SharpCap Forums

Hi all

Sorry if this is covered elsewhere, but couldn't find any entries and the user manual isn't helping me !

I've got Sharpcap pro and ASTAP, plus the H18 data base. I've managed to run a successful plate-solve pointing at a random part of the sky, so ASTAP and Sharpcap are talking to each other. Everything is going through my laptop via ASCOM.

What I don't know how to do, is to get Sharpcap to centre a named target using plate solving. So suppose I'm looking to image a particular object - I tell my mount where to point, and the mount goes and points let's say roughly where it needs to point, but not quite there. How do I then tell Sharpcap the object I want to point to, so it will run a plate solve, work out actually where I am pointed and then move the mount to centre the object ? help please !

Hi

It depends on the mount if the plate solving is done right in 1 or 2 times. With my mount I have to do it twice: 1 time plate solve and then the coordinates are uploaded to the mount and then a 2nd plate solve to match it all and the mount moves to the part that is plate solved. Call it finetuning.
For all this you use the button I circled in the screenshot. If that is greyed out you have to tick the Connected box.

Now in your mount software you give the command to go for example to M31, with a direct command or the coordinates of M31.
The mount moves and indeed it can happen that the object is not in view. Now use that circled button again to plate solve and synchronize. When the plate solve is done, is should slew to the right coordinates and M31 should be in view.
This all should be precise, SharpCap is not GoTo software. So roughly pointing at where M31 should be and then telling SharpCap to get M31 in view will not work That is the job of your mount GoTo software or handcontroller.

Menno

File -> Sharpcap Settings -> platesolving tab, 2nd drop down box - select sync & recentre

Hi all again
So I gave this a try last night. Use my hand controller to tell the mount to point at a named object. The mount slewed to it. I had the Plate Solve settings to "select sync & re-centre". So I did a successful plate solve (well the solve message said "success") but then nothing appeared to change i.e. the mount did not move.
Now I do know I have built a pretty good sky model with my mount and reckon the object was already somewhere in the field of view when I did the solve, but I find it hard to believe it was already dead centre - such that no commands were sent to move the mount at all !!
Thoughts ?

Try this: use your hand controller and slew to a random piece of sky. Important part here that it is not to close to Polaris.
Then in SharpCap do the plate solve and sync twice. First time to tell the mount where it is pointing at, the second time to "fine tune". All this is just a 1 time action set at the start of your session.
Now use the hand controller to go to a selected object. Changes are that it's not in view then but that's normal, it depends on how far away the object is from the random slew you did above. Then in SharpCap do the plate solve and sync. The object should come in view then. If not, do the plate solve and sync again. Depending on the mount, that happens sometimes when the mount has to slew a long way.

And a "just in case" remark: before all this, the time and your coordinates have to be correct in your hand controller and polar alignment has to be done. This is base line for the whole model.

Menno

thanks for your helpful reply Menno, shall try your suggestions..

One rather key thing I forgot to mention in my previous post, was that having slewed to the object of interest and carried out a plate solve, it might be the mount wasn't moved because when I took an exposure, the object was incredibly in the centre of the field !!!

Folks,

Is the following Correct?

- When Plate Solving with SharpCap, target coordinates must be entered in separately from SharpCap. If I enter a target into NINA (M42), which then registers RA and Dec coordinates, SharpCap will pick them up and use them as the desired target.
- If I then plate solve in SharpCap, SharpCap will take an image and compare that image (where the scope is presently pointing) to the desired coordinates.
- SharpCap will not Slew to those coordinates automatically, but rather display a box as per "Menno" below, and the user can click on the indicated button and Sharp Cap will then command the mount to adjust to move to the desired coordinates.

I am aware that NINA has Plate Solving, but need to Plate Solve outside of NINA.

Thanks

Ed

Hi Ed and welcome.

I think that will work.
I do roughly the same with my mount which is a Ioptron CEM mount and has the Ioptron Commander software. In the Commander I can select for example M31 to slew to and the mount slews to it, based upon the sky model in the mount.
I then use SharpCap to plate solve and sync. SharpCap does a plate solve so it knows what part of the sky it's looking at, reads the data from the mount, compares the coordinates and then makes the sync corrections to point to the coordinates the mount wants.

Menno

Menno,
In SharpCap when you plate solve and sync, does that mean that your future go to's will be better synchronized to the catalog objects? My IOptron CEM 25p hand controller has the sync function after I fine tune the object. Is this the same as SharpCap sync?

With your CEM mount can you manually sync in either SharpCap, or in IOptron Commander?

Thanks,
Roger

Hi Roger

I think so. From what I can see on my own CEM25EC, the build in GoTo sky model is more local accurate after a SharpCap plate solve and sync. So I presume that in essence it does the same as the Ioptron sync function.
I myself never used the Ioptron sync anymore after I discovered plate solving
The overall GoTo accuracy is based more upon the way you start: polar alignment and how level your scope is to the sky.

Menno