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Predictive color temperature model
I’m a student at Cornell University working on a design project aimed at creating a formulaic model to predict the color temperature of sunlight at any time and geographic location in the world. Our algorithms are well on their way and we need empirical data to verify our work. Thus, we are turning to the online photography communities to help us out!
We are asking people from all around the world to capture the color temperature of direct sunlight on a, preferably, sunny day by photographing (in RAW) a white balance card pointed toward the sun. From that image we’ll determine the color temperature and add it to our growing dataset. While we want pictures taken at any time of day and sun position, the white balance card musts be placed in direct sunlight.
Please send all photos (in any RAW format) to msf245@cornell.edu and include the following information in the email:
-Location (lat/long, if possible)
-Time
-Weather description (brief: cloudy, clear, overcast, a picture would work as well)
Attachment 1919
Predictive color temperature model
Interesting. 'White balance card' - there are many on the market, some true neutral or close to it, some far from it. Some people use index cards, and the bluing agents used in paper can lead to incorrect WB, especially in sunlight (due to fluorescence). Some people use gray cards, which while the luminance is QC'd to 18% gray (they're an exposure tool), the color is not QC'd and varies from lot to lot.
Would these variables affect your results, and if so, do you have a recommendation for an appropriate WB card?