White Balance and RAW files
I have trained quite a few people over the last few years and have noticed that there seems to be quite a bit of confusion over white balance and RAW files. For the work that I do using the manufacturers RAW file option gives me the best results. This means that it ignores most of the cameras internal settings such as picture profile, contrast, sharpening etc and instead lets you have the data that came off the camera sensor for you to process. This in many ways simplifies the process of photography in that you have four main things to worry about:
- Shutter Speed
One thing that is commonly discussed is White Balance and how it is handled in the RAW files. The best way to try and describe it is that the white balance that you have set in your camera is stored as a setting in addition to the data from the sensor. It doesn’t change the actual data stored in the RAW file but is overlaid on to it to give you the image that you see on screen. So, by changing the white balance you are changing the way the image is displayed. This means that it doesn’t really matter what you set your white balance to if you are shooting RAW, you can correct it as part of your post processing routine without losing image quality. When I’m photographing a wedding I shoot the whole day on flash white balance. This is slightly warmer than daylight and works well for the natural light shots. I don’t change it when I’m indoors (it gives me one less thing to need to change) and I correct it when I’m post processing.
If your white balance is set to a constant i.e. “flash” then you can easily correct one image and copy that correction to a whole range of images. As part of my workflow I will normally correct the white balance and exposure (if needed) on the first image in a series and copy those adjustments across before I make any other changes.
To prove that the in-camera white balance does not affect the corrected image I setup my colour card and white balance/exposure cube in the studio. I used my Lowel-id video light to light it and used my light meter to work out the exposure. The exposure setting was ISO500 1/125 sec f5.6. The photographs were taken with the Sony A7s and the 23-70 Zeiss lens at 40mm (this gave me the framing I wanted).
I set the cameras white balance to Daylight and then to Incandescent (tungsten) and shot the same scene.
Daylight White Balance
This photograph shows the image as it was imported in to Lightroom. You can quite clearly see the orange glow from the video light. The white balance was 4800 +11
This is the white balance corrected image (using the white balance picker tool) and the white balance was 2950 +5
Tungsten White Balance
This shows the image as imported in to Lightroom when the white balance was set to Incandescent (Tungsten). The white balance used was 2750 + 8
After correcting the photo with the white balance picker tool it was 2950 +6
So, what did I conclude from all of this ??
1. It really doesn’t matter what you set your white balance to if you are shooting in RAW; you can correct it afterwards and it makes no difference.
2. You really do need to shoot a grey card/cube etc if you are in any sort of mixed lighting scenario or if accurate colour is critical. You can’t rely on being able to find something neutral grey in your scene; life is never quite that kind !
3. If you are shooting in a known lighting environment then either set your camera to the closest preset, use the kelvin controls on your camera (if it has them) to set your white balance or create a custom white balance and use that. All this will mean is that you then don’t have to correct white balance in your post processing.
The practicalities of this for me at weddings mean I choose to shoot the whole day on a fixed white balance and change it later. In the studio I try and get it right in camera 😉