Lightroom changes the WB of some photos automatically, but not others

[bomberman]

Help!

For some reason, out of an entire shoot lighroom will decide to change the WB and Tint on around 1/4 to 1/3 of the photos. It's not until i actually select the photo in the viewer that the change occurs, so everything imports fine until the photo is selected and then after a second or two the WB changes. What's annoying is that it can happen on two photos with exactly the same lighting taken seconds apart, usually controlled lighting, and it's almost impossible to get the WB back to being the same on those two photos. It seems to be completely random as it adjusts the WB for some but not others. If i look at the settings on the right i can see that the histogram has changed and the WB slider moves to the left and takes on a different numerical scale. Instead of the middle being zero and left of the middle being -XXX they are left of the middle and reading 5800. Can anyone explain what's going on here? It's causing me a headache!

 

[DazJW]

One is a JPEG (.jpg) and one is a RAW file (.cr2). So the JPEG has the camera white balance "baked in" to the image file but the RAW file is being set to whatever Lightroom's default is set as.
The scales are different because with JPEG the white balance adjustment is relative (warmer/cooler than original iamge), while with RAW it's absolute (a set temperature in k).

 

[bomberman]

That is a very good spot, Thanks.

Next question is - why is LR importing a random mix of RAW and Jpeg? I'm shooting in 'Raw with large fine Jpeg' in my camera settings so all the photos should have a RAW file.

 

[Byker28i]

Are you shooting raw and jpeg? If you pop intoi the library module and select view, sort, by capture time, it might help identify the file pairs easier

 

[bomberman]

Hi yes i am shooting RAW + Jpeg. I've done that and there are no identical pairs - some are RAW files some are Jpeg. It did this on the last batch i imported. I've had a look on the card and all the original RAW+Jpeg files are still there but i can't understand why LR is importing some as one and some as the other?

 

[DunkWemyssBay]

The Raw and Jpeg versions are not by any chance getting stacked after import

 

[haggis]

Are you swapping shooting modes between AV, TV, Manual, Auto during the shoot? Some cameras (you've not said what you're using) but some will revert to either Raw or Jpeg only for certain settings IIRC.