I just got my first equatorial mount (ZWO AM5). I really dont know much about the setup of the mount other than I have already adjusted it for my latitude (altitude adjustment). What I have read, is before I can start using SGP for guiding and plate solving I must do an polar alignment. Can anyone give me some very simple instructions or point me to where i can get these instruction on how to do a polar alignment. What I have read is contradictory between different web sites. Any help is greatly appreciated.
Before doing any sort of imaging you need to polar align; its not just unique to using SGP. Polar alignment, as the name suggests, aligns your EQ mount’s RA axis with the axis of Earth’s rotation, whether it be the north celestial pole in the NH, or south celestial pole in the SH. The mount is designed to counter the effects of Earth’s rotation by moving your imaging rig at the same rate as the sky appears to move overhead, allowing you to do long exposures at long focal lengths without the stars appearing to trail in your images.
Some mounts have built in polar alignments scopes, though it doesnt appear that the ZWO one does. I believe the ZWO scope is designed to be used with the ASIAIR which I think has a built in polar alignment routine, which likely explains why the mount doesnt come w/ a PA scope. That said, you don’t need an ASIAIR to do the alignment.
I believe the SGP devs are working on a PA routine for SGP so when that’s out, you can use that. Until then however, you could use something like sharpcap which you can download and run the polar alignment routine, or what I did was get a Polemaster which is a small camera that attaches to your mount and using the included software walks you through a very straightforward, VERY accurate polar alignment. Theyre a few 100 USD, but in my experience well worth the price of admission, and when SGP releases its own PA routine, you can just sell it for most of your money back.
I just had a thought, I am using an OAG and an asi120 mini for my guiding camera. Will that work just like polemaster camera to do a polar alignment? I do apologize if any of this dream obvious but I’ve never done anything like this before
No, the Polemaster takes a wide field image of the pole, rotates the mount, then takes another wide field image to calculate the offset (the iOptron iPolar works in the same manner). Your guiding camera only corrects images for drift when it sees the drift happen and does not help to polar align the mount.
Polar Alignment is often misunderstood, especially when first starting out with astrophotography. But once you understand what is happening it’s a pretty easy concept to get. Polar Aligning is aligning your MECHANICAL access or rotation (The RA axis) with the rotation of the earth.
Your guider can help to correct some amount of alignment error BUT if your alignment error is large enough then you’ll get field rotation due to the alignment error. In the case of an OAG you actually need to have more accurate alignment as field rotation will be centered around your guide star and since you’re guiding away from the center of your image you’ll have more visible field rotation in your actual image.
And yes, we are currently working on a Polar Alignment solution in SGP. No ETA at this time but it is under active development.
Jared, Hopefully the polar alignment routine will come soon as it’s the sole reason i left SGP for another platform. A polar alignment tool should be considered an basic essential tool, and am surprised it’s taken SGP this long to start working on it, given that this functionality has been available in other platforms for quite a long time now.
Please note that his is not a criticism, I would just like to see some of these features start appearing in SGP then i can consider switching back as i like the interface layout of SGP, but i’m just not willing to pay a subscription until these tools start to appear in SGP.
There are some polar alignment tools in PHD2. I’ve never tried them (was using PemPro at the time) but someone had an issue with not being able to see the pole and PHD2 was my suggestion. He reported back his appreciation, said he could polar align in 10 minutes (I was taking 30 because my sensor was so small) and for all I know he was way more accurate.
Lately I have been using an iOptron Polemaster equivalent; love it but you need to see the pole. I have a mini PC like you. i take my laptop down to the scope, remote in and use the align program in the mini PC. I think QHY makes Polemasters for a lot of scopes.
I just looked at a ShaprCap polar align video: same basic concept with your scope mounted camera.
@Jared Hi! Has there been any progress on the polar alignment routine in SGP? I have just invested in a ZWO AM5 mount as an alternative to my EQ6R mount. The AM5 mount works fine with SGP via ASCOM, but I need some way of achieving polar alignment not dependent on ZWO ASAir which I am not using. So any news on this?
We have indeed made progress, but it is currently on hold as we have prioritized an array of quality of life and user issues ahead of it and cannot do both at once.
A quick screenshot of the progress here shows the general interface and how users will receive movement instructions.
