SharpCap Forums

Robin,
I updated astap to newest version and tried for Polaris again. The same issue as before. If astap search center starts near object no problem. Whole sky search takes way to long. I did find something to get more stars is to switch from raw16 to mono8 seems to help. I find using astap works well if you center search starting at object and point scope to general area.
What would be great is to have a select switch in push to window to change from whole sky solver (ansvr) and close in solver( astap).

George

Hi George,

yes, the idea of a plate solver selection in the PushTo window would be good. I do have some other ideas in respect to plate solving, but they aren't ready to preview just yet.

cheers,

Robin

Hi robin,

There is some issue with astap interface with sc. last night the orange bar showing solve fail would come up. Then immediately a bar would come up solve successful. I know it’s part of astap causing the lack of stars sensed. I would use ansvr and get over 600 stars then switch to astap same camera settings and get maybe 20 stars. Honestly I’ve been usinh ansvr more and more because it works although slower. Still faster than chasing objects down with charts and finder
George

Hi George,

under some circumstances, SharpCap runs Astap twice - the first time with settings that say 'use the last successful field of view' and the second time requesting that Astap scans all different fields of view. However, I don't think you should get an orange failed notification if the first attempt fails, it just accepts that the 'fast' option didn't work and runs on to the slow option.

I will have to dig through logs to get to the bottom of this - if you have time to find any from the affected session and send them to me then please do.

cheers,

Robin

Robin,

Astap is still not working consistently and I have tried every setting I can find. The issue is to few stars. I know this is not sc but astap. Using the same frames with ansvr and astap, ansvr will catch at least 8 times more stars. I have actually been adjusting the setting in plate solving higher to limit stars to increase solve speed. Is there any way to auto limit stars to make up for star density (ie: Milky Way)?
The push to is working so well I took finder off scope.

Great job!!

Newbie here...

Quick question: It would be very helpful if PushTo could be to a specified static Alt/Az via plate solving instead of to a target RA and DEC. Could that be implemented?

Long explanation: I'm an asteroid occultation observer, and for us, an observing run consists of pointing at a star that will be occulted and recording a couple of minutes of video centered on the event time. Mostly, we set up the same as anyone and are there to run the telescope, which is tracking, and PushTo as it is will help with that. Sometimes, however, we "prepoint" the telescope to the location in the sky where the target star will be at the time of the event and just lock it down. A laptop or other recording device is then configured to record a sequence centered on the event time. The computer is recording as the target star drifts into the field, and if we've done everything right, the occultation occurs as the star is near the center of the FOV.

Sometimes that's to be able to sleep, but sometimes we want to get multiple "chords" on an event and will prepoint a telescope, set up to record, then drive to some other location, prepoint another telescope, etc. until we run out of time or telescopes. Naturally the more quickly we can get the telescope onto the target location (not the target itself), the better. Currently most of us are star hopping using charts we prepare with time offsets, which is very clumsy given what can be done with plate solving. The PushTo function as it exists would help, but being able to PushTo a static location in the sky would be a great help to us. Given that we're leaving telescopes unattended, these tend to be smaller scopes, often on purpose-built mounts that are made to be inconspicuous and somewhat resistant to wind shake, and are often not all that easy to point. In addition, the fact that the static Alt/Az, despite it being stationary relative to the telescope, is a moving target relative to the stars, so it can be a frustrating task.

Traditionally, occultation recordings have been made using analog video. Recently, however, several of us are transitioning to using planetary cameras and SC is working very well for that. Having PushTo will be great for finding target stars, and if it could be tweaked to help us prepoint telescopes too, it would really help.

Thanks,
Bob

Hi Bob,

thanks for the suggestion and for the clear explanation of why you approach things that way. I think it should be possible, although the code is set up at the moment to aim for an RA/Dec co-ordinate, I could re-calculate that each frame from the target alt/az.

A couple of things come to mind though...

1) The location would need to be precise for the Alt-Az => RA/Dec calculation to be correct, also the time. Errors in either are unimportant when chasing an RA/Dec co-ordinate, but a problem when heading to an Alt/Az.
2) Refraction will need thinking about - it needs to be consistent between your calculation of the target alt/az and SharpCap's calculations of AltAz from RA/Dec

Right now you might be able to get something workable by the following

* Set up the ASCOM simulator mount with the correct location info
* Connect to it in SharpCap
* Start the PushTo assistant and enter an RA/Dec that is close to the Alt/Az you want
* Tick the box for 'update mount position with plate solve results'
* Initially use PushTo normally to get to your target RA/Dec - the code will update the mount position each time it solves, which will show in the right hand panel in the 'Scope Controls' section. That section will *also* show the Alt/Az as calculated by the ASCOM telescope simulator.
* Once close, switch from using the guidance in the push-to window to adjusting based on the Alt/Az readout on the right.

It would be interesting to know if that approach works, as what I would write in code would be very similar to it, just with the target RA/Dec in the push to assistant being updated each frame from the target Alt/Az

cheers,

Robin

Gfischer wrote: Fri Oct 27, 2023 9:41 pm Robin,

Astap is still not working consistently and I have tried every setting I can find. The issue is to few stars. I know this is not sc but astap. Using the same frames with ansvr and astap, ansvr will catch at least 8 times more stars. I have actually been adjusting the setting in plate solving higher to limit stars to increase solve speed. Is there any way to auto limit stars to make up for star density (ie: Milky Way)?
The push to is working so well I took finder off scope.

Great job!!

Hi George,

please could you try 'SharpSolve' when you have a chance - that's the new internal plate solving engine built into the very latest version of SharpCap.

viewtopic.php?t=7122

As long as your field of view is about 0.5 degrees in each direction and you can see plenty of stars in a stretched image (ideally 60 or more) then it should work. If you find it doesn't work then please send me some frames and I will see if I can improve it

cheers,

Robin

Hi Robin,

Thanks for the suggestion, which may work well enough. The telescopes we use for prepointed recordings tend to have fairly short focal ratios, so small differences between the desired alt-az position and entered RA & Dec may not be large enough to make a lot of difference if it doesn't take too long to get dialed in to the desired location. In any case, PushTo as it currently stands will be a big help.

Thanks for considering it.
Bob

Robin,
I downloaded the new SC with the internal plate solve. I noticed immediately when viewing live view the frame shown seemed to lag behind. I would move focus on a 2 sec frame and not see the change for several frames. This did not happen with previous version. Also when using the lightning stretch tool the top and bottom of frames were almost white. I changed global setting for stretch to bottom with no effect.
I used the push to tool with internal solve and the solver worked most of the time. One thing I noted is when you get close to object solver would no longer read small scope movements. I think this might be due to my 30min by 20min fov. Sometimes the solver would not solve at all I recorded log and copied into word document. Solve does not like globular m15 seemed to stop solver.
Twice SC completely froze and I could pull up other programs and they were fine. To get out of SC i had to use task manager to close. My older laptop could be part of problem. I added my computer and equipment at end of log file. Hope this helps.

George