Sharpcap Polar alignment

gregbradley · #1 21-02-2021, 12:58 PM

I tried it out for the first time last night. Very clever software.

It worked well. I need to read the manual to know exactly what is meant by left and right but apart from that it went smoothly.

It does seem a little slow to update with changes though. About 1min to 1:30 to update but I figure that may be the largish files from my QHY600 although I was using 3x3 binning so that would be about 10mb images.

Any advice there?

Do you do more than one iteration? I got it to where it said good polar align and fairly small error. I thought a 2nd run might fine tune it more or is it a waste of time?

Greg.

AstroJunk (Jonathan) · #2 21-02-2021, 01:36 PM

Max gain, min appropriate shutter speed and 8 bit if needed. You could easily afford to use ROI too with a full frame sensor to speed up transfer if that's an issue.

You should be able to get an almost live view which makes alignment outstandingly quick and easy.

Oh, and don't forget to remove any narrowband filters

AnakChan (Sean) · #3 21-02-2021, 02:19 PM

Greg, if you're using your main camera, what focal length is your scope? My knowledge may be legacy but I believe SharpCap PA has a preference for a certain FoV.

Nikolas (Nik) · #4 21-02-2021, 03:38 PM

I already have a polemaster camera, I've use both the polemaster software and sharpcap software (which recognises the camera) Both do a great job getting polar alignment right.
If anything sharpcap may be a touch more spot on but not much in it at all.

glend (Glen) · #5 21-02-2021, 05:42 PM

I always use the main imaging camera for polar alignment, would never rely on Polemaster. A Polemaster camera only looks from the mount perspective, and the scope view can be a little different. Think cone error, etc. A scope view and alignment is preferable and will likely give you more precise goto. Plus you can forget about buying Postmaster, obsolete anyway.

Nikolas (Nik) · #6 21-02-2021, 06:58 PM

Quote:

Originally Posted by glend

I always use the main imaging camera for polar alignment, would never rely on Polemaster. A Polemaster camera only looks from the mount perspective, and the scope view can be a little different. Think cone error, etc. A scope view and alignment is preferable and will likely give you more precise goto. Plus you can forget about buying Postmaster, obsolete anyway.

Wouldnt the scope perspective depend on the type of scope?
I have had 10 minute unguided images on my scopes because of the polemaster PA accuracy. both on my 130 APO and 72 ed refractor.
I have a belt modded eq6 mount.

xa-coupe (Jeff) · #7 21-02-2021, 07:43 PM

Stand behind the mount and the knob on your left gets turned in for 'left' adjustment and obviously the right knob for right. Once I worked that little gem out it was easy.

jahnpahwa (JP) · #8 21-02-2021, 08:12 PM

That's ages for an update... Is it failing to solve other frames in between those updates (updates of error, I assume)? It should list the number of discarded frames if there are any. My frames from 1600mm come through within a second, and loop every 2 or 3 seconds without an issue, binned 1x1 as far as I know.

In terms of iterations, I do it once, but get it to "Excellent", which is usually hit when below +/- 20" on both RA and dec.

I absolutely love sharpcap, am happy I found it before i started to read seriously about polemaster.

Nikolas (Nik) · #9 21-02-2021, 10:59 PM

Quote:

Originally Posted by jahnpahwa

That's ages for an update... Is it failing to solve other frames in between those updates (updates of error, I assume)? It should list the number of discarded frames if there are any. My frames from 1600mm come through within a second, and loop every 2 or 3 seconds without an issue, binned 1x1 as far as I know.

In terms of iterations, I do it once, but get it to "Excellent", which is usually hit when below +/- 20" on both RA and dec.

I absolutely love sharpcap, am happy I found it before i started to read seriously about polemaster.

If sharpcap works perfectly don't buy the polemaster no need.

gregbradley · #10 21-02-2021, 11:31 PM

Quote:

Originally Posted by xa-coupe

Stand behind the mount and the knob on your left gets turned in for 'left' adjustment and obviously the right knob for right. Once I worked that little gem out it was easy.

Ah yes. Thanks for that.
Most valuable.
Greg

gregbradley · #11 24-02-2021, 12:03 PM

Just a quick note to say after using the Sharp Cap polar alignment tool just once the results were terrific and I got round stars again.

TPoint has been the high standard for me in the past. I am not sure why its suddenly not giving accurate polar alignments like it has. I didn't change anything.

Oddly TPoint seemed to work same as always at home on my PME mount.
Its not playing well currently with the AP1600 mount.

Strange hobby this. I look forward to a long stretch of everything working like it should.

5 clear nights got reduced to 2 1/2 partial nights of imaging due to issues of one kind and another. Most of which were conquered but it cost time.

Greg.

tim.anderson (Tim Anderson) · #12 24-02-2021, 12:59 PM

Quote:

Originally Posted by xa-coupe

Stand behind the mount and the knob on your left gets turned in for 'left' adjustment and obviously the right knob for right. Once I worked that little gem out it was easy.

This is true if the post that the bolts work on is on the "far" side of the mount. If the post is on the "near" side (as it is in my case), screwing the left bolt moves the mount head to the right.

xa-coupe (Jeff) · #13 24-02-2021, 01:13 PM

Quote:

Originally Posted by tim.anderson

This is true if the post that the bolts work on is on the "far" side of the mount. If the post is on the "near" side (as it is in my case), screwing the left bolt moves the mount head to the right.

Hence stating that you need to be behind the mount for this to be true... standing in front of it will reverse it obviously, but for us simple folk, twist the left button to adjust the 'left' reading in SharpCap works okay.

JA · #14 24-02-2021, 03:01 PM

This Gal (Amy) presents it well .....

Best
JA

Click here to load the video

gregbradley · #15 24-02-2021, 08:18 PM

It was a little bit confusing when I first tried to implement the left/right adjustments but not too hard.

If you adjust it the wrong way the error increases so you know to go the other way.

Greg.

tim.anderson (Tim Anderson) · #16 25-02-2021, 10:00 AM

Quote:

Originally Posted by xa-coupe

Hence stating that you need to be behind the mount for this to be true... standing in front of it will reverse it obviously, but for us simple folk, twist the left button to adjust the 'left' reading in SharpCap works okay.

No. It actually does depend on the position of the post inside the mount head. Assuming you are set up facing south, an EQ8 mount has the post and bolts on the "north" side of the mount. On the other hand, the NEQ6 has the post on the "south" side. Hence the motion is opposite for the two mounts.

Wilsil (Wilco) · #17 25-02-2021, 02:12 PM

I think that you can change the up/down notification f it is the wrong way. I have to go up with my mount if Sharpcap tells me down and the other way.
Also left and right is looking front on, not from behind the mount.

N1 (Mirko) · #18 25-02-2021, 08:40 PM

Interesting stuff, and I'm gonna give this a go myself. But that left-right business is confusing me. I would interpret right to be clockwise and left a CCW rotation of the mount head in azimuth, but that would mean it's irrelevant which way you face when looking at the mount, assuming you're not standing on your head or something. What am I missing?

Wilsil (Wilco) · #19 26-02-2021, 01:11 PM

If you don't know which is which, try one side.
If the error is getting bigger, it was the other side.
When SharpCap tells me left, I turn the left bolt when you look at it from the front. Why? Because when I did the other one, the error was getting bigger.

gregbradley · #20 26-02-2021, 01:28 PM

Quote:

Originally Posted by Wilsil

If you don't know which is which, try one side.
If the error is getting bigger, it was the other side.
When SharpCap tells me left, I turn the left bolt when you look at it from the front. Why? Because when I did the other one, the error was getting bigger.

Yeah, that's what I did also. A bit clumsy as an instruction as left and right is a meaningless statement without a prior orientation from what viewpoint?

Greg.