Polaris set up

[shropshire lad]

Probably a daft question ... I have Polaris View on my phone and am unsure about how to read what it is telling me ... 

It states "View as in Polar Finder scope" so is this upside down to me eyes view or does a Finder scope show it the correct way up??

Thanks in Advance.

 

[barbulo]

Just match the position of Polaris in the polar scope as shown in the APP. 

[ONIKKINEN]

The app means your polar scope, not the actual finder scope attached to your telescope. You need to polar align so that polaris is in the same position as the app shows. To do this you might need to first rotate your RA axis so that 6 points down and 12 points up as many polar scopes are not that well aligned.

Basically just try to adjust the alt/az knobs until you see the exact same thing as the app shows.

[shropshire lad]

Sorry I need to explain a little futher.

I dont have a polar scope, just a Dslr and lens.

This is the view from the App, stating View as in Polar finder scope. .. 

So is this the way I would position it in my camera (live screen) or is this the inverted view.

TIA

 

Edited September 9, 2021 by shropshire lad

[ONIKKINEN]

You will need a mount that has a polar scope fitted in it to use this method of polar aligning. This view doesn't really translate at all into a camera view inverted or not.

What is the camera and lens mounted on?

[Jiggy 67]

You can’t polar align using the view through the telescope, eyepiece or camera, not using your app anyway, but there are other methods.

If you’re using an equatorial mount, it’s the RA axis that you are aligning with the North Celestial Pole, in which case, the app requires a polar scope 

[shropshire lad]

2 hours ago, ONIKKINEN said:

You will need a mount that has a polar scope fitted in it to use this method of polar aligning. This view doesn't really translate at all into a camera view inverted or not.

What is the camera and lens mounted on?

Skywatcher AZ-GTi and wedge ..... running SynScan Pro to guide it.

Now this is what I was thinking, may be wrong ?!.

Put Polaris in centre of live view, then using the PolarisView position in above App image as an example .... adjust the mount so that the star would move left and down a touch ( approx the diam of the full moon) and the true celestial pole would now be in the centre where my imaginary red cross would be.

[ONIKKINEN]

11 minutes ago, shropshire lad said:

Skywatcher AZ-GTi and wedge ..... running SynScan Pro to guide it.

Now this is what I was thinking, may be wrong ?!.

Put Polaris in centre of live view, then using the PolarisView position in above App image as an example .... adjust the mount so that the star would move left and down a touch ( approx the diam of the full moon) and the true celestial pole would now be in the centre where my imaginary red cross would be.

Technically yes, but in reality would not be very accurate. You will have significant cone error (camera not perfectly in line with RA-axis) in pretty much every setup. There is no easy way to polar align without either a polarscope or the use of polar alignment software like Sharpcap pro. Sharpcap pro and others need a dedicated astro cam to work though, don't know what camera you're working with.

 

You can try to put Polaris in the position as noted in the app, but you will have no real way to tell how far it is in your camera screen, or if its supposed to be inverted or not (you need to experiment on this). Polar scopes work well because every polarscope has etched lines in the eyepiece to show where the circle of Polaris's travel is, which looks exactly like the polar alignment app you use.

 

I also found this: https://www.cloudynights.com/articles/cat/articles/darv-drift-alignment-by-robert-vice-r2760. This method looks time consuming and annoying but should work if you spend some time on this.

[shropshire lad]

8 hours ago, ONIKKINEN said:

Technically yes, but in reality would not be very accurate. You will have significant cone error (camera not perfectly in line with RA-axis) in pretty much every setup. There is no easy way to polar align without either a polarscope or the use of polar alignment software like Sharpcap pro. Sharpcap pro and others need a dedicated astro cam to work though, don't know what camera you're working with.

 

You can try to put Polaris in the position as noted in the app, but you will have no real way to tell how far it is in your camera screen, or if its supposed to be inverted or not (you need to experiment on this). Polar scopes work well because every polarscope has etched lines in the eyepiece to show where the circle of Polaris's travel is, which looks exactly like the polar alignment app you use.

 

I also found this: https://www.cloudynights.com/articles/cat/articles/darv-drift-alignment-by-robert-vice-r2760. This method looks time consuming and annoying but should work if you spend some time on this.

Thank you for the reply, I will take a look at that link.

 

[StevieDvd]

Do you connect your setup to a PC for image capture?

If so it's possible to use a small guide cam/finderscope and use Sharpcap PA, not sure how small a finderscope has been used sucessfully but Sharpcap mention a 200mm one with a couple of cheap guide cams that will work.

 

[higgins]

Try drift alignment.  If you Google DARV (Drift Alignment  by Robert Vice) that should get you polar aligned as accurate as any method, better than polaris view.  Edit -just noticed its been mentioned. 

Edited September 10, 2021 by higgins

[AstroMuni]

On 10/09/2021 at 11:15, StevieDvd said:

If so it's possible to use a small guide cam/finderscope and use Sharpcap PA, not sure how small a finderscope has been used sucessfully but Sharpcap mention a 200mm one with a couple of cheap guide cams that will work.

Thats a good suggestion. BTW, you dont need a guide scope. This can be done with the main scope itself.

Edited September 14, 2021 by AstroMuni

[shropshire lad]

25 minutes ago, AstroMuni said:

Thats a good suggestion. BTW, you dont need a guide scope. This can be done with the main scope itself.

But I don't have a scope, just a Dslr and 500mm lens.

 

[AstroMuni]

1 hour ago, shropshire lad said:

But I don't have a scope, just a Dslr and 500mm lens.

As long as the DSLR is mounted on an equatorial mount, it would still work. The pre-reqs are EQ mount, camera and control through a PC (to allow it to platesolve etc). I use ekos that can control the mount & camera and its Polar alignment tool is described quite well in this page https://www.stellarmate.com/support/ekos/align.html

In a nutshell it asks you to point near the pole, takes an image and platesolves. It then asks you to rotate the mount and takes another image. It does this twice so captures 3 images. Using these it knows how far your mount axis is away from the true north. Then there is a helpful screen which guides you to align the mount.

Sharpcap uses a similar process.

Edited September 14, 2021 by AstroMuni

[shropshire lad]

Thank you AstroMuni I will give that link a look.

 

[StevieDvd]

3 hours ago, AstroMuni said:

Thats a good suggestion. BTW, you dont need a guide scope. This can be done with the main scope itself.

Given the original posters equipment I thought a small scope would allow PA using Sharpcap in live mode, you can do a PA using a DSLR but I believe that entails saving the images as a workaround. Not surprising as it uses some of the concepts from Themos PPA app from a few years back, Polemaster & Sharpcap PA followed a little later.

It would be nice to see a small PA camera that fits on a DSLR hotshoe.

[900SL]

I can use ASIairpro with my imaging camera (Nikon) for PA. Cone error is taken into account in the 60 degree rotation between plate solves as I understand it. It is also quite forgiving of initial alignment.. I was 10 degrees out the other evening on azimuth and it still worked