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I'm teaching PowerPoint 2010 and it's got some great new features. Unfortunately, one that I can't wrap my head around is the the new "Color Temperature" feature for pictures. I do understand color temperature in general (i.e. the lower the number, the "colder"/"oranger" - the higher the number, the "hotter"/"bluer"). The way PowerPoint implements it seems opposite from most other programs - like Photo Filter in Photoshop.

So I need to understand what this feature is in more detail so I can explain it to my students. Does anyone know?

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Maybe the difficulty is that 'warm colours' come from lower colour temperatures, and 'cool colours' come from higher colour temperatures? Ultimately, do your students need to understand this to achieve their objectives with PowerPoint? As long as they can use the control and see the results I'd have thought things were fine. You could maybe give them some pics which you've modified to look bad, and they have to correct them using the colour temperature control? –  Andy Jun 15 '10 at 14:44
    
@Emory Bell: How do you get that? Check the wikipedia link or search on "black body" and this is the "color temperature" I'm talking about. Is there another definition of "color temperature" out there that is different than this? If so, can you pass me some links? –  Otaku Jun 15 '10 at 14:50
    
@Emory Color temperature refers to the physical meaning here. A higher temperature means higher peak energy (see black body radiation) and thus higher frequency = lower wavelength = "bluer" –  Tobias Kienzler Jun 15 '10 at 14:54
    
@Otaku I think Emory is refering to the psychological association. Also your standard water-tap is (irritatingly, now that I think about it) labeled blue for cold and red for warm water... –  Tobias Kienzler Jun 15 '10 at 14:56
    
I apologize--my comment was misinformed and thus I have deleted it. –  Emory Bell Jun 15 '10 at 14:59
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1 Answer

Color temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, astrophysics, and other fields. The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of comparable hue to that light source. The temperature is conventionally stated in units of absolute temperature, kelvin (K). Color temperature is related to Planck's law and to Wien's displacement law. Higher color temperatures (5,000 K or more) are called cool colors (blueish white); lower color temperatures (2,700–3,000 K) are called warm colors (yellowish white through red).

  • 1,700 K Match flame
  • 1,850 K Candle flame
  • 2,700–3,300 K Incandescent light bulb
  • 3,350 K Studio "CP" light
  • 3,400 K Studio lamps, photofloods, etc.
  • 4,100 K Moonlight, xenon arc lamp
  • 5,000 K Horizon daylight
  • 5,500–6,000 K Typical daylight, electronic flash
  • 6,500 K Daylight, overcast
  • 9,300 K CRT screen

Note: These temperatures are merely characteristic; considerable variation may be present.


Thanks Wikipedia http://en.wikipedia.org/wiki/Color_temperature

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I think the way photoshop implements it is more in a perspective fashon (ie the picture LOOKS warm vrs. is warm on the kelvin scale) –  mjrider Jun 15 '10 at 15:20
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Thanks for the details, but what I'm looking for an explanation on the opposite. Why does PowerPoint 2010 do this backwards? Meaning the way PPT2KTen does it is that blue is a lower number and orange is a higher number (range between 1500 and 11500) in the "Color Tone -> Temperature" gauge. –  Otaku Jun 15 '10 at 15:41
    
oh...your right...its backwards...That is RELAY strange...I...don't think it is suppose to be that way... –  mjrider Jun 15 '10 at 15:42
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