Page 1 of 1

Image statistics, Min/Max values

Posted: 01 Apr 2019, 09:18
by Rudi
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.

Re: Image statistics, Min/Max values

Posted: 01 Apr 2019, 16:35
by Dunmunro
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.

Re: Image statistics, Min/Max values

Posted: 02 Apr 2019, 06:06
by Rudi
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

Re: Image statistics, Min/Max values

Posted: 02 Apr 2019, 08:56
by Dunmunro
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

Re: Image statistics, Min/Max values

Posted: 02 Apr 2019, 12:20
by Rudi
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 😜