Image statistics, Min/Max values

Image processing, astrometry, photometry, etc.
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Rudi
Posts: 152
Joined: 08 Jan 2019, 04:47

Image statistics, Min/Max values

Post by Rudi » 01 Apr 2019, 09:18

Is the Image statistics Min/Max values ADU values?
How does AstroArt calculate the values?
For my Canon 1000D (12-bit) Max values never reaches the expected 2^12-1=4095 but is always arround 3500 to 3600.
/Rudi

Dunmunro
Posts: 225
Joined: 10 Jan 2019, 01:11

Re: Image statistics, Min/Max values

Post by Dunmunro » 01 Apr 2019, 16:35

Rudi wrote:
01 Apr 2019, 09:18
Is the Image statistics Min/Max values ADU values?
How does AstroArt calculate the values?
For my Canon 1000D (12-bit) Max values never reaches the expected 2^12-1=4095 but is always arround 3500 to 3600.
What is the min and background values? IIRC, Canon adds an offset which then reduces the ADU range available for the signal.

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Rudi
Posts: 152
Joined: 08 Jan 2019, 04:47

Re: Image statistics, Min/Max values

Post by Rudi » 02 Apr 2019, 06:06

Dunmunro wrote:
01 Apr 2019, 16:35
What is the min and background values? IIRC, Canon adds an offset which then reduces the ADU range available for the signal.

Code: Select all

Name  ...........  #3 ngc4631-480s-3_024.fit
Path  ...........  C:\Users\rbr\Dropbox\Main\astro\2019\0401\
Size  ...........  3906 x 2602
Telescope  ......  12 42.3  +32 25
Pixels  .........  10163412
Min  ............  3 @ 3016,149
Max  ............  3651 @ 1210,6
Background  .....  327
Average  ........  327.93809
Sum  ............  3332969910
Std.deviation  ..  45.949128
/Rudi

Dunmunro
Posts: 225
Joined: 10 Jan 2019, 01:11

Re: Image statistics, Min/Max values

Post by Dunmunro » 02 Apr 2019, 08:56

what exposure time are you using?

Does the ADU reach 4096 during terrestrial photography?

This article may be of some use:

http://www.stark-labs.com/craig/article ... earity.pdf

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Rudi
Posts: 152
Joined: 08 Jan 2019, 04:47

Re: Image statistics, Min/Max values

Post by Rudi » 02 Apr 2019, 12:20

It’ a 480[s] exposure.
A loooong daytime exposure shows the same, saturated values around 3500-3600.
I feel like Canon has only sold me a 11 3/4 bit camera 😜
/Rudi

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