Author Topic: Plate Solving with JPEGS?  (Read 87 times)

RichardB

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Plate Solving with JPEGS?
« on: April 07, 2019, 07:57:45 AM »
Hi,
I have been trying to plate solve - both blind and with local UCAC4 for jpeg images but no luck thus far.  I have varied every input possible but still not luck - I get the error message every time.  The images are large - 4928 x 3264 pixels - taken with Hyperstar and representing approximately 1.75 x 1.15 degrees.  Pixel size is 4.78 x 4.78. I have reduced the frame size as suggested in the error message but no effect.

The image is correctly oriented - it is mirrored to compensate for the telescope.  I am not aware of any place to enter a position angle - is this needed?

I would very much appreciate any help as this is what I purchased the Observatory software for.


Thanks for you help.

Richard

Sander Berents

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Re: Plate Solving with JPEGS?
« Reply #1 on: April 07, 2019, 12:07:43 PM »
Hi Richard,

When you tried blind plate solving, did you also try it with the option "Upload whole image"? Is there any particular reason why you are using a JPEG for this? You may have more luck with FITS or a RAW image format because JPEG has such limited dynamic range and the star detector may reject the stars, thinking they are over-exposed or even hot pixels. Is this a monochrome or RGB image? An image with such large FOV shouldn't require UCAC4. Observatory's built-in Tycho-2 catalog should suffice. If nothing works, then please share one of your images using Dropbox with support@codeobsession.com, so I can take a closer look.

Sander
Sander Berents
Code Obsession, LLC
http://codeobsession.com

RichardB

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Re: Plate Solving with JPEGS?
« Reply #2 on: April 07, 2019, 05:30:41 PM »
Hi Sander,

Yes, I tried "upload whole image".  The camera is a Nikon D7000 DLSR and the images are Fine JPEG colour.  I'll try a Raw image and see how that goes. I'll also set the catalog to Tycho.
I'm hunting for comets (have been since 1980 - closest call was in 2007 just arc minutes from Terry Lovejoy's second comet :-[)

Thanks

Richard