Plate Solving with mount

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pintsizedlala
Posts: 3
Joined: Sat Mar 13, 2021 9:19 pm

Plate Solving with mount

#1

Post by pintsizedlala »

Good morning everyone

I am just in the process of removing the hand controller from my mount and using my PC to drive the mount

I have a Skywatcher EQ35-M mount and am using a William Optics 50mm guidescope and ZWO ASI 120mm MINI camera

I have got all of the ASCOM drivers installed and working correctly. I have installed Stellerium and connected the mount to that.

Once polar aligned I can select a star in Stellerium and the mount will goto that location reasonably accurately. I have also got the mount talking to SharpCap and have All Sky Plate Solver installed. I can choose Plate solve from the tools menu and with 10 seconds it has correctly plate solved the current view.

I then hit the 'Find my location' button in the telescope control and it plate solves, syncs the mount and readjusts the view. However - it manages to align the star in the center horizontally but the start always ends up 1/3 from the bottom of the view.

I am assuming I have done something wrong somewhere but I am not sure where and I cannot find anyone else that has had the same issue. Was I supposed to align the star center of the view prior to hitting 'Find my location'?

It isn't a major as it finds the location but it would be nice if it centrally aligns in both direction (or perhaps it is not meant to)

Any help is greatly appreciated

Thanks

Eric
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Re: Plate Solving with mount

#2

Post by admin »

Hi Eric,

I think it is probably caused by some confusion between the various pieces of software as to whether the mount is using JNOW or J2000 co-ordinates (ie whether the co-ordinates are those for the star *today* or it's RA/Dec back in 2000). The best advice is to set everything up to use JNOW - if SharpCap sees that the mount is reporting that it is using JNOW then SharpCap will automatically convert the plate solving results from J2000 to JNOW - see this thread for more discussion : viewtopic.php?f=38&t=3832&p=20249#p20249

cheers,

Robin
pintsizedlala
Posts: 3
Joined: Sat Mar 13, 2021 9:19 pm

Re: Plate Solving with mount

#3

Post by pintsizedlala »

Hi Robin

Thanks for you help

I have reconfigured EQCOM and Stellerium to use JNOW so will give it a try when we get some clear sky and let you know how we get on

Thanks again

Eric
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Re: Plate Solving with mount

#4

Post by admin »

Hi Eric,

Hope that goes well for you :-)

Based on the fact that I've seen this same question a few times recently I've made a change so that future versions of SharpCap will assume that the mount is working in JNOW co-ordinates unless it specifically reports otherwise (rather than assuming J2000 unless it reports JNOW). I think that will have the effect of making the right choice by default for most people's setup.

Cheers, Robin
pintsizedlala
Posts: 3
Joined: Sat Mar 13, 2021 9:19 pm

Re: Plate Solving with mount

#5

Post by pintsizedlala »

Hi Robin

Thanks for this

I have spent the weekend updating the co-ordinates for all the software we use to J-NOW and had a chance to test this over the weekend and have had near perfect alignment results

Many thanks for all your help

Eric
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Re: Plate Solving with mount

#6

Post by admin »

Hi Eric,

thanks for confirming that the switch to JNOW worked OK.

cheers,

Robin
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