Optional stretching of 12 bit s image saved using the FITS format

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db48
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Optional stretching of 12 bit s image saved using the FITS format

Post by db48 » Thu Feb 22, 2018 1:54 pm

Hi,
I tried to use the new feature of SC 3.1.5047 related to the optional stretch of a 12 bits image when saved using the FITS format (RAW 16 colour space). I use a ZWO ASI 174MMC camera with a 12 bits ADC onboard. However the saved FITS image is always stretched to 16 bits, indipendently from the fact that I check/uncheck the corresponding button in the General Setting menu. Where am I wrong?

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admin
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Re: Optional stretching of 12 bit s image saved using the FITS format

Post by admin » Thu Feb 22, 2018 5:49 pm

eeek - turns out that's Altair cameras only at the moment as the other cameras do not currently report their true bit depth. I can see an API that looks like it may work for QHY, but nothing for ZWO :(

Better update the UI to flag this limitation for now - thanks for the report.

cheers,

Robin

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Re: Optional stretching of 12 bit s image saved using the FITS format

Post by admin » Thu Feb 22, 2018 9:08 pm

Having looked into this further, there is no obvious way to get the ADC bit depth from the SDK for ZWO or QHY cameras. I could use the values calculated by sensor analysis, but that would require (a) people to do sensor analysis before this could work and (b) some substantial changes to the code... Both of these would rule that option out for the current phase of development where I am fixing bugs and making small, safe change if necessary.

I've contacted both manufacturers to see if they can provide this info in a future version of their SDK.

cheers,

Robin

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oopfan
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Re: Optional stretching of 12 bit s image saved using the FITS format

Post by oopfan » Fri Feb 23, 2018 11:34 am

Confirmed that saving image to native 12 bits works for Altair 290M.

Thank you.

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