Color Compensation (Film) & White Balance (Digital)

Film expects to see a color temperature of 5,500° Kelvin - mid-day sun to reproduce color reasonably realistically.  Digital cameras also expect a particular color temperature, but are more easily adjusted. Since we don't always have mid-day sun, we have several choices. 

 

Use the light as it is.
Add light to the scene so the resulting light better approximates 5,500° Kelvin.
Modify the light so it better approximates 5,500° Kelvin

 

Use what you have
You may decide to use the light you have.  If it's cloudy, your colors will be muted and cold - more blue-toned.  If you're indoors shooting by the light of light bulbs, your images will be very warm - red/orange-toned.  These may be effects you want.  Sometimes they work very well in a photograph.  But, it may not be.  You decide. As long as you understand how the film will record the light you're have, you're in control.

 

Add light
You can add light.  This is most commonly done using electronic flash.  A very good way to add light using electronic flash is "fill-in" flash so that you are not providing ALL of the light, but are using some of the ambient light available.  You can even "color" the light of the electronic flash by using colored filters over the flash.

 

Modify the Light - using Film
You can easily modify the light so that the film "thinks" it's seeing 5,500° Kelvin light. This is commonly done with filters.  The following chart shows the relationships between different types of film (on the right), different kinds of light sources (° Kelvin) and different filters (in the center).  For example, when shooing with daylight film and using a 3,000 ° Kelvin light source, you would want to use a 80A filter - where the line drawn from the film type to the light type intersects the Mired value. (Note: MIRED is an acronym and is related to color temperature).

 

Warming Filters
 The most commonly used color compensation filters are the 81A and 81B. These filters add warmth to a scene.  The 81A adds a little warmth while the 81B adds a bit more.  You should own one of these.  These are most commonly used on cloudy days.  They will warm the light enough so that the film will "think" it's seeing mid-day sunlight - even if it's overcast and maybe even raining!  By warming the light to approximately 5,500 ° Kelvin, the colors of the scene will be recorded properly - just the way you saw them because your brain intercepted your optic signals and instantly put a biological 81A filter in place!

 

Color Compensating Filters
The following  list shows which color compensating filters can be used in what situation.  The "Adjust" column indicates how much of your exposure will have to be compensated.  If you are using the light meter inside your camera, you won't have to worry about this as the amount of light reaching the light meter will already have been reduced.  This is only significant if you are using a hand-held meter.

The difference between an using a tungsten light-source with daylight-balanced film: unfiltered and filtered:

 

Modify the Light - using Digital
Digital cameras don't need color compensating filters.  They have a feature called "White Balance".  The white balance refers to the compensation that can take place in the digital camera to "correct" the color of the light.  Most digital cameras have options such as:  Automatic White Balance, Daylight, Tungsten, Fluorescent, Cloudy, Flash, Preset, etc.  When set to "Automatic" - usually the default for a digital camera - the camera tries to make an intelligent decision as to what color the light is.  But it usually only works within a small range of light (i.e., 3,500° - 7,000°) and doesn't always work that well.  If shooting on a cloudy day, you're always better off to select "cloudy" than "automatic".  Just don't forget to set it back!  The best option is to use the PRESET option if your camera has it.  This allows you to "measure" the color of the light using a white or neutral gray object.  This way you're always assured of the best color compensation.

Even when taking RAW images you need to properly adjust white balance!  Here are 4 images all taken with tungsten light - the first three are RAW and the last is a JPG.

1. The first image was taken as RAW and AUTOMATIC white balance.
2. The second image was taken as RAW and TUNGSTEN white balance.
3. The third image was taken as RAW and a measured PRESET white balance was used.
4. The fourth image was taken as a JPG and a measured PRESET white balance was used.

 

The last three images have the best white balance.  The "Automatic" white balance (first image) is the worst - the reason for this is the automatic setting can't compensate enough for tungsten light. The last two are the best (although you wouldn't know what the real colors are, these are the most realistic).  You can especially see a difference in the background colors. The lower background was black text on white paper.

The first three images were RAW images and could have been easily modified to correct for the incorrect white balance, but... EVERY correction you make in an image reduces its quality.  Shoot an accurate white balance up front and you get a better image and save yourself time on the computer!