Frustrated...going backwards

Questions and answers about processing in StarTools and how to accomplish certain tasks.
Pscm

Re: Frustrated...going backwards

Post by Pscm »

Ok, so I am not sure exactly what you ask so the attached was opened in ST and I selected Linear. I don't believe the image was stretched as all I see is the brightest stars. What I am not sure is your mention of bayered.
Attachments
Capture.JPG
Capture.JPG (14.42 KiB) Viewed 5618 times
Pscm

Re: Frustrated...going backwards

Post by Pscm »

And here is one from each camera read directly from the camera card.
Attachments
canon.JPG
canon.JPG (42.84 KiB) Viewed 5617 times
Nikon.JPG
Nikon.JPG (18.83 KiB) Viewed 5617 times
Pscm

Re: Frustrated...going backwards

Post by Pscm »

I forgot to mention the Nikon and Canon images were before the DSS and ST latest updates.
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Re: Frustrated...going backwards

Post by admin »

Thank you. Since all these are in color (and don't show a Bayer pattern), they all have been debayered by software.
It's quite possible that "Capture.jpg" has not been white-balanced yet, so that would be good and would allow you to use the second option when opening the final stack in StarTools.
But, like I said, without any further information/documentation about what your software is doing, we can't draw any firm conclusions.
Ivo Jager
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Pscm

Re: Frustrated...going backwards

Post by Pscm »

To clarify, "capture" was from the nikon and pulled from the ASIAIR as a fits file and was stacked in DSS with "no white balanced" ticked. The "Canon" & the "Nikon" was from that camera and its SD card and stacked in DSS before the "No white balance" option was available. Does this help?
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Re: Frustrated...going backwards

Post by admin »

Ah, so these excerpts are all from stacks, rather than from individual frames?
My question then would be, what does an individual FITS file look like, as produced by ASIAIR?
If that is mono and shows a Bayer pattern, then you are in business.
Ivo Jager
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Pscm

Re: Frustrated...going backwards

Post by Pscm »

I am away for a couple of weeks. When I get back I will have a look. Thank you for the assistance.
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Re: Frustrated...going backwards

Post by saublestarman »

I am an experienced D5300 astroimager and I have seen a few things mentioned here that maybe I can help with.

The D5300 is advertised as a 6000 x 4000 image size camera but when the image files are read by Deep Sky Stacker they are 6016 x 4016. This slightly larger file size happens because DSS uses DCRAW to read DSLR RAW files and the RAW file size for the D5300 is 6016 x 4016. Even after stacking the resulting files will always be 6016 x 4016...unless you decide to use a 2x or 3x drizzle method. This is because DSS chooses a "BEST" image from all of the available images in the stack and then builds up the stack by shifting the next image as needed and then cropping the sides as needed so that the final image size does not change. It does not matter how much dithering you use...the resulting file size will always be 6016 x 4016. I don't dither at all and my images are always 6016 x 4016.

The RAW file type for the D5300 is *.NEF. The only other format supported natively is *.JPG. I worry that if you are getting *.FITS from the ASIair then you need to find out how these files are created. The ASIair supports a large number of Canon and Nikon camera so I expect the ASIair is using either DCRAW or LibRaw to decode the files. There are so many options with these two pieces of software that it's very hard to determine whether the data you are getting has been debayered or color balanced.

You mentioned that when you got your D5300 you also started using your ASIair. I would suggest that you either configure ASIair to store the images in RAW (*.NEF) format (if possible) or you change the setting in the D5300 to store the image on it's SD card as well. I think you should be comparing results obtained using *.NEF formatted images with ASIair *.FITS images. The *.NEF will always be the best the camera can create. You need to see if the *.FITS file that the ASIair creates are the same quality.

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Re: Frustrated...going backwards

Post by saublestarman »

Another way for us to learn a little more is to open one of your FITS files using notepad. The beginning of the file has some text that describes the file. The rest is totally unreadable. If you could post a reply here and simply cut and paste the text from the beginning of the file into your post then we could learn some more about what the ASIair is doing.

Peter
Pscm

Re: Frustrated...going backwards

Post by Pscm »

Here is the data from a DSS stacked file that the ASIAIR converted to FITS:
SIMPLE = T / file does conform to FITS standard BITPIX = -32 / number of bits per data pixel NAXIS = 3 / number of data axes NAXIS1 = 6016 / length of data axis 1 NAXIS2 = 4016 / length of data axis 2 NAXIS3 = 3 / length of data axis 3 EXTEND = T / FITS dataset may contain extensions COMMENT FITS (Flexible Image Transport System) format is defined in 'AstronomyCOMMENT and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H EXPTIME = 2400. / Exposure time (in seconds) EXPOSURE= 2400. / Exposure time (in seconds) SOFTWARE= 'DeepSkyStacker 4.2.3 Beta 1' INSTRUME= 'Nikon DSC D5300' / Camera model TELESCOP= 'Celestron AVX/CGE/CGEM/CGX' / Telescope name RA = 43.1793 / Object Right Ascension in degrees

And here is a DSS stacked file that was taken from the camera's card:
SIMPLE = T / file does conform to FITS standard BITPIX = -32 / number of bits per data pixel NAXIS = 3 / number of data axes NAXIS1 = 6016 / length of data axis 1 NAXIS2 = 4016 / length of data axis 2 NAXIS3 = 3 / length of data axis 3 EXTEND = T / FITS dataset may contain extensions COMMENT FITS (Flexible Image Transport System) format is defined in 'AstronomyCOMMENT and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H ISOSPEED= 200 EXPTIME = 7204.90026855469 / Exposure time (in seconds) EXPOSURE= 7204.90026855469 / Exposure time (in seconds) SOFTWARE= 'DeepSkyStacker 4.1.1' DATE-OBS= '2019-09-27T22:04:09' END

These are not the same image although I am in hopes it is enough to decipher

Further input is much appreciated!
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