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Aligning with Polaris, Polar Alignment, and Error plate solving with ASIAIR

Astrophotography EAA Equipment
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#1 TrickQuestion79

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Posted 26 January 2022 - 01:15 PM

I wanted to start off with trying to align my mount in the direction of polaris. When I estimated the mount pointing at polaris, I looked into the built-in finderscope for my mount and I saw nothing. Any idea why? So, if I'm correct, I'm supposed to set my mount at the correct latitude for my location because trying to polar alignment. How do you go about doing this?

 

For polar alignment with the ASIAIR pro, I tried all different kinds of exposures but each time I end up with an error. Well, it's for plate solving because it says, "FOV out of range 0.2degrees-33degrees " or something like that. I know I made another discussion post about platesolving with the asiair, but I wanted to make a new post including polar aligning without the air. Anyways, I tried all different kinds of exposure lengths with and without the Bahtinov mask, I set the focal length to 250mm(I have the Redcat 51) and tried setting it at 0mm. Also, with the Bahtinov mask I took a 2 second image preview; how do you bring it to focus after seeing the preview? You have to use the focus index on the redcat right? How slowly should you change the focus on time? Maybe I should just mess around with it and see what works?

 

Lastly, on the air, if I put in the l-extreme filter, how would it affect the previewing on the asiair? Just curious.

 

 



#2 lattitrail

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Posted 26 January 2022 - 01:34 PM

Setting latitude:

 

If you lived on the north pole, latitude of 90, the celestial pole would be at 90 degrees. you would set the telescope mount's latitude to 90. If you lived on the equator, latitude of 0, the celestial pole would be at 0 degrees, and you would set your telescope mount at 0

 

As you can tell from these examples, the latitude of the mount is always equivalent to the latitude of the observing location. As such, you want to set your mount at the same latitude as your location. For me this is 40 degrees north, so my mount is always set at a latitude of 40 degrees. There should be a degree setting on the mount somewhere around the latitude adjustment that will give you a close approximation, but likely won't be exactly accurate..



#3 TrickQuestion79

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Posted 26 January 2022 - 01:41 PM

Setting latitude:

 

If you lived on the north pole, latitude of 90, the celestial pole would be at 90 degrees. you would set the telescope mount's latitude to 90. If you lived on the equator, latitude of 0, the celestial pole would be at 0 degrees, and you would set your telescope mount at 0

 

As you can tell from these examples, the latitude of the mount is always equivalent to the latitude of the observing location. As such, you want to set your mount at the same latitude as your location. For me this is 40 degrees north, so my mount is always set at a latitude of 40 degrees. There should be a degree setting on the mount somewhere around the latitude adjustment that will give you a close approximation, but likely won't be exactly accurate..

Are you talking about this compass? How do I change the latitude settings on the mount? Do I use the azimuth adjusment knobs? Also, can I just use my air to collect the data about my latitude/longtitude, and set it at home position; would it automatically go to the the right latitude?
 
eq6r compass


#4 unimatrix0

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Posted 26 January 2022 - 01:51 PM

 

Are you talking about this compass? How do I change the latitude settings on the mount? Do I use the azimuth adjusment knobs? Also, can I just use my air to collect the data about my latitude/longtitude, and set it at home position; would it automatically go to the the right latitude?

 

That's not a compass. Your mount will not go to your right coordinates. 

That's your latitude adjustment. You adjust it with the front and back levers. It has to match the same latitude of your location . You can look that up with your smartphone compass app or just google "my latitude". It has to be the same, although having bumps and hills and the mount not being perfectly level can effect what number is dialed in . 

Please watch this video
https://youtu.be/plx6XXDgf2E


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#5 drotto25

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Posted 26 January 2022 - 01:51 PM

Yeah, the mount degree is a rough guess. I live also at about 40, just a little over in fact. I have a GEM28 and the degree marker on the side (this one is printed on) says I am at about 37 when polar aligned. Not sure why it is that far off, but the scope tracks accurately there.

So use your reading from you mount and align to True North with a compass and your should be close.
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#6 drotto25

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Posted 26 January 2022 - 01:51 PM

Yeah, the mount degree is a rough guess. I live also at about 40, just a little over in fact. I have a GEM28 and the degree marker on the side (this one is printed on) says I am at about 37 when polar aligned. Not sure why it is that far off, but the scope tracks accurately there.

So use your reading from you mount and align to True North with a compass and your should be close. Remember Polaris itself is not exactly true north either.

Edited by drotto25, 26 January 2022 - 01:52 PM.

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#7 RogerM

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Posted 26 January 2022 - 02:03 PM

The ASIAir does not have a built in GPS, it gets location coordinates from a mount that has that feature.  As was mentioned previously, there are a variety of apps that can produce your location coordinates, I use SkySafari and there is an internal 'Location' setting that lets you set your position based upon a map. It then gives you the precise Lat/Lon coordinates that you can then plug into the ASIAir.

 

The general Latitude for your area is 37º. Setting your mount' latitude to that and roughly aligning to true north will allow the ASIAir' PA routine to function just fine.  The two opposing screws are used to set the mount' latitude, it takes a little practice to operate both screws (simultaneously) in opposing directions to adjust the mount.

 

As far as your finderscope not "seeing anything", assuming that you did have the main scope pointing within a couple of degrees of Polaris, it very well can be that the finderscope needs to be co-aligned with the main scope.  This can be done during daytime by first centering a distant (couple miles) object and then aligning the finderscope to that same object.


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#8 Oort Cloud

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Posted 26 January 2022 - 02:55 PM

If plate solving is failing, go to preview mode, take a test shot, amd figure out why the AA can't see enough stars to plate solve. Check: focus, lens cap (telescope), exposure, gain. Once you're able to get a test shot that shows nice focused stars, *then* try the PA routine.

FYI, the polarscope also has caps that need to be removed from both ends, has its own focuser (twist the eyepiece to focus), and needs Dec to be rotated 90 degrees so the polarscope can see "through" the Dec axis.

Edit: I should mention that I'm assuming that's an EQ6-r in the picture above, because it looks just like mine.

Edited by Oort Cloud, 26 January 2022 - 05:22 PM.

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#9 tita

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Posted 27 January 2022 - 12:10 AM

What do the stars look like when you use preview without the Bahtinov mask? Are they roughly star looking of are they large round circles? If moving the focus on the Redcat back and forth, it does not bring close to focus, it is possible that the camera is not at the right distance. I struggled with that when I first started out. 

 

For you question about polar alignment using the mount's polar scope, I think Oort Cloud's answer is the solution to your problem. Rotate the axis 90 degrees and look through the scope. You should be able to see something unless you are out of focus. Trying during the daytime first helps. Also, when you turn the power to the mount on, the red light for the polar scope makes things harder for me to see, I prefer to have it off.


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#10 TrickQuestion79

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Posted 27 January 2022 - 12:33 AM

What do the stars look like when you use preview without the Bahtinov mask? Are they roughly star looking of are they large round circles? If moving the focus on the Redcat back and forth, it does not bring close to focus, it is possible that the camera is not at the right distance. I struggled with that when I first started out. 

 

For you question about polar alignment using the mount's polar scope, I think Oort Cloud's answer is the solution to your problem. Rotate the axis 90 degrees and look through the scope. You should be able to see something unless you are out of focus. Trying during the daytime first helps. Also, when you turn the power to the mount on, the red light for the polar scope makes things harder for me to see, I prefer to have it off.

ok. So today was worse than yesterday. Yesterday, I pointed at some stars and could at least see "large round circles" or kind of star looking things. But today, I got a blur; nothing. This is what I got:

IMG 4597
The only difference was that I put in my l-extreme filter in today. 
 
Also, I tried using the polar scope today and saw like a dim light that I am assuming was polaris. It was so so very hard to see and I kept losing it. I checked my focal length, and made sure it was rotated 90 degrees. Also, I still don't get the focusing part yet. Should I do that before polar alignment? Either way, I don't think the image I got from preview with the AIR was because of the focus.
 
Also, do you keep the rig as it is every night and not take it apart? PLUS, anyone have any cable suggestions? My cables are long and get all over the place. 

Edited by TrickQuestion79, 27 January 2022 - 12:34 AM.


#11 Robert M

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Posted 27 January 2022 - 06:04 AM

It appears to me from what you are describing that you aren’t focused.

 

Work on getting focused first then you can more easily polar align.

 

 

Here is my startup checklist so far

1. Setup tripod and point yellow leg north (I’ve got a certain leg on my setup that needs to point north)
2. Carefully level tripod
3. Install mount and check levels
4. Make sure mount is in home position, RA vertical, DEC pointed near Polaris
5. mount telescope setup to mount
6. connect cables to each other and power source
7. Balance RA & DEC axes
8. power up mount, wait 1 minute
9. Verify mount limits
10. power up ASIAir Pro
11. Connect iPad to wifi and connect to ASIAir Pro
12. program/check plan
13. check focus with R filter
14. align mount (software) to Polaris with ASIAir Pro
15. use asi ipad software to align to target
16. double check focus
17. take a couple test frames to check framing
18. program in filter sequence and imaging sequence
19. take light frames (pictures of the actual target)

 

I still need to develop a routine for flats and darks.


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#12 Oort Cloud

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Posted 27 January 2022 - 06:32 AM

For you question about polar alignment using the mount's polar scope, I think Oort Cloud's answer is the solution to your problem. Rotate the axis 90 degrees and look through the scope. You should be able to see something unless you are out of focus. Trying during the daytime first helps. Also, when you turn the power to the mount on, the red light for the polar scope makes things harder for me to see, I prefer to have it off.


Just to be clear to OP, I am referring specifically to the Dec axis. So the scope would still be at the highest point on the mount, but instead of being pointed toward polaris, the scope would be pointed east or west. There is a hole in the Dec axis that the polar scope looks through. If the Dec is in the home position, the hole will be sideways and the polarscope's view will be blocked.

I think the polarscope illumination works as intended; when at the correct brightness for your light pollution levels, it drowns out all but the brightest stars, making it easier to identify which one is Polaris. If you live in heavy light pollution, the other stars may already be drowned out by the LP, in which case little to no illumination makes more sense.
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#13 Oort Cloud

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Posted 27 January 2022 - 06:43 AM


ok. So today was worse than yesterday. Yesterday, I pointed at some stars and could at least see "large round circles" or kind of star looking things. But today, I got a blur; nothing. This is what I got:

The only difference was that I put in my l-extreme filter in today.

Also, I tried using the polar scope today and saw like a dim light that I am assuming was polaris. It was so so very hard to see and I kept losing it. I checked my focal length, and made sure it was rotated 90 degrees. Also, I still don't get the focusing part yet. Should I do that before polar alignment? Either way, I don't think the image I got from preview with the AIR was because of the focus.

Also, do you keep the rig as it is every night and not take it apart? PLUS, anyone have any cable suggestions? My cables are long and get all over the place.


Take out the L-extreme. Learn to crawl before running. ;)

I can see the stars on your preview...they are dim, but they are there. And way out of focus, which would be much easier for you to determine if not using a filter that blocks about 90% of the incoming light.

PA, initial focus, goto/solve/center target - all done with no filter or luminance filter. If you want to shoot with the L-extreme, switching to the filter is the last step before final focus adjustment and opening the shutter to collect your lights. Keep in mind, that final focus adjustment may need some combination of longer exposures, binning (even if not shooting binned, use it for focus to increase SNR), and possibly even higher gain due to how much light the filter blocks. Just remember to set any of these back to where you need them for your lights.

Regarding your question about focusing first: this is absolutely essential. If you are using PA software that is trying to plate solve images, then your camera/scope must be in focus. If you are using a polar scope for PA, then your polarscope must be in focus.
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#14 tita

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Posted 27 January 2022 - 11:09 PM

 

ok. So today was worse than yesterday. Yesterday, I pointed at some stars and could at least see "large round circles" or kind of star looking things. But today, I got a blur; nothing. This is what I got:

 

I think you still have large round circles, just now they are very faint because of the L-extreme. Remove it and find focus first. Did you try aiming at a bright light nearby light like a lamp post? I used that the first few times because I was so far out of focus, I could not see a thing. The starts covered the whole field of view, lol.  I suggest once you find focus, you make a note or take a picture of where your focuser is. It will help setup next time until you gain more experience.

 

One other thing that helped me was someone here on CN said to find focus using an eyepiece first and notice how far your focuser is. Then replace the eyepiece with the camera and slowly move the camera towards the scope. They said the focus for the camera is always closer to the scope than for the eyepiece. I am not sure if that is true for all cases, but it helped me a lot because I did not keep going back and forth.

 

 

 

Also, I tried using the polar scope today and saw like a dim light that I am assuming was polaris. It was so so very hard to see and I kept losing it. I checked my focal length, and made sure it was rotated 90 degrees. Also, I still don't get the focusing part yet. Should I do that before polar alignment? Either way, I don't think the image I got from preview with the AIR was because of the focus.

 
Also, do you keep the rig as it is every night and not take it apart? PLUS, anyone have any cable suggestions? My cables are long and get all over the place. 

 

Are you trying to do this on the ASIair pro or on the polar scope in the EQ6R? The polar scope in the mount is independent of the scope focal length, only ASIair pro cares about that. But ASIair does not need you to rotate 90 degrees, at least for me it asks to turn 60 degrees? I will just assume you are talking about ASIair. In that case you don't need to see Polaris on the screen. Just anywhere near North is close enough. If ASIair can plate solve, you can continue with the PA routine.

 

If you mean the polar scope inside the EQ6R, it has a focuser that you can turn. It should be the piece closest to your eye. Yes, I agree with you that Polaris looks faint when you look through it. But it looks bigger than the other stars in the area. If you use the EQ6R polar scope you have to make sure your mount is pointing close enough to the north pole (I just use a compass on my phone) so Polaris will be visible when you look through it. 

 

With ASIair, you do not need to polar align the mount with the polar scope. It is literally a pain in the neck. ASIair is more forgiving where you aim your scope.

 

I do not leave my rig setup overnight with a couple of exceptions. I know some folks do and have nice covers to protect it from the elements. Btw, I read here on CN that you should not store your EQ6R with the clutches engaged. 


Edited by tita, 27 January 2022 - 11:11 PM.

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#15 TrickQuestion79

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Posted 10 February 2022 - 07:33 PM

So, I went back and tried to focus with the asiair. I haven't gotten a chance to try focusing during the day, but I'll definitely  try that when I get the chance. Here's some pics:

1
Album: ASIAIR focusing
10 images
0 comments

 

I tried with and without the bahtinov mask. I tried changing the focus on the redcat, but ultimately, leaving it at the farthest back seemed like the best choice. So I'm a little confused as to why or if I'm maybe doing something wrong. I think a couple of the pics were from "focus" and most of them were from the preview menu for the asiair.

 

For a few of the pictures, you could see the bahtinov mask, I was wondering why that was and if that was supposed to be like that. I also was wondering: What exactly does a focused preview look like on the AsiAir? Anyone have any pics or know where to find pics of a successful focus?
 

Lastly, what exactly would a zwo eaf be useful for?


Edited by TrickQuestion79, 10 February 2022 - 07:34 PM.



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