Color temperature of light, measured in Kelvin: candlelight 1900K, tungsten 3200K, daylight 5600K. Corrected via CTB/CTO filters or continuously adjustable LED panels.
Technical Details
Standard values in film production: candlelight 1900K, tungsten-halogen light 3200K, daylight 5600K, overcast sky 6500K, blue hour 9000K. Modern LED panels offer continuous adjustment between 2700-6500K (Bi-Color) or 2700-10000K (Full-Color). Measurement is done via colorimeter or spectrometer, correction through CTB (Color Temperature Blue) and CTO (Color Temperature Orange) filters in increments from 1/8 to Full. Digital cameras work with white balance presets or manual Kelvin input, with modern sensors covering a usable range of 2500-10000K.
History & Development
Lord Kelvin defined the absolute temperature scale in 1848; its application in photography began around 1900 with Kodak's color film development. In 1935, the ASC first introduced standards for artificial light (3200K) and daylight (5600K). The introduction of colorimeters in the 1960s enabled precise measurements on set. Digital cameras revolutionized workflows from 2000 onwards through variable white balance settings and RAW recording, which allows for post-production color correction without quality loss.
Practical Application in Film
Christopher Nolan consciously uses 3200K tungsten in "The Dark Knight" (2008) for interiors against 5600K daylight for contrasts between Gotham and Batman. Emmanuel Lubezki varies between 2000K firelight and 9000K snow light in "The Revenant" (2015) for emotional temperature gradients. The standard workflow begins with colorimeter measurement, followed by filter or LED adjustment to uniform Kelvin values. Mixed lighting situations require gel filters: an 85 filter reduces daylight from 5600K to 3200K, CTB 201 increases tungsten from 3200K to 5600K.
Comparison & Alternatives
Temperature differs from tint (green-magenta shift) and color saturation. While analog filters correct physically, LED systems like ARRI SkyPanel or Aputure Nova offer continuous electronic adjustment. HSI LEDs (Hue-Saturation-Intensity) expand the spectrum beyond pure temperature correction to full color control. For budget productions, gel filters are preferred (cost: €2-5 per sheet), while high-end productions are dominated by programmable LED arrays (€15,000-€50,000 per unit) for time-efficient adjustments without filter changes.