Tech Support
Adjusting white balance – raw only?
Q Excuse my ignorance, but I am relatively new to this and expect my question goes beyond Lightroom. I thought that one of the advantages of capturing raw images as opposed to JPEGs is that you can change the white balance. Lightroom seems to allow me to change the white balance on JPEG files as well. What am I not understanding?
John (AP forum)
The white balance of an image iscorrecting white balance in raw files is that you get a more accurate result. See the pictures of the orchid bloom here. I shot the pictures in raw and JPEG at the same time, deliberately in daylight with the camera set to tungsten light colour temperature. Both the unadjusted raw file (A) and JPEG version (B) have, as you would expect, a blue cast. But look what happens when the same target area was used to correct the white balance. The raw file produced a natural-looking result (C), while the JPEG (D) colours are wrong. This is because the colour channels in the raw file are still discrete. They can be adjusted independently at the pixel level. With JPEG, the pixels are made up of colours that have already been mixed from the separate channels, making overall adjustment much less consistent. My example is an extreme one to demonstrate the point. Fortunately, this inherent inconsistency is less obvious where the white-balance error is not so extreme in JPEG images. So yes, you can correct white balance in JPEGs, but beware of inconsistencies compared to correcting it in raw files.
