Digital photography white balance
White balance means the act of eliminating unrealistic color casts, in order to make the subject look more natural.
So for a proper camera white balance, “color temperature” of a light source has to be taken into account which is the relative coolness or warmth of white light.
This is often a problem as unlike human eyes (which are good at judging white objects even when under different light) the digital camera lens is not so good at auto white balance and can lead to unsightly orange, blue and even green color casts.
So if you want to avoid these color casts you will have to understand digital photography white balance, as it certainly helps in improving photography results under an array of lighting conditions.
In this article we will cover white balance thoroughly to make it easier for you to grasp. We will begin by giving a background of color temperature and then move on to the workings of white balance:
What is Color Temperature?
Color temperature is used to describe the spectrum of light that is radiated from a “blackbody” (object which doesn’t reflect nor lets light pass and absorbs all incident light) and with that surface temperature.
A rough correspondent of blackbody radiation in daily life will be heating a stone or a metal which become “red hot” at one specific temperature and turn “white hot” at higher temperatures.
Likewise, blackbodies also have varying color temperatures of “white light” at different temperatures. So the color distribution becomes cooler as the color temperature rises.
Why is color temperature useful?
This is because light sources like tungsten bulbs and daylight closely copy the distribution of light created by blackbodies, though sources like fluorescent and the majority of commercial lighting do not follow the blackbodies rule.
Auto white balance is present in all digital cameras and makes uses a calculated algorithm that is within a range of 3000K and 7000 K mostly. In “Kelvin” photographer is allowed to set the color temperature over a wide range. These white balances allow a range of color temperatures.
Now coming onto the next six white balances, they are ordered according to the increase in color temperature. You may not find ‘shade’ white balance in compact cameras.
There is also a “Fluorescent H” white balance in some cameras, which is to be used while working in newer daylight-calibrated fluorescents.
Remember the actual light these white balances work best under, is just a rough estimate so you can use one in place of another if you feel it suits the circumstances well. For example, you can use cloudy in place of daylight if you think that the degree of haziness and the time of day allows it.
Moreover, even if the final results look too cool even when your settings were right, you can go further down on the list to quickly increase the color temperature.
Even then if the results are not satisfactory, then just use the Kelvin setting to manually set the temperature.
Also if all above fails and your results do not have the correct WB when you inspect them afterward, you can still adjust the color balance and remove additional color casts by using post-processing features.
You can use the “levels” tool in Photoshop with the “set gray point” dropper in colorless reference. But remember this method shouldn’t be used excessively as it severely reduces the bit depth of the image.
Why use the raw file format in practice?
So far I have witnessed that the best white balance solution comes when using the RAW file format. Make use of them if your camera supports, because it allows you to set the White Balance after capturing the photo while post-processing.
They also allow the photographer to set the White Balance over a wider range of color temperature.
Moreover, setting a white balance in a raw file is quicker and easier. You can do it in two ways. One by adjusting the temperature and green-magenta sliders so that the color casts are eliminated and the other by simply clicking on a neutral reference within the photo.
So even if only one of your results contains a neutral reference, you can use its resulting White balance settings for the rest of the photos if the lighting is the same.
Custom white balance – choosing a neutral reference
A neutral reference is mostly used in color-critical projects and in circumstances where the photographer anticipates that the auto white balance might face problems.
If Neutral references are parts of your image then you’re lucky, otherwise you carry it as a portable item. Portable references usually are very expensive if they are specifically designed for photography, but do include less expensive household items such as a Pringles container or the underside of a lid to a coffee.
They are both reasonably accurate and inexpensive but are no match to the custom-made photographic references which are indeed the best. On the other hand, you can make use of pre-made portable references that are mostly accurate since it is easy to trick one into thinking that the object is neutral when it is not.
Whatever device you use, jut ensure that care is taken when making use of a neutral reference with high image noise.
Auto white balance keynotes
Remember that not all subjects can be captured using a digital camera’s auto white balance, as some can create problems even under normal light conditions.
For example, is if the scene already has an overabundance of coolness or warmth then the camera then tries to compensate for this and unknowingly creates a color cast. So digital cameras are susceptible to this and some are more than others.
Thus make use of a digital camera’s auto white balance when the photo contains at least one white element as it is more effective than.
This is because the absence of white elements can cause problems and the camera’s auto white balance will mistakenly create an image with slightly warmer or cooler color temperature.
White balance in mixed lighting
Multiple illuminants can complicate the setting of white balance as they have different color temperatures. So under mixed lighting, usually an auto white balance calculates the average color temperature of the entire scene.
This is an acceptable approach however it exaggerates the difference in color temperature for different light sources as compared to what our eyes see. And these exaggerated differences in color temperature become more prominent when in indoor.
I hope this article was helpful for you and cleared all your queries regarding white balance. Don’t forget to apply what you have learned in real life, as you won’t become proficient until you practically use it!