revhen Loc: By the beautiful Hudson

It's all a function of motion. The faster things (electrons, molecules, photons, etc.) move, the hotter the temperature. Absolute zero (0 Kelvin) is the stopping of all motion. There's a large statue of Lord Kelvin in front of a park in Belfast, Northern Ireland.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Artistic license is not how I would characterize an observable and scientifically proven physical fact.

khildy Loc: Brownsburg, IN

Wow Gene, excellent interpretation!

jdmiles Loc: Texas

Slightly different approach here. The adjustments are based on LAB. The A channel curve swings from green to magenta. The B channel curve swings from blue to yellow. When you look at the image and it needs more yellow move that slider in the yellow direction. If the image needs more magenta move the slider closer to magenta.

wdross Loc: Castle Rock, Colorado

Relative terms. Kelvin temperature is based off a black body's heat radiation. 2000K (red) is cooler than 3800 (yellow). 3800K (yellow) is cooler than 5500K (white sunlight). 5500K (white sunlight) is cooler than 10,000K (even whiter white). As a black body heats up, it is mostly infra-red being radiated (felt but sometimes not even visible). As the black body heats up further, more infra-red some visible. As it heats up even further, even more infra-red, more visible, and some ultraviolet. Eventually the "blue" ultraviolet end of the scale out grows the "red" end of the scale. This is, unfortunately, about as simple it can be explained.

In the case you cite, 3800K is either a cool color or a warm color compared to 2000K or 5500K.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

Although this dial, excerpted from an old Kodad Professional Data Book and pertained to film usage, shows the colour temperature of many typical light sources. This kind of dial was handy in the film era because each colour film was balanced for a specific colour temperature and would require corrective filtration when there was a differential between the film's specification and the actual Kelvin temperature of the light source. There were other special filter combinations for light sources such as fluorescent and sodium or mercury vapour lamps that have discontinuous spectrums. There were conversion filters to enable the use of daylight films in tungsten lighting and vice versa.

Nowadays, in digital photography, the camera's white balance adjustment and auto-white balance enablement totally preclude additional filtration for colour correction. There are pre-sets and manual (custom) adjustments.

Although all light sources do not necessarily entail heating up a back body such as a tungsten filliment, Kelvin temperature is assigned to all kinds of light sources, daylight at different times of day and various weather, conditions and electronic flash which approximates daylight but is generated by ionizing gas in a flash tube.

The higher the number the cooler the light- the lower the warmer in actual colour rendition in the image.

Ostensibly, the most accurate colour rendition is obtained when the light source and white balance are perfectly matched. Aside from serious colour shifts, there is a useful range of latitude in that the photograher can opt for a warmer or cooler rendition as per taste and mood.

You can make these creative adjustments while shooting by adjusting the white balance or simply by going for a preset approximate balance (daylight, flash tungsten, etc., and tweak the colour values in post-processing.

Even some LED lamps have specific Kelvin ratings so you can pick from warm, neutral or colder light in fixtures and table lamps.

Quixdraw Loc: x

Dam' I must be old! I still have most of that set of books, and they come in handy on occasion. Days of yore when Kodak nearly ruled.

wdross Loc: Castle Rock, Colorado

I have a few too and I agree that they do come in handy from time to time.