Scope balance and drift aligning

[E_ri_k]

Hi. I have a HEQ 5 mount and a 1200mm x 254mm reflector. I am in the southern hemisphere and have chosen to drift align my scope because using the polar scope seems impossible! My question is regarding balancing the scope:

From reading the manual it says to balance the RA first by setting the latitude to about 30. Then the DEC by setting the latitude to around 70.

Now, my question is, does it matter weather you balance the scope before or after polar alignment? Because I am fiddling with the altitude adjustment while drift aligning?

[obscura]

After. You need to polar align with a naked mount using the HEQ5's polar scope. Balancing in both RA & Dec should be done with scopes, cameras etc mounted and pointing roughly around your target observing point. If you are dift aligning then, I would say, same procedure before drift align.

[E_ri_k]

Ok, so align mount, decide what i'm going to view, and then balance according to where i'm pointing at.

[obscura]

That's about it. Polar align, balance in and around target. Weight RA slightly - here its likely to be on the East side of the mount. I guess there it'll be on the West side? This is to help prevent the mount over running and joggling around target. I.e. Tweak one of the weights a little downwards for this to keep the mount's gear train in drive.

I haven't drift aligned as yet but will later this year. Drift align as far as I understand is close on essential for imaging, but not so much for visual observing. The HEQ5's tracking isn't bad but may an occasional NWSE teak. (I assume your HEQ5 has the Synscan - i.e. Pro version). That's a lot of scope on the HEQ5.

[andrew s]

Not sure I fully agree with the above. Firstly an equatorial mount should be balance in 3 planes. 1) about the RA axis with the dec axis horizontal. 2) about the Dec axis with the dec axis and the tube horizontal. 3) about the dec axis with the dec axis horizontal but with tube vertical. Once balanced you can add a small imbalance to keep the RA worm engaged. Then align with all he weight on the mount.

Andrew

[E_ri_k]

Thanks 'oldgit' for the info. Yes the RA is weighted to the West down here. My mount has the SynTrek handset, not the GOTO SynScan. I also thought the scope was very heavy for the mount, as I have had to add another 8KG to the supplied weights to balance. Seem to have it pretty balanced at the moment.

In reply to andrew s; I have balanced the RA with the DEC horizontal, and then the DEC with the tube horizontal, but not the last one with the tube vertical.

Tried doing a drift align tonight, but frustrated the hell out of me! I was pointing to the West to check for drift. The star drifted South so I raised my latitude. Had it pretty good at around latitude 36. Chose a new star in the West, and now it drifted North, so I thought, ok, lower the latitude. Had it pretty good at 29 degrees now??? Dont understand how it can be good at different settings?

I must be doing something wrong, but not sure what?

[obscura]

Think the mount is on its limit. Obviously NEQ6/EQ6 would be better but, what a price! Keep it balanced. Well, as I said I haven't attempted drift align as yet so cannot really advise. There are drift alignment procedures here on SGL and on the web. Try dialling it in - may well help - or open a new thread here specific to drift align - help!

May I advise grabbing hold of "Making Every Photon Count" by Steve Richards. Its about £20 but it'll be the best £20 you'll spend. Although aimed at astrophotography for beginners it covers everything from alignments to imaging with DSLR/CCDs. An absolute mine of info that appears to be the bible of many in SGL. Highly recommended.

I'd be interested to know how you get on - my turn in a couple of months when the nights get darker (and colder)

Good luck

Rgds

Brian

[JohnnyD333]

Hey Erik,

I think a quick drift alignment is impossible. Whenever I read about drift alignment or attempt it myself, it can be very time consuming. Just be patient with your method and keep going. Get Steve Richards' book if you can, Oldgit is right about how essential it can be.

[E_ri_k]

Ok, thanks for the help guys. I will have a look at that book, and spend some more time on it I guess.

Thanks!

[andrew s]

Are you sure the mount, tripod or pier are absolutely rigid and the ground firm underneath. If not their movement will frustrate your efforts. Andrew

[E_ri_k]

Yeah Andrew, I had the tripod set up on my back deck, and the vibrations from even moving my body the slightest bit transfered to the scope, and was amlified hugely! I have moved it to solid ground and re balanced it. Only had it on the deck as it gave me a better view of the sky. Going to do a drift align now that it is solid, just for practice, then think about building some sort of permanent "observatory", and re aligning it.

I will let you know how I go!

[andrew s]

Hope it goes well. Don't forget it is an iterative process. Alternate between adjusting the Alt and the Az as they interact especially when you are not yet close to the pole. Andrew

[Shibby]

Hi Erik,

Having attempted drift alignment myself a few times, I can echo your frustrations! I often found myself at a point when everything I did seem to increase the drift. 2 things it took me a while to get into my head:

• Level your mount first. This will reduce the number of iterations you need to do.
  
• Check your reticle is rotated correctly using the E-W movement of the mount while you're looking through the eyepiece.
  

There is a superb simulator here: Classic Astrophotography - Photographing the Cosmos with ordinary film

Using this, you can practise to your heart's content rather than wasting valuable clear sky time!

Good luck!

[obscura]

Thanks for the link Lewis - that's going to be a great help when I get to it later this year.

[E_ri_k]

Yes tried the drift sim. Seems straight forward. I think I know what I have done wrong. Kind of stupid really, but when I tried aligning the azimuth I had to point my scope at a star on the meridian near the equator. I pointed my scope south....Thought about it after and I should have pointed it North! The celestial equator is below the horizon for me if looking south. That's why the drift was all over the place I guess.

[E_ri_k]

Drift aligned last night. Worked great. Needs some tweaking, but got no noticeable drift for 10 min or so.

[obscura]

Excellent. Just 10 mins! The sim is v. good - there's nothing like visuals. Gives me encouragement for later this year.

[E_ri_k]

yeah I know 10 mins is not great. Probably got a periodic error. haven't got correction for that on my mount. Will keep making it better!

[obscura]

Ooops! Sorry, I misread you into thinking it took 10 mins for the drift align! Must learn to read. Even then, 10 mins ain't bad for a first go - I'd be pleased with that.

Found another site that looks quite useful :-

www.astrophotography-tonight.com

Rgds

[E_ri_k]

Haha, all good. Yeah its not bad. Got a couple of good piggyback shots of the milkyway. Would like to perfect it for much longer exposures.

[E_ri_k]

Got some photos tonight with the camera piggybacked!

Probably nothing special, but I'm pretty happy with them as a first attempt!

The are all about 2 and 3 minute exposures on my DSLR.

[andrew s]

Glad you have got it working. These look like very an excellent first attempt. Andrew

[E_ri_k]

Thanks! Still not perfect. With longer exposures the stars start to streak a bit. Getting bad weather at the moment, so will have to wait for it to clear, and my camera battery went flat....

[andrew s]

However well you polar align you will need to autoguide to keep the stars round with long exposures. Atmospheric refraction and any errors (short or long term) in the mount will build up to blur or elongate your star images. Andrew

[obscura]

Excellent, you are on your way! Agree with Andrew wrt autoguiding.