Here are some thoughts on white balance. I hope they help you understand the concept better and leads to improving your photos.

What is white balance?

When taking colour photos the type of light illuminating the scene affects the details that are recorded on the photo. Some light wavelengths will record stronger than others and how they interact with the objects in the scene will affect the apparent colour of those objects. Scientists developed a scale that measured the balance of colours in light. They used a Kelvin scale to rate the temperature of light and provide a standard measure of light. To get the right colour photo  results the ‘film’ needs to be rated for the colour temperature of the  light illuminating the scene. The use of incorrect colour temperature will result in a colour cast across your photo. This is most evident with film cameras when using daylight film indoors with tungsten or fluorescent lights on.

What effect does it have?

As stated above the setting of the colour temperature in your film medium/sensor will affect the way the light is recorded on your images. What happens is the medium is more reactive to particular wavelengths and they will be more prominent on the image. In particular the medium will record reflected light from the scene with a prominence of certain wavelengths. This results in the colour cast and causes your images to be tainted in that tone. The best way to see this is to get a white object and use either film or set your white balance on your digital camera manually and then illuminate the object with different kinds of light sources. You will see the change in the colour of the white object.

Can I change it?

Thankfully, yes you can change the white balance of your medium. In film there are different colour balanced films. You can also get filters which compensate for the variation in the light from your film’s rating.  Fortunately with digital cameras there is the ability to select the white balance on the camera and it is adjusted electronically in the camera. This is a feature of digital cameras which I think is really cool.

What setting should I use?

The setting to use is dependent upon what light sources you have and, to add to the confusion, what end effect you want to achieve. If you want that warm reddish glow of the sunset to dramatise your photo then don’t adjust your white balance for the sunset, leave on daylight and the red wavelengths will feature in your image. Digital cameras tend to have daylight, tungsten, fluorescent, flash, auto and custom. There may also be cloudy and shade in the selections too. If you know the colour temperature of the light then select the appropriate setting for that light. Midday with strong sun is going to use daylight. A Cloudy day will use cloudy. Indoors with incandescent globes will require tungsten likewise fluoro tubes will need the fluorescent setting.

To complicate matter there are frequently times when there are multiple light sources affecting your scene. This is where auto comes to the fore. The camera can measure and adjust the white balance to match the scene. Modern cameras are getting much better at making these adjustments and now generally get it right all the time.

Getting you white balance right before taking the shot is very important if you are shooting in jpg format. With jpg the colour temperature is recorded in the image. If you get it wrong it is wrong in the image. It can be fixed most of the time but will require some effort in post processing. This is where digital cameras which shoot in RAW have the upper hand. If you get the white balance wrong in RAW image it doesn’t matter. open you image in your RAW editor and change the white balance. Its as easy as that.

Even in RAW it is best if you get the white balance right in camera as the image will be saved with that setting and it will speed up your processing if you don’t need to change white balance. However, if you venture out on a photo shoot and leave the white balance on one setting you will be able to adjust the image to what you remember the scene looking like after the event on your computer. How good is that. One tip I learn from Ryan Brenizer was for your shoots to pick a white balance for a group of shots and stick to it. Don’t use auto. Auto setting will cause the camera to adjust for every photo and every little nuance in the light will be adjusted for causing the white balance of your photos to change every time. This helps when processing lots of RAW shots. Get the white balance right for the first shot in a batch for a scene and then synchronise the rest to match. Big time saver! Also have a look at Michael’s blog on white balance and see how to use a gray card to get your white balance just right.

Can I see an example?

Sure. I was taking the time to record our new lights in our path the other night. I had the white balance set to daylight and stuck with that through the shoot. the biggest thing about that was the only source of light that night was from these little tungsten globes illuminating my path. The feel of the images were very different from what I had seen with my own eyes. No problem I just adjusted them to tungsten in Lightroom 2 and Bob’s my uncle the image represented what I had seen that night.

So the first image here is taken in daylight. you can notice the orange glow across the image. It really affects the feel dramatically and in my opinion loses impact.

The second image I have adjusted to tungsten and the feel is back and the impact is what I was looking for.

One note I would say is that the daylight temperature has made some detail more visible. It does, though for me, lose the grab you factor and comes across muddy. Some people will like that picture more than the second and that is not wrong. One of the joys of art is that the subject is subjective and dependent upon the viewers point of view and preferences. So get out there and practice your art and play around with your white balance to see how it works.

If you like this please let me know.