Plate Solving Issues

[Bob_the_Science_Guy]

Hey Guys, 

I run a Youtube Channel and as part of that I like to live stream the telescope.  But the problem is lack of consistency.

Equipment:

Orion EON 110, Meade 10" SCT

Orion Mount - Exos2-PMC. Meade Mount 'push to' alt az with clockwork drive

APT, SharpCap, PHD2, Stellarium, ASCOM Hub

Focal Lengths Orion 660mm, Guide Scopes 188mm, SCT 2500mm

Powered USB for ZWO cameras (120 and 294)

 

Here is what happens:

Cameras, sometimes work, sometimes don't.  I am not making the mistake of trying to get APT and SharpCap to view the same camera.  I used APT for the guide scope and SharpCap for the main tube and the 294.  Sometimes APT will take an image, sometimes it will do live view, sometimes both, sometimes neither.  It is very distracting to the stream to spend an HOUR turning the computer off and on, plugging, unplugging and replugging the cameras just to get them to image.

When I do get an image it plate solves at the NCP, but if you move away, setting the coordinates to the scope position or the object I am looking at, it doesn't consistently plate solve.  Sometimes it does, sometimes not.  It is completely irregular and can change within a session.

Not all three plate solving means even work, for blind solve, 

ASTAP never seems to work, either in point craft or locally stand alone

PS2 and ASPS work intermittently, as above

I did download all the catalogs and they are in the default directories.

This is very frustrating and I was wondering if anyone else is having this issue or has suggestions.

Bob

[Bob_the_Science_Guy]

As a side note, SharpCap does a great job with polar align, but will not plate solve at all.  Am I missing a setting?

Bob

[bottletopburly]

What iso are you using for blind solving, using APT i find iso 1600 works well with a  6 sec exposure and use the ASTAP option usually blindsolving in about 4 sec and have the G18 star catalogue installed , I would ask @han59 for help with Astap settings I’m sure there’s a setting that needs tweaking  I use a 350 and a 1000 mm fl scopes .

 

 

Edited November 13, 2020 by bottletopburly

[symmetal]

You shouldn't plate solve at the NCP especially if your platesolving is syncing the telescope position, as a minor error in RA positioning may generate a very large RA error when syncing, as at the NCP any RA position is actually correct, and one half of the image is effectively rotated 180 degrees compared to the other half, so establishing image rotation is more a matter of opinion rather than a useable value. 🙂

Alan 

[han59]

1 hour ago, Bob_the_Science_Guy said:

Not all three plate solving means even work, for blind solve, 

ASTAP never seems to work, either in point craft or locally stand alone

Provides us with a test image for further investigation. E.g. upload it to nova.astrometry.net and give the link.

 

- You should see 30 or more stars on the image.  Longer exposure time helps. With a F/5 system a few seconds is enough but for long focal lengths maybe up to 30 seconds is required.

- Don't bin too much. Keep dimensions equal or above 1280x960 pixels.

 

Han

[Jm1973]

2 hours ago, Bob_the_Science_Guy said:

As a side note, SharpCap does a great job with polar align, but will not plate solve at all.  Am I missing a setting?

Bob

I think the default will only platesolve within 15 degrees. 

[Bob_the_Science_Guy]

1 hour ago, symmetal said:

You shouldn't plate solve at the NCP especially if your platesolving is syncing the telescope position, as a minor error in RA positioning may generate a very large RA error when syncing, as at the NCP any RA position is actually correct, and one half of the image is effectively rotated 180 degrees compared to the other half, so establishing image rotation is more a matter of opinion rather than a useable value. 🙂

Alan 

I've heard that, but the problem is last night that was the ONLY location that would plate solve.  I tried M31 and a number of other areas first after polar alignment.

Just irritating when things don't work, I'm trying to figure out if I did anything to change it, but it goes back and forth in the same session without any changes.  I've moved all the plate solving software to its own folder in the C drive, I'll see if that helps as I've seen some folks report problems having it in the 'windows' folder.

 

Bob

[Bob_the_Science_Guy]

Just to make it more interesting.  Sometimes when both Live and Image are working, it won't solve with a single image but WILL solve with live.  Go figure.

Bob

[Bob_the_Science_Guy]

2 hours ago, bottletopburly said:

What iso are you using for blind solving, using APT i find iso 1600 works well with a  6 sec exposure and use the ASTAP option usually blindsolving in about 4 sec and have the G18 star catalogue installed , I would ask @han59 for help with Astap settings I’m sure there’s a setting that needs tweaking  I use a 350 and a 1000 mm fl scopes .

 

 

I don't use an iso, that only comes into play with the Canon.  I'm using ZWO 120 and 294, the 120 is on the guide scope.  I use 50% gain and 4 second exposures with stretch.

Bob

[bottletopburly]

3 hours ago, Bob_the_Science_Guy said:

I used APT for the guide scope and SharpCap for the main tube and the 294. 

Shouldn’t you be platesolving off the imaging camera, why would you need to pltesolve off the guide scope I only platesolve off guidescope when used with polar aligning using sharpcap pro 

[Bob_the_Science_Guy]

2 hours ago, bottletopburly said:

Shouldn’t you be platesolving off the imaging camera, why would you need to pltesolve off the guide scope I only platesolve off guidescope when used with polar aligning using sharpcap pro 

My guide scope and main tube are aligned, so it is a matter of preference.  Using the guide scope works just fine when platesolving is working.  Center the target in the guide scope and it is in view of the main scope.

Bob