ASI294: "data is only 8bits, APP will NOT perform data calibration

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Swader_az
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Joined: Wed Sep 09, 2020 12:03 am

ASI294: "data is only 8bits, APP will NOT perform data calibration

Post by Swader_az » Wed Sep 09, 2020 12:27 am

I cannot figure this out, I believe I am capturing @ 16bith:

[ZWO ASI294MC Pro]
Debayer Preview=On
Pan=0
Tilt=0
Output Format=PNG files (*.png)
Binning=1
Capture Area=4144x2822
Colour Space=RAW16

But when I ANALYSE STARS I always get the WARNING:

[CRITICAL WARNING: data is only 8bits, APP will NOT perform data calibration...
To be able to perform accurate data calibration,
you will need to provide 16bits or 32bits data to APP.
8bits data will not work, it will lead to very bad and strange results.
APP will now abort data calibration...


What should I be capturing at?

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admin
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Re: ASI294: "data is only 8bits, APP will NOT perform data calibration

Post by admin » Wed Sep 09, 2020 5:47 pm

Hi,

you should definitely be capturing in the RAW16 mode. If you are saving to PNG file then SharpCap will be writing the 16-bit data into the PNG file, but some programs aren't capable of properly reading 16 bit data from PNG files – if you load it into many popular image editing applications then they will correctly load the image but drop the data down to 8 bit. I wonder if this is happening in APP? The best way to test would be to capture to FITS format instead – if that works fine with no other setting changes then it's most likely a problem with APP not reading 16 bit PNG files correctly.

Hope this helps, Robin

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turfpit
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Re: ASI294: "data is only 8bits, APP will NOT perform data calibration

Post by turfpit » Wed Sep 09, 2020 6:24 pm

APP supports FITS, TIFF & JPG (not PNG). You could use PIPP to bulk convert your PNG files to one of the supported formats and see if that helps. See viewtopic.php?f=35&t=254

If you are using APP for processing the normal (good) practice would be to supply FITS format files for calibration and integration as the FITS headers contain information which is useful to the software in obtaining the best possible outcome.

Dave

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