws (critical!) and utilise the slow movement controls.

These hints should give you a rudimentary idea of how to operate your equatorially mounted telescope. There is a learning curve here and y'all will need to arrange to it. But the benefits make it worthwhile, articulate skies!

Slowmotion