What Is White Balance on Your Camera?
(Editor’s Note: This story is by photographer Patrick McNair. You can find out more about him on his website.)
Amongst all the settings on your camera you’ll find one for White Balance, usually contracted to WB. This might be a button on the camera body or a menu option or both. But what does it do exactly and how does changing White Balance affect your photos?
Not only do beginners find White Balance to be a confusing feature on their cameras, more advanced photographers also struggle with this adjustment and its effect on images. In this article, I will give you an explanation of what White Balance is and what it means for photography.
White Balance and Color
When we photograph a scene, we usually want all of the colors in our scene to be reproduced faithfully in the photograph. That is unless we are trying to be more creative.
If we were shooting in white light or daylight the chances are that all of the colors in our image would be the same as the colors in the scene. However, we aren’t always photographing in this type of light and it is more likely that we would be taking photos when there are clouds in the sky, or in low light when we need a flash, or under fluorescent lights indoors.
So, if we don’t have some way of “telling” the camera what type of light we are photographing in, it would probably “assume” that we were shooting in white light and the result would be that our photo would have a color cast in it.
The reason that this happens is that different types of light sources give off different colors. For example, an electric light bulb gives off a yellow color. The flame from a candle gives off a yellowish red color and Fluorescent lights have a slight blue color.
The White Balance setting on your camera is one way of letting your camera know what type of light you are photographing under.
Selecting White Balance
When you press the WB button on your camera, or you access the White Balance menu, you’ll be presented with a list of choices similar to those shown below:
From that list you would choose the type of lighting that is a close representation of the ambient light in your scene. So, if you are shooting on a cloudy day, that’s the WB option that you’ll choose, or if you are in a room lit by fluorescent lights then you would choose that option from the list.
When you do this, the camera will compensate for the fact that you are not shooting in white light or daylight and it will adjust the colors in your image accordingly so that they match as closely as possible the original colors in the scene you are photographing.
You’ll see that, among the white balance options you have one that says “Auto.” Just like any other auto setting on your camera, that option gets the camera to make the choice for you.
If you select Auto, the camera will use its built-in light meter to determine what type of lighting is illuminating the scene and it will attempt to compensate appropriately. However, it doesn’t always get it right and so, if possible, it is a better option to set the WB yourself manually.
You’ll see that not all of the possible light sources are catered for in the white balance settings and your available choices are pretty generic. A cloudy day where I am, for example, might not be the same as a cloudy day where you are. Modern cameras will normally also have a more accurate way of setting white balance based on color temperature.
Don’t think of color temperature in the same way we describe the temperature of something that gives off heat. Color temperature is used to describe the appearance of light and it is measured on a scale called Kelvin (K). You don’t really have to understand the physics of color temperature only that it can be used to describe the color of the light source that you are photographing in.
The following chart shows the color temperatures of the most common light sources that you would find illuminating scenes.
On your camera somewhere you’ll either see a scale or a grid similar to the one below.
You can use the cursor keys on your camera to position the cursor over the color on the grid that closely matches the color cast you are seeing in your test photos for the scene you are photographing. For example, if the color cast in your photo seems to be slightly blueish then you would set the kelvin temperature to one that goes towards the yellow color temperatures e.g., around 3000K. If the color cast is yellowish then you would move towards the blueish color temperatures e.g., 5000K. Of course, with this approach you are having to take test shots at each adjustment.
An easier approach is to switch the camera to live mode and look at the screen after every adjustment to see how the colors appear to the camera.
You can also set the white balance using a card, normally called a gray card. This card is usually 50% gray. You’ll sometimes get a card like this in a photography book, or you can buy them online.
The way that this works is that you place the gray card in the scene with the scene being illuminated by the light that you will be photographing under. You would take a photo of the gray card with the card filling the entire frame of the photo and use this in your camera’s custom white balance settings to “tell” the camera that this card should be gray. Once the camera knows that this is what gray looks like under that lighting it can then adjust the colors in the scene to appear as though they were shot in white light.
The menu options for this differ from manufacturer to manufacturer so it is worth checking your camera manual or videos on YouTube for specific instructions relating to your make and model of camera.
There is another way that you’ll see these gray cards used and that is in studio photography where a portrait photographer, who is shooting with the camera tethered to a computer, would place the card in the scene lit as they intended and then take a test shot. They could then use a dropper tool in the software to “tell” it that this should be gray and, as they take subsequent photos, the software adjusts each image as it is taken to compensate for the lighting.
All this will work as long as the lighting in the scene is not changed. If it is then the process needs to be carried out again.
As a final note, there will be times when situations make white balance more of a challenge. For example, you may be photographing in environments where the ambient light is made up of different types of lighting which.
Taken together, create a mixed lighting scenario. There are ways around this, both in camera and later in post-production but meeting a challenge like that is for a later discussion.
Published at Thu, 13 May 2021 18:01:35 +0000