One of the big advantages put forward for RAW files by experts is they make it possible to change the white balance setting later on. RAW files contain all the colour information captured by the sensor, whereas JPEGs, which have already been processed by the camera, have already had some colour data discarded according to the white balance setting used on the camera.
This makes a difference when you’re working on images in Lightroom, because the white balance settings look different for RAW files and JPEGs. This confuses a lot of people! But there is a simple explanation.
With RAW files, you have all the white balance options available on the camera itself, including the white balance ‘temperature’ and ‘tint’ settings. Lightroom can set absolute values, just as the camera can.
But with JPEGs, the white balance has already been set, so these settings can no longer be altered. Lightroom can still modify the white balance, but only by adjusting the relative values.
Many users expect to be able to set absolute temperature and tint values only to be confronted by these simpler +/- sliders, and it’s because they’re working on JPEGs not RAW files.
So does that mean that JPEGs are badly inferior to RAW files for white balance adjustments? In theory, yes, but in practice the differences may be a lot smaller than you expect, as the before-and-after comparison at the end of this walkthrough shows.
In the meantime, though, here’s how to adjust the white balance for both RAW files and JPEGs using the Lightroom White Balance Selector tool. I’m using two versions of this same image to show the differences.
01 RAW file white balance
Here’s the RAW version of my picture open in the Lightroom Develop module. The white balance tools are in the Basic tab, and there are two sliders here: ‘Temp’ and ‘Tint’. At the moment, these display the temperature and tint values of the white balance setting used by the camera. These sliders can be changed directly, which is effectively the same as changing the white balance on the camera.
02 White Balance Selector
Instead, though, I’m going to use the White Balance Selector tool – that’s the big eyedropper next to the sliders. I’m going to click on the white sheet over the altar in the centre of the picture – a pop-up panel shows a magnified view of the pixels you’re clicking on so that you can get a proper look at the colours you’re trying to ‘neutralise’.
03 Corrected RAW file
And you can see the result in both the picture, which now looks more neutral, and the Temp and Tint sliders in the white balance panel. To neutralise the colour, Lightroom has had to reduce the Temp value and increase the Tint. It’s utilising extra colour data in the RAW file that was not needed for the initial rendition but is still there.