Black and White Artzone- FilterZone- Color Temperature of light sources

Color Temperature of light sources

Filter Exposure Factor

Black and White Contrast control Filters

Conversion filters for color films

Light balancing filters

Neutral Density filters

Ultraviolet- Absorbing Filters

Infrared transmitting Filters

Color compensating filters

Safelight filters

Contrast Control-Printing Filters

Color Printing Filters

about Color Temperature and Light sources

**Standards of Luminous Intensity and**
**Their Color Temperatures**
Source	Color Temperature (Kelvin)
Standard British candle Hefner Harcourt pentane Acetylene Incandescentcarbon (4 watts/candle) Incandescent tungsten (1.25 watts/candle) Freezing point of platinum	1930 1880 1920 2415 2080 2400 2042

**Selected Practical Sources of Illumination and Their Color Temperatures**
Source	Color Temperature (Kelvin)	Mired Value
Sunlight (mean noon) Skylight Photographic.Daylight Crater of carbon arc (ordinary hard-cored) White-flame carbon arc Flashcube, magicube or flipflash High-intensity carbon arc (sun arc) Clear zirconium wire-filled flash Clear aluminum wire-filled flash 500-watt (photoflood) approx. 34.0 lumens/watt 500-watt (3200 K photographic) approx 27.0 lumens/watt 200-watt (general service) approx 20.0 lumens/watt 100-watt (general service) approx 17.5 lumens/watt 75-watt (general service) approx 15.4 lumens/watt 40-watt (general service) approx 11.8 lumens/watt	5400 12000 to 18000 5500 4000 5000 4950 5500 4200 3800 3400 3200 2980 2900 2820 2650	185 83 to 56 182 250 200 202 182 238 263 294 312 336 345 353 377

Mired System for light conversion

                                    1.000.000
Mired value=   -------------------------------
                          color temperature in kelvin

**`Mired Values of Color Temperatures from 2000-6900 K`**
`K`	`0`	`100`	`200`	`300`	`400`	`500`	`600`	`700`	`800`	`900`
`2000` `3000` `4000` `5000` `6000`	`500` `333` `250` `200` `167`	`476` `323` `244` `196` `164`	`455` `312` `238` `192` `161`	`435` `303` `233` `189` `159`	`417` `294` `227` `185` `156`	`400` `286` `222` `182` `154`	`385` `278` `217` `179` `152`	`370` `270` `213` `175` `149`	`357` `263` `208` `172` `147`	`345` `256` `204` `169` `145`

T₁ represent the color temperature of the original light source. represent the color temperature of the light through the filter.Using some filters, like Kodak light balancing filters, we can modify the effective color temperature. Giving to each filter a mired shift value, represented by the expression (1/T₂ - 1/T₁)*10⁶
either positive or negative, you can change the color temperature. Using yellowish filters, the mired value increases, having a positive mired shift value, resulting lower color temperature.Using bluish filters, the mired value decreases, having a negative mired sift value, resulting higher color temperature.
The above nomograph simplify to theory, showing the proper conversion filter. To find the requested filter (the mired shift value), place a straightedge on the points corresponding to the color temperature of the source, T_1,and the color temperature of the desired sourceT₂