Plate Soving with Star Alignment Help. Is it worth it?

Normally each night I just click center here on my first target and let it plate solve on to the target and start imaging.

I never do a star alignment first.

My question is would my mount track better and give me better guiding if I were to do a good star alignment before I plate solve onto my target.

My reasoning for wondering about this is that my mount is always off by about 4000 pixels when starting out fresh at night. As I move from target to target through plate solving it drops a sync point in each time and gets the mount better aligned. This results in me usually being off by only 200 pixels when I go to center on the third or fourth target.

So I’m wondering if I were to do a good star alignment prior to my first plate solve and get the mount better centered would it then translate that into better tracking and thus give me better guiding?

Seems to me that if the mount had a better idea of where it was then it would not have to work so hard to provide corrections as it tracks.

Am I off here?

It wont change guiding charecteristics, it will however allow the centering routine go quicker.

I don’t do star alignments any more either unless I had to move or take down the rig. I do however do a solve and synch first.

No, this has no bearing on mount tracking at all. guiding/tracking and
pointing accuracy (plate solving/sync) are two different things.

What I do is slew to a random star in the sky then do a solve and sync.
That tells the mount exactly where it is pointed. I also don’t do star
alignments at all anymore.

Thanks guys. I kind of figured that was the case.

This is the kind of things I start thinking about at 2am while sitting under the stars smoking a cigar and imaging.

Fun Stuff

If your 4000 pixel misalignment is due to a polar alignment error, and if you fix that, it will certainly improve your tracking. But if your polar alignment is good, then a one-star solve and sync, as Joel said, is all you need.

Best regards,

Thanks for the input. I thought about sending my NEQ6 to Dark Frame in Europe for tune up and other upgrades but when I can just get on target with Plate solve and get 20 - 30 minute exposures with nice round stars, I ask myself What’s the Point?

Because of the mount being off by so many pixels at startup it usually takes three iterations of Plate solve to get it below 50 pixels, but after that initial Plate solve it will usually get new targets in 2 iterations.

That’s why I was just thinking that maybe a star alignment would help it but that’s all it was . Just a thought.

Thanks again guys!!

Building a model is really only useful if you’re in an observatory or if you plan on taking multiple short targets. If you’re mobile don’t bother. Just select both the “Slew” and “Center” options on your targets and SGP will slew first then center. This will get you close to the target and make the Center more accurate. It also has the bonus of making sure you don’t sync very close to the pole which is almost always a great way to make things go poorly.


Yeah that’s what I’ve been doing. Works like a charm. This question was just me thinking how to make things tighter.

I tell ya my biggest problem is the stupid ascom driver for my Lodestar X2 dropping out in PHD while I’m away or sleeping and then killing the sequence and having it abort and park.

I first thought that it might me the dither command coming from SGP but I shut it off last night and it did it again 3 times. Driving me nuts.

When I look at the log files I can never see the actual point of failure. I just see a message saying something like ascom failed due to prior error.

Not sure what to do. I have reloaded the drivers twice and everything else I can think of.

The USB connection on the back of the Lodestar seems pretty touchy. I’d zip tie the cable to the lodestar or some other fixed area. If mine moves around too much I also get disconnects.


Phd2 also has a native driver for the Lodestar. This worked better for me than the ascom one.

Ditto on the native Lodestar driver - I’ve had better success with it vs. the ASCOM driver.

Also, the Lodestar X2 usb port does not seem to have the same level of “touchyness” as the original Lodestar. But still a good idea to zip-tie the cables around the cam/focuser.