EQ6 setting the scales ??

[thunor]

Hi there,

Great helpful forum to start.

My husband recently bought me an EQ6 and I've been going through the instructions on astrobaby's website (found these easier to follow even though its for the EQ5)

Astro Babys HEQ5 for Idiots Page

Can someone tell me if I only do this once for where I live or is this something I need to do at every viewing sessions?

Also Can someone tell me the purpose of doing this please??

Lastly do I have to do this outside at Polaris or can I do it using a terrestial object??

Thank you very much for your time.

[thunor]

Hope someone can help:)

[skye at night]

You shouldnt need to set up the whole mount everytime if you are observing from the same place...

You do initially have to

align the Polar scope to the axis of the mount.. this can be done during the day on a distant point... and is easier as you can tip the mount to nearer the horizontal to make this a comfortable job.

then set the zero point on the longitude scale.. which is just a reference point based on your timezone relative to grenwich..

These remain set unless you change position drastically...

You WILL however need to level your mount, polar align it, and balance your scope etc.. each time you set up...

Steve

[Bizibilder]

Hello Thunor,

Sounds like you are new to all this so I will try to keep this simple:)

Do I set up once? Yes IF you then don't move the mounting. This is why folks build fixed mounts / piers / Observatories etc. If you move it around eg take it indoors and put it out (with the cat!) to observe then you DO have to set up each time.

What is the purpose? Well, if you line up the polar axis to point to the north pole (very near to Polaris) an equatorial mount (like the EQ6) allows you to follow the movement of the stars etc across the sky by rotating ONLY the Polar axis. You will need to set up using Polaris (its the easiest way)

So: How to do it:

Put the EQ6 / telescope assembly in your chosen observing position. One part of the mount will have an "N" on it (usually near one tripod leg) this must face North - you may need to use a compass to find north roughly). The mount will probably only assemble one way so now the Polar axis is also pointing North.

You will find that you can make the polar axis move to point up and down at more or less of an angle to the horizontal. You need to move this axis until it points upwards at an angle equal to your latitude - there should be a scale on the mount to get this done ROUGHLY. The polar axis will now be pointing roughly at Polaris.

You are now well enough aligned to use the telescope for visual observations. (Even though the alignment is VERY rough )

Loosen both axis locks and point the scope at your chosen object (easier said than done if you are a newbie!!). Lock both axiis and then use the POLAR AXIS drive or hand control to track the object as it moves across the sky. You do not need to touch the Dec axis.

In reality - because your set up is only roughly aligned - you will need to keep making tiny adjustments the dec axis as well.

For better alignment you will have to follow the instructions given in the handbook. However if you can always place the telescope mount in EXACTLY the same place each session your regular minor adjustment should be very minor each time you set up.

For photography etc you will HAVE to set up accurately every time you use the telescope or get a permanent setup. (Which is why folk complain about spending an hour setting up each time )

My own set up is a roughly - as above - EQ5 mount in the garden. I tend to move it around at the moment so the only alignment it gets is a rough pointing at polaris - on a good day I get within 2 degrees!!!! I can then track easily enough for four or five minutes. Which is why I am building a permanent site.

I hope this is the sort of information you are after.

[thunor]

Thanks for your replies.

Thank you for going through that also Bizibilder.I think I may not have explained myself properly so I apologies.

I understand that I need to polar align for an EQ mount and that I will need to do this every time I set up.

But on the link in the OP it goes through something called 'setting the scales' where I have to use a program called polar finder and find when Sirius is in 'transit'. This is where I'd like to know why this needs to be done and if this will need to be everytime I set up the mount?

I will be using it for astrophotography so I understand the need to be spot on.

Thank you very much for your help.

[Parallax]

Yes, this does need to be done every time you setup. The reason is that Polaris (I assume you meant to write Polaris not Sirius) is not at the exact north celestial pole (NCP). If it were, then looking through the polar scope, you would put Polaris in the centre of the view. This means Polaris rotates about the NCP and that is why you have to offset it a little and put it in the little circle. And that little circle will need to be positioned in a different place dependent on date, time, location etc.

Having said all that, it is still not 'spot on'! It will be adequate for your needs to start with but later on you will need to come back here and ask about drift alignment.

HTH

Steve

[thunor]

Thanks for that.

So let me get this straight for astrophotography and being spot on accurate for relatively long exposures then stacking them....

Without laptop connected and using the synscan I need to :

• Adjust the polar scope reticule (or make sure its OK)
  
• Set the scales (Polaris in transit)
  
• Polar Align
  
• Drift align
  
• Two star align with the hand controller
  

With the laptop connected:

• Adjust the Polar scope reticule (or make sure its OK)
  
• Polar Align (very roughly)
  
• Use GuideDog or PHD with the QHY5 connected to my guidescope
  

There seems to be different ways to setting this mount up and its very confusing.

Thank you

[Parallax]

The method for alignment needs to be the same as your WITHOUT laptop steps. The reason being that, although you will be guiding, without proper alignment your (long exposure) images will suffer from what's known as field rotation. (Google this).

However, don't get too hung up on drift aligning and guiding at this stage - just get out there and have some fun. One step at a time.

You think that it's confusing now? Wait until you start taking images!

Steve

[Bizibilder]

Sorry Thunor, I had assumed that you were a novice having trouble with the concept of an equatorial mount - I just wanted to try and get you "set up and going"!

[themos]

The reticule adjustment is a one-off, or it should be. Its purpose is to make sure that the marked point on the reticule corresponds to the axis of rotation of the scope. You don't need to know where Polaris is, where you are or what time it is for this. It is best checked with Polaris in the view of the polarscope though since a) Polaris does not move during the few minutes it takes to check this and you will end up pointing the marked point near Polaris anyway.

So, you move the altitude/azimuth bolts until Polaris is in the centre marked spot of your reticule. Then you spin the RA axis 180 degrees and see if Polaris stays there. Adjust the reticule screws (3 of them, 120 degrees apart) until this is the case.

That's the reticule calibration finished, then.

I confess I don't use the scope dials for polar aligning. If I need to know the clock angle of Polaris with respect to the North Pole as seen in the guidescope I either use the constellation drawings on the reticule (Cassiopeia and Ursa Major) or the EQMOD laptop program that drives my mount. With the reticule constellations, you just look at the sky and see the orientation of UMa and Cas. Then you look in the guidescope and turn in RA until the view is roughly the same (these evenings it would be UMa on the left, lying down and Cas on the right, rising). That positions the little-circle-on-the-big-circle marking where Polaris should be. So, lock the RA and turn the Alt/Az bolts until Polaris is in the little-circle. Job done. With the EQMOD, it's a similar procedure: I put Polaris in the centre by adjusting the Alt/Az bolts. Then use the Alt bolt to put it in the 6 o'clock position. Then spin the RA so that the little circle comes down to the 6 o'clock position and lock the RA. Then I tell EQMOD that I've done that (that position is called guidescope home) and since I've told EQMOD where on earth I am and what time it is, it calculates where Polaris should be relative to the NCP. One more press of an EQMOD button and the scope gets rotated in RA so the little-circle goes from 6 o'clock to whatever the required position is. I use the Alt/Az bolts to move Polaris in the little-circle and I lock everything tight.

[skye at night]

The reticule adjustment is a one-off, or it should be.

I confess I don't use the scope dials for polar aligning. If I need to know the clock angle of Polaris with respect to the North Pole as seen in the guidescope I either use the constellation drawings on the reticule

Me Too...

seems to work OK.

Steve