Photography Color Temperature

Color temperature is a means of measuring the energy level of color and is expressed in degrees Kelvin (K).


Each color on the visible spectrum is assigned a Kelvin temperature or, more accurately, a range of temperatures, so knowing the color temperature of a light source at any one time gives us important information about the quality of the light.

 

Some information on color temperature in film photography:

  • For color film, at the warm red end, small shifts in color temperature will result in large changes in color rendition on film. At the cool end, however, small shifts in color temperature result in comparably less change in color rendition. Thus, color films that are designed and balanced for daylight are able to produce acceptably accurate color under a wide range of natural or electronic-flash lighting conditions.

  • Films balanced for tungsten illumination only respond and deliver acceptable results within a rather narrow band of color temperatures. It is worth noting that the range of acceptable color with tungsten film is far smaller than when using daylight-balanced film under its designated light sources.

  • There are separate films made to be used with 3200K and with 3400K.

  • Only one group of films is necessary to cover the entire daylight spectrum from about 5000K to over 10,000K.

  • Although we have poor color memory, our psychological tolerance for certain colors that do not appear natural in a photo is very limited at best. Skin tones, blacks, whites, and grays are critical hues in this regard.

  • Not only are color films balanced for daylight or tungsten illumination, most individual films by brand are made to favor a particular cast from warm (red, orange, and yellow) through neutral, where colors appear more or less as we expect them to look, to the cool end of the spectrum (colors ranging from neutral to those with a bluish cast).

  • Film-makers go so far as to adjust color dye ratios for different film batches intended for sale in different parts of the world. Therefore, a film intended for the U.S. market might reflect a discernibly different color balance than the same brand and type sold in Europe or Asia.

What makes all this so difficult is the concept that acceptable color is a purely subjective decision on the part of each observer. For instance, what I consider pink, you might very well perceive as red. There are no objective, universal colors everyone agrees upon. There are only ones that a consensus points to and says, "These are colors that most agree fit the arbitrary names we have assigned to them." Thus, colors such as red, blue, green, or purple are only psychologically acceptable and by no means absolute.


There are methods and tools at our disposal to modify the color balance of film so that the images they produce exhibit acceptably natural colors. Filtration is the primary color-altering technique. It should be noted that even with perfect technical balance between film and light source, visible color imbalances still occur when lenses are coated with microscopically thin layers or coatings meant to contain aberrations, increase light transmission, or improve contrast. The effect of lens coatings on color balance and color rendition is variable even from lens to lens within the same brand lineup. Be aware that hues become contaminated by color reflected onto subjects from adjacent objects. Large areas of painted walls reflecting light on any photographic subject will invariably alter the overall color of the subject. If, for instance, one photograph a subject dressed in a red sweater standing near a yellow wall and the light from that wall reflects onto the subject, then the red sweater is likely to be recorded on film not as a pure red but as a somewhat orange, less intense hue.
 

More about film photography


Copyright © 2008-2017 BasicCameraPhotography.com. All Rights Reserved

BasicCameraPhotography.com is a participant in the Amazon Serivce LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com

All trademarks are the property of their respective owners.

Contact Us | Terms of Use | Privacy Policy