Integer vs floating point capture

CCD cameras (CMOS/CCD), DSLRs, telescope mounts, focusers, autoguiders, domes, Roll off roofs, etc..
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keving
Posts: 53
Joined: Thu Dec 14, 2017 4:49 am

Sat Nov 03, 2018 10:49 am

Having run into some issues with data formats, I revisited this recently.

My camera (an Atik 460EX) delivers 16-bit output, presuambly rendered as 0 to 65535.
However, I see the integer format in Prism is 16-bit signed

Does this mean I can only represent pixels from 0 to 32767? Do I lose 1-bit of accuracy?

Kevin
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keving
Posts: 53
Joined: Thu Dec 14, 2017 4:49 am

Sun Nov 04, 2018 10:06 am

Having done some further investigation, I am pretty sure the 16-bit integer format stores with 15-bit resolution
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kora
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Tue Mar 10, 2020 7:05 am

We have reviewed what you have described. I'm using an ATIK 383L + 16 bit ccd camera. First: I checked my image for the usual fits test. The Prism Fits header contains 16 bits and the maximum ADU pixel value is 65535.
Prism_16 bit.png
Under Linux with Siril, the test image data is 16 bit color depth.
Siril_16bit.png
Under Linux, SAOimage DS9 has 16 bits and 65535 (max) values ​​in the pixel value table in the galaxy core.
SaoimageDS9_16bit.png
Did you mean this under the 16-bit Prism / Settings / Software Setup / Images (JPEG / TIFF) tab?
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kora
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Tue Mar 10, 2020 9:12 am

Prism pixelgrid really shows a different meaning!!!
What could be the explanation for this?
Prism pixelgrid.png
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