Maximum Field of View

Using SharpCap's Polar Alignment feature
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LaurieY
Posts: 2
Joined: Wed May 17, 2017 1:50 pm

Maximum Field of View

Post by LaurieY » Wed May 17, 2017 2:19 pm

Hi Robin,
I'm looking forward to being able to try the Polar Alignment when the Astro Gods see fit to show me some stars.
I have seen the question regarding minimum FOV, how about Maximum? I am intending to use a DSLR + lens for imaging and would like to use the same for polar alignment (adding Sparkocam).
If the reasonable upper limit is 2.5 degrees do I need to crop within Sparkocam or Is the upper limit related to arcsec/px rather than the 2.5 degrees FOV? making cropping pointless.
What is the likely arcsec/px limit? My longest lens would give 4 degrees, 2.54"/px
Laurie

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admin
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Re: Maximum Field of View

Post by admin » Wed May 17, 2017 7:04 pm

Hi Laurie,

I think that with a 4 degree FOV you should be OK, as long as your alignment isn't too far off in the first place. The problem is with a wide field-of-view that if a big part of your view is outside the 5 degree circle that SharpCap has star data for then you won't get a solution - basically it will pick the 15 brightest stars in the field, but most of them will be too far from the pole and there will be no match.

cheers,

Robin

SteveInNZ
Posts: 6
Joined: Tue Feb 14, 2017 6:56 pm

Re: Maximum Field of View

Post by SteveInNZ » Wed May 17, 2017 8:38 pm

I use the SharpCap polar alignment function with a Polemaster which has an 11x8 degree field.
Being in the Southern hemisphere, I can't see any stars in the pole region when I'm setting up at home. If the pole is within the field of view, SharpCap usually finds it in a few seconds and shows the target circles. It is so much better than the QHY program which relies on you identifying the stars in the asterism which are sometimes obvious but sometimes they all look the same.

Steve.

LaurieY
Posts: 2
Joined: Wed May 17, 2017 1:50 pm

Re: Maximum Field of View

Post by LaurieY » Wed May 17, 2017 9:35 pm

Steve,
That's excellent news, that gives me plenty to work on. I had thought about a Polemaster because of the way it's mounted, my wallet wasn't so sure.
All I need now is half an hour to capture some images.
I want to be able to align using a DSLR on an Astrotrac without having to add a Guidescope hence my concern over FOV.
Laurie

iwardlaw
Posts: 10
Joined: Fri Apr 28, 2017 1:50 pm

Re: Maximum Field of View

Post by iwardlaw » Wed Jun 28, 2017 2:55 pm

How do you connect the Polemaster to SharpCap, it is not in my camera list.
Ian

iwardlaw
Posts: 10
Joined: Fri Apr 28, 2017 1:50 pm

Re: Maximum Field of View

Post by iwardlaw » Wed Jun 28, 2017 3:19 pm

Reinstalled Polemaster Driver, now in camera list.

Ian

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