Is anything as good as sharpcap for polar alignment?

Stonius (Markus) · #1 09-06-2021, 06:19 PM

I only use sharpcap for the polar alignment feature (which I like a lot) but I prefer Firecap for planetary stuff.

Sharpcap is more intuitive than my polemaster and it uses the camera you will be imaging with so it's not possible for there to be a misalignment between camera and mount. But it seems to be overkill to pay a license fee each year for polar alignment.

Does anything else do it quite as well? Something you can actually own, rather than license every year?

Cheers

Markus

Nikolas (Nik) · #2 09-06-2021, 07:19 PM

Quote:

Originally Posted by Stonius

Sharpcap is more intuitive than my polemaster and it uses the camera you will be imaging with so it's not possible for there to be a misalignment between camera and mount. But it seems to be overkill to pay a license fee each year for polar alignment.

Does anything else do it quite as well? Something you can actually own, rather than license every year?

Cheers

Markus

Polemaster or the old fashioned drift alignment if you have time, an abacus and culottes

Startrek (Martin) · #3 09-06-2021, 10:03 PM

Skywatcher Synscan polar alignment routine
1/It’s Free
2/ Is a feature of your Syncan handcontroller
3/ Don’t need a view of the SCP, just 2 alignment stars between 30 and 70 degrees altitude and within 30 degrees azimuth from the south meridian
4/ I use BYEOS and my old DSLR for alignment iterations ( usually 2 to 3 iterations only required )
5/ Usually polar aligned under an half an arc minute within 5 mins

Been using this method for over 4 years , just as accurate as pole master

glend (Glen) · #4 09-06-2021, 11:47 PM

What license fee? I have an older version of Sharpcap that has polar alignment and I have never had to pay any sort of annual fee. Of course I have not tried to use if for years, as I have a mount on a pier in my observatory, but the few times I have taken to the dark site on the tripod, Sharpcap PA worked fine.

Most modern mounts have reasonable alignment routines, if you know what your doing enough to find true south so you can get close enough to nudge to alignment stars. My CGX has a wonderful sky modelling tool, that will yield increasing accuracy as you add stars to the model.
Drift alignment is for the obsessives, I have never understood why folks bother.

mswhin63 (Malcolm) · #5 09-06-2021, 11:52 PM

I have used a few, although not the Sharpcap or Firecap, products.

I personally use the Ekos Polar alignment. I don't need to see the pole star location as it can determine polar alignment from outside the pole star location.

The most recent addition is the Yellow (Azumith) Red (Dec) lines make it so easy to tweak the right controls, I usually have it set up on the first go all the time and within 10 minutes. I believe NINA may use the same type of alignment and possibly others. I struggled to use NINA and now I run a Raspberry Pi for portability.

Stonius (Markus) · #6 09-06-2021, 11:57 PM

Quote:

Originally Posted by glend

What license fee? I have an older version of Sharpcap that has polar alignment and I have never had to pay any sort of annual fee.

Maybe that's the trick, (having an old one) but I get a message telling me my license has expired and many menu options are greyed out.

Markus

AdamJL · #7 10-06-2021, 08:25 AM

I looked into it and yeah the idea is subscribing for polar aligning seemed nuts. So I went with PoleMaster. Yeah it’s weird system but I can polar align in under 3 mins now. The longest time is spent rotating the RA axis

N1 (Mirko) · #8 10-06-2021, 08:30 AM

Of course priorities vary, but I thought the PA feature alone was worth the 10 quid per year. A lot of years until that adds up to the cost of one other the other tech based solutions.

RugbyRene (Rene) · #9 10-06-2021, 08:51 AM

KStars has an excellent PA routine built into it's free software. You can align on the SCP or if you can't see the SCP then any other part of the sky.

etill (Elliot) · #10 10-06-2021, 08:52 AM

I use PHD2 to align, takes me a while and can't compare as I've never tried sharpcap but from what I've read it has a similar tool to do it.

I start with polar drift align pointing somewhere in the vicinity of SCP to get close then do proper drift align, 15 minutes for alt then swap and do 15 minutes for az, then swap back and check one more time for each just to make any final adjustments.

Maybe not suitable if you aren't using phd for guiding, and it takes me over an hour. Results seem quite good though.

AdamJL · #11 10-06-2021, 09:37 AM

Quote:

Originally Posted by etill

it takes me over an hour.

That’s an hour you’ve lost that could be spent shooting/viewing

Stonius (Markus) · #12 10-06-2021, 09:50 AM

Quote:

Originally Posted by etill

Maybe not suitable if you aren't using phd for guiding, and it takes me over an hour. Results seem quite good though.

Yeah, that seems like a lot. If I'm trying for arc-second accuracy, it can take me 20 mins with sharpcap because the locking screws introduce a tiny bit of movement, so there's an iterative process there. But at an hour, I'd be looking for alternatives myself.

Best, Markus

Nikolas (Nik) · #13 10-06-2021, 01:04 PM

Quote:

Originally Posted by etill

I use PHD2 to align, takes me a while and can't compare as I've never tried sharpcap but from what I've read it has a similar tool to do it.

I start with polar drift align pointing somewhere in the vicinity of SCP to get close then do proper drift align, 15 minutes for alt then swap and do 15 minutes for az, then swap back and check one more time for each just to make any final adjustments.

Maybe not suitable if you aren't using phd for guiding, and it takes me over an hour. Results seem quite good though.

Do you use an abacus and wear Culottes?

etill (Elliot) · #14 10-06-2021, 03:55 PM

I don't, and it could be the mistake I've been making all along..

Stonius (Markus) · #15 10-06-2021, 04:07 PM

Quote:

Originally Posted by etill

I don't, and it could be the mistake I've been making all along..

Not many people appreciate just how critical it is to the process of polar alignment, that you dress like a pirate.

It's especially important to the RRRRRR-A axis.

Markus

etill (Elliot) · #16 10-06-2021, 04:07 PM

Quote:

Originally Posted by Stonius

Yeah, that seems like a lot. If I'm trying for arc-second accuracy, it can take me 20 mins with sharpcap because the locking screws introduce a tiny bit of movement, so there's an iterative process there. But at an hour, I'd be looking for alternatives myself.

I think it is a bit excessive too, usually do it when I plan to leave the mount out for a few days with a bbq cover on it. After the hour its about as good as its going to get and the trendline in PHD stays flat, the circle around the guide star showing the error is about the size of the star, error is usually single digit arc-seconds.

I think there are other problems to fix with my setup that render that a little bit unnecessary.

I've read recently that less than perfect mounts (like my CGEM) can actually do better with guiding if you leave them out of alignment a little. The polar drift aligment I start with is fairly quick to get within a couple of arc minutes..