TheSkySearchers

KathyNS wrote: ↑Tue Feb 21, 2023 11:46 pm Certainly it will do a meridian flip if the targets are on opposite sides of the meridian. De-selecting slew limits would prevent a flip when tracking a single object across the meridian. You cannot prevent a flip when going a goto to a new target: a goto will always send the mount to whichever side has the counterweights down. (In fact this is how software does a flip when tracking: it waits until the target is past the meridian and then just does another goto to the same coordinates. The mount knows to go to the correct side.)

Sending the mount to a counterweights-up position, which is what you get on the wrong side of the flip, is not recommended. You have to be very careful not to allow the scope to strike the tripod. The scope will get closer to the tripod as it tracks, increasing the risk of a strike with nothing to stop it.

You might want to deliberately send the mount to a counterweights-up position if an object is a short, safe distance before the meridian, which would allow it to track across the meridian without a flip. On that case, the tracking will return it to the counterweights-down orientation by itself, making it a safe thing to do.

hatflyer wrote: ↑Wed Feb 22, 2023 12:11 am This is shooting Orion, from Az=170 to Az= 240. I could wait until it gets to 180? Or is the range small enough that not flipping would seem ok? Altitude is below 45 degrees.

Thanks.

KathyNS wrote: ↑Wed Feb 22, 2023 1:43 am

hatflyer wrote: ↑Wed Feb 22, 2023 12:11 am This is shooting Orion, from Az=170 to Az= 240. I could wait until it gets to 180? Or is the range small enough that not flipping would seem ok? Altitude is below 45 degrees.

Thanks.

I am not sure now what you are trying to accomplish. I thought you had two different targets and were slewing from one to the other.

If you are finished with the first target at az=170, then you are finished with it. If the second target is at az=240, then let the mount go there. It will do it the proper way.

Not flipping is only an option when tracking a single target. And then, only for a very short time near the meridian. If you are switching targets, not flipping is not an option.

Juno16 wrote: ↑Wed Feb 22, 2023 12:33 pm Are you plate solving in NINA?

Juno16 wrote: ↑Wed Feb 22, 2023 3:16 pm Do you have the sync switch on?

hatflyer wrote: ↑Wed Feb 22, 2023 3:52 pm

Juno16 wrote: ↑Wed Feb 22, 2023 3:16 pm Do you have the sync switch on?

Not sure. Where is it, and what does it do?

Juno16 wrote: ↑Wed Feb 22, 2023 4:20 pm

hatflyer wrote: ↑Wed Feb 22, 2023 3:52 pm

Juno16 wrote: ↑Wed Feb 22, 2023 3:16 pm Do you have the sync switch on?

Not sure. Where is it, and what does it do?

The Sync switch is on Imaging - Plate Solving tab. Sync synchronizes NINA with the mount.

Just curious. Why do you do a star alignment at all?
Assuming NINA is set up (equipment information, location, etc), you can set-up a target using the Sky Atlas. Then send it to Framing (if custom Framing is desired). From Framing, add the target to a sequence and set the sequence Target options to Slew to Target and Center. That way, you will not to do any alignment at all. NINA will send the scope to where it thinks the target is then plate solve (with sync selected). Plate solving will adjust the mount to the target (based on the plate solve), then sync the mount to the target. The sequence can then be set to autofocus (if used) and then start imaging. All in one click.
I don't have the best cable arrangement, so when my scope just passes the meridian, I stop the sequence and send the scope to the Home position. I reset the sequence and start it again. NINA slews the scope the target (on the west side on the meridian) and plate solves, centers, focuses, and starts imaging again. Takes about one minute and I can watch for cable snags while the scope is slewing.
Hope that this helps.

Juno16 wrote: ↑Wed Feb 22, 2023 5:08 pm Absolutely! A single plate solve is enough. That is set in my sequence as the "Center" selection.
If you are imaging a target, the only point in the sky that you need to have the mount accurately pointing to and tracking is that target. There is no better way of centering a target than plate solving. Of course, the sync is part of it.

I haven't done a star alignment in years (many years). That is the way this type of software is intended to be used (NINA, APT, and I am sure that SGP and others too).

What method do you use for polar alignment? The NINA plugin Three Point Polar Alignment works extremely well.

Juno16 wrote: ↑Wed Feb 22, 2023 6:19 pm Polar alignment is aligning the mount to the celestial North Pole. Accurate PA is necessary for accurate tracking. I sometimes go with up to 3 arcmin and let guiding take care of it.

hatflyer wrote: ↑Wed Feb 22, 2023 6:23 pm

Juno16 wrote: ↑Wed Feb 22, 2023 6:19 pm Polar alignment is aligning the mount to the celestial North Pole. Accurate PA is necessary for accurate tracking. I sometimes go with up to 3 arcmin and let guiding take care of it.

Ok, I'm confused. Don't u have to use 3PPA to PA? You made it seem like you just slew to target, center and solve and sync and that's it.

Juno16 wrote: ↑Wed Feb 22, 2023 6:28 pm

hatflyer wrote: ↑Wed Feb 22, 2023 6:23 pm

Juno16 wrote: ↑Wed Feb 22, 2023 6:19 pm Polar alignment is aligning the mount to the celestial North Pole. Accurate PA is necessary for accurate tracking. I sometimes go with up to 3 arcmin and let guiding take care of it.

Ok, I'm confused. Don't u have to use 3PPA to PA? You made it seem like you just slew to target, center and solve and sync and that's it.

You must polar align prior to slewing to a target.
Polar alignment is totally different from aligning your scope to targets in the sky.
I assumed that PA’ed before you did a star alignment before slewing to a target for imaging.

hatflyer wrote: ↑Wed Feb 22, 2023 6:34 pm

Juno16 wrote: ↑Wed Feb 22, 2023 6:28 pm

hatflyer wrote: ↑Wed Feb 22, 2023 6:23 pm

Ok, I'm confused. Don't u have to use 3PPA to PA? You made it seem like you just slew to target, center and solve and sync and that's it.

You must polar align prior to slewing to a target.
Polar alignment is totally different from aligning your scope to targets in the sky.
I assumed that PA’ed before you did a star alignment before slewing to a target for imaging.

Ok, got it. I do do the slew to target and pain-in the-butt plate solve step after 3PPA.

hatflyer wrote: ↑Wed Feb 22, 2023 4:45 pm No alignment needed? I never heard of that. If u just slew to target and center, u are aimed correctly, a single plate solve is enough? No need to iterate through 3 point PA and ajusting the DEC and RA until the error is very small? Sounds too good to be true.