why does white balance bracketing write three raw files?

[charles_martin8]

On my EOS I am shooting RAW + JPG. When I shoot with white balance

bracketing, the camera writes three CR2 files and three JPG files. But

WB does not affect the raw files... seems like it should just write

one CR2 and three JPGs. This makes a big difference in CF card usage.

 

Is there a real reason for 3x raw files?

[godfrey]

Probably just simplistic programming... they write a separate CR2+JPEG pair per bracket

adjustment. I've never seen much point to WB bracketing when saving RAW format files.

 

Godfrey

[wbowman]

I'm with Godfrey on this - there is little use in white balance bracketing when shooting RAW.

If the camera didn't write three files when bracketing then Canon would probably get a ton of

support request asking why there <b>aren't</b> three files!

[briany]

WB doesn't really affect the RAW data written, but there is a tag in a RAW file that tells the RAW converter what the WB "should" be. If there aren't three files, how is your RAW converter going to apply three different settings to the file when you open it? Where are the three settings going to be stored? Sure, it would make sense to have one RAW file and three "settings" files, but that's very non-standard and even if your Canon RAW converter knew what to do, other RAW converters wouldn't. As others have said, WB bracketing makes little sense with RAW, but each RAW file does have a WB tag embedded in it.

[digitmstr]

>>seems like it should just write one CR2 and three JPG<<

 

That is not possible since the camera is set to shoot RAW+JPG for every frame. TO change that Canon would have to write a different software.

 

Also, there is some reason to do it as it is: when you look at (or catalog) the pictures it's best to have a JPG for each *corresponding* RAW file if that is the way they were shot.