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Beep6581 / RawTherapee

A powerful cross-platform raw photo processing program
https://rawtherapee.com
GNU General Public License v3.0
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D800 multi-exposure NEF files have wrong white balance #1686

Open Beep6581 opened 8 years ago

Beep6581 commented 8 years ago

Originally reported on Google Code with ID 1702

Use D800's multiple exposure function to produce a raw file. I tested with 10 identical
exposures, auto gain on (camera basically averages the images together, handy for reducing
noise).

Strong magenta cast is present in the NEF file when it is opened in Raw Therapee: http://i.imgur.com/PTdu2oF.jpg

Converted DNG file however will be normal: http://i.imgur.com/NRw5EIE.jpg

Branch: default
Version: 4.0.9.185
Changeset: b4aa66ef5205
Compiler: gcc 4.6.1
Processor: generic x86
System: Windows
Bit depth: 64 bits
Gtkmm: V2.22.0
Build type: RELEASE
Build flags:  -mtune=generic -fopenmp -O3 -DNDEBUG
Link flags: -mwindows -mtune=generic -s
OpenMP support: ON
MMAP support: ON

Win 7 x64.

NEF file will be uploaded shortly to: http://dl.dropbox.com/u/116542420/web/_DSC4687.NEF

Reported by Janne.Voutilainen on 2013-01-28 00:21:45

Beep6581 commented 8 years ago

Reported by torger@ludd.ltu.se on 2013-11-05 21:15:16

Beep6581 commented 8 years ago 
Link inaccessible (403), can't test. Please provide a working link.

Reported by entertheyoni on 2013-11-10 23:24:39

Beep6581 commented 8 years ago 
Here: https://dl.dropboxusercontent.com/u/168254285/web/D800_multiexposure_DSC_9840.NEF

Reported by Janne.Voutilainen on 2013-11-28 19:55:46

Beep6581 commented 8 years ago 
Reproduced in latest.

Reported by entertheyoni on 2013-12-05 02:06:18

Beep6581 commented 8 years ago

Still valid.

iliasg commented 7 years ago

I took a look .. The "as shot" WB used is ...

Looks like the RAW values are Pre WBalanced !!. Indeed if I inverse the WB factors in channel mixer (R=1/1.902 = 52, B = 1/1.380 = 72) the picture is correct

Going down with exiftool I find 0x0097 0x0000 (WB_GRBGLevels) = 256 256 256 256 This tag on normal files gives exactly the WB_RBLevels i.e for 1.902 1.383 it would be 256 487 354 256 So I guess DNG reads WB from 0x0097 http://owl.phy.queensu.ca/~phil/exiftool/TagNames/Nikon.html

Not sure if these 0x0097 tags always (I only checked 5 samples) give correct WB (I only checked 5 samples) nor which exactly from ColoBalanceXXXX exist and should be used