Night Shots and Colour Temperature

[craigbowman]

I've been mucking about in post with the colour temperature on some footage I shot for some outdoor night scenes. Cooling things down to different extents in the top four and doing the opposite in the bottom two because of the fire. Does anyone know if there's an optimal target? (ie. I set the reference temp in some instances to 1700 degrees kelvin so the lighting in the shot would look a cooler blue). This project has been the first time I've had the chance to get my toe in the water on night setups.

 

[PhilJackson]

I believe moon light is roughly 4100K. Might be off by a few hundred though.

 

[craigbowman]

Yes moonlight is 4100 kelvin but the reason we perceive blue is still just a theory about rod and cone interaction and the physiology.

Here is a link to a paper on the subject. http://graphics.cs.ucf.edu/papers/jov.pdf

 

[David G. Smith]

Yes moonlight is 4100 kelvin but the reason we perceive blue is still just a theory based around rod and cone firing physiology when light falls below certain levels.

I thought as light levels fall, the image becomes more mono-chromatic, i.e. black&white. I have never thought that the deep blue color was a true representation of moon light, but that it has just become an accepted cinema convention.

 

[craigbowman]

I thought as light levels fall, the image becomes more mono-chromatic, i.e. black&white. I have never thought that the deep blue color was a true representation of moon light, but that it has just become an accepted cinema convention.

Yes, mechanically, as light levels fall the image does become more monochromatic. However, the adoption of blue for cinema wasn't just picked at random out of a hat. There is something in human physiology which causes most people to perceive blue. Its known as the Purkinje effect.

 

[David G. Smith]

Yes, mechanically, as light levels fall the image does become more monochromatic. However, the adoption of blue for cinema wasn't just picked at random out of a hat. There is something in human physiology which causes most people to perceive blue. Its known as the Purkinje effect.

That is cool. Must be an evolutionary adaptation for help in seeing in pre-dawn and post sunset twilight, as once the sunsets, or before it rises, the available light, reflected from the sky, is very blue.