SharpCap Forums

I'm sure it isn't a 'bug' but it is an issue that cropped up during last nights imaging session.

My scope is a 115mm f/7 APO, and the camera 294c.

When I used Plate Solve before, it worked fine, but I have now added a 0.8x reducer, taking the down from f/7 805mm to f/5.6 640mm.

Now when I now run Plate Solve, it fails, reporting too many stars. If I reduce the exposure, thus reducing number of stars in the image, it fails again,and reports too few stars.

If I run Plate Solve in Astroart 8, it runs fine. AA8 used its own star catalogue, not All Sky Plate Solver, as in Sharpcap.

Hi,

which tool are you using for plate solving? Astap or Astrotortilla? If Astrotortilla, try increasing the 'sigma' option in the plate solving settings.

Also check to see if you have entered a focal length in the plate solving settings - either directly or via ASCOM. If you have, then you need to update it to take account of the 0.8x reducer.

cheers,

Robin

Hi Robin

Not sure about which 'tool', Astap or Astrotortlla, but it will be whatever came with All Sky Plate Solver, and or Sharpcap Pro.

The change in Focal Length, I did not enter, nor think about. A silly mistake, but blame that on a "senior moment"

When the sky next allows it, I will make that change.

Many thanks

Dave

Hi again Robin

All sorted. It was that I hadn't changed the Focal Length after including the 0.8x reducer in the 'line up'

It is the Atrotortilla 'tool' that I am using.

Many thanks for your help.

Dave

Hi Dave,

glad to hear that the focal length change sorted it.

Astrotortilla, All Sky Plate Solver and AnSvr are all basically the same plate solving program with different installer tools and different user interface - I tend to use the names a bit interchangeably.

cheers,

Robin

I am having a bug issue. I updated to sharpcap 4.0 and platesolve fails for all cameras now, it does not work with the guide, an asi 174 on a 50mm orion guidescope, nor on my 1000mm newt-mak. If i switch to sharpcap 3.2 it works in about 1/2 second, no problem.
so I don't think it is focal legnth or anything like that

Hi,

best thing to do is to look at the SharpCap log - that includes the exact command sent to the plate solving engine, which is maybe different from 3.2 to 4.0, so you could check both logs. For instance in 4.0 using Astap you might see

Info 14:11:38.976949 #1 Running external command : c:\Program Files\Astap\Astap.exe -f "C:\Users\robin\AppData\Local\Temp\d73efd2c-fcbf-414d-a94c-53cb42dbc050\frame.png" -ra 0.000 -spd 90.000 -r 180.000 -z 0 -log

You will also see the diagnostic output of the plate solving engine in the SharpCap log, which might suggest what is going on. If not, feel free to post the log here for me to check.

thanks,

Robin

for whatever reason in sharpcap 3.2 i do not need to put in the focal length of the scope. In 4.0 once i did update that length, it platesolved quickly. I am going to look at the settings from 3.2. I just assumed it imported all the settings when you update it

It turns out 3.2 did not have anywhere to enter that data. here are screen shots of the 2 version.

Hi,

the settings from 3.2 are pulled into SharpCap 4 the first time you run SharpCap 4. After that, the two are separate and can go their own way. I don't think 3.2 had the focal length option, so the default when starting SC 4 for the first time should have been set to not use the focal length.

cheers,

Robin