SGP and Plate solving

Hi all, I am have problems plate solving and getting the program to centre on the object I wish to photograph. plate solve works but The SGP program will just not centre on the object most of the time. I end up closing SGP and going to APT and I have no problems getting centred within 2 tries. Both programs use the same plate solve setting and software??? whats going on in SGP???
Please help. I am wasting hours at night trying to get SGP to centre with plate slolve
Using PS2.29, ZWOASI294, skywatcher, EQ35 goto,

You can test during day… open a sample image you took - right click plate solve.

Make sure image scale is correct.

Thanks for the reply I am getting it to plate solve but it will not centre the scope and sometimes the total error gets bigger until it fails to centre

Make sure location latitude/longtitude is correct in your mount software (I use EQMOD)

Slew to target first. Then try center here. (Right click on target in SGP)

Change # attempts to center to 5 in SGP telescope settings.

Yep done all that the funny thing is that I can close SGP and open APT that uses the same plate solve program and Astrophotography Tool slews to and centres on target almost exactly within 50 pixels


There are too many variables involved in centering. We would need logs to determine what is going on:

Ok I will get the logs and email the to you when I get home this morning. Thanks for your help. I really like the program and think it will be great if I can work out this problem. Cheers

on scope centering in the control panel under Plate solve, what number of pixels do you have the “until error is less than” set to?

If it’s to small it will cause this problem. I have mine set to 50 pixels and it quit doing that once I set it there.

Another thing you can try is parking it and then pull up an image, if you have one, from the last session that you shot this target and plate solve that image and check the box that says to use that solve for your target, and then try centering again.

Hi, I can’t get it any lower than 400 pixel and even then it mostly fails. I do a polar align then do 2 or 3 solve and sinks in different areas in the sky as a alignment then try to aim the scope at the nights target

What mount are you using when imaging if you don’t mind sharing?

Skywatcher EQ35Pro

here is a link to the files

Hmmm. Haven’t used that one yet. I asked because I used to have that issue with my NEQ6 a lot and fixed it with that last message I sent you. My NEQ6 had some issues pointing on the first slew.

My Losmandy does not have that problem.

Let me ask you this. Are you plate solving straight away without any kind of star alignment process first?

You shouldn’t have to because I never do, but maybe if you did a 1 star alignment and give your mount a little bit of help it would have an easier time getting closer to the target on your first slew.

I’m just wondering if maybe its a mount thing rather than an SGP thing.

Are you using EQMOD to control your mount? If so are you clearing out any old waypoints from previous nights that might be confusing the mount?

Not sure if any of this helps. Just brain storming.


Also make sure you’re using “Dialog Based” User interface in EQMOD under ‘User Interface’

I do an alignment first normally a plate “solve and sink” in 3 different areas of the sky
I also have been using APT before using SGP and I can get locked on to the target within 3 tries using plate solver, the same one that SGP uses with less than a 50 pixel error, if I can’t lock the target with SGP I close SGP and open APT and can lock on the target straight away, I find this odd as both programs are using the same “Plate solve 2” program.
I polar align using polemaster and the double check the polar alignment with Sharpcap to get polar alignment down to a few arc sec’s

Your’e not guiding while all this is going on are you?

I never do alignments with plates solving, just polar align.

Do you have the manual rotator connected? SGP likes that to be connected (Manual means you)

no guiding is disable while slewing and centering

ah, yes always

is that in SGP or on the mount itself