I have been exploring white point and white balance by taking a series of images of the sky from my flat window. The images are not inspiring at all, but it doesn’t matter. The process has got me to explore what I think white point and white balance are.
My initial thoughts were
The brightest part of the image was the white point.
When developing photos you can’t recover clipped highlights because when part of an image is maximum white 255, 255, 255 then there cannot be detail.
White balance is the colour shift in the scene based upon the tone of the white in the image.
I had no understanding of light and weather conditions affecting white balance.
I did know that I liked being outside just after it had been raining because everything was more vibrant.
I did know that overhead bright sunshine made everything duller and lose vibrancy.
Learning:- light is not the same. Cloudy conditions – diffused lighting.
Light has a colour temperature in relation to blackbody radiation. (Newton, Kirchhoff, Plank, Wien, Einstein) Manjit Kumar; 2008; Quantum – Einstein, Bour and the Great Debate About the Nature of Reality; Icon Books; London; p14 and Chapter 1.
Cooler temperatures have a longer wave length so light is redshifted, hotter temperatures have a shorter wavelength so light is blue shifted.
Bright over head sunshine – hotter temperature (of light in kelvin (5500), bluer light with less vibrancy.
Cooler sunset – red shifted light (3500 – 4000k) yellow to orange.
Cooler sunrise – redshifted light (3000 – 3500k)- red to yellow.
Slightly cloudy – (6500 – 8000k) greener
Cloudy – overcast – deep shade (9000-10000k) http://www.cambridgeincolour.com/tutorials/white-balance.htm (accessed on 28/06/2017)
As light changes then colour tone of light changes so colour tone of scene has more or less red, green, blue.
White balance is also affected by the green/magenta shift especially with artificial light.
Manjit Kumar; 2008; Quantum – Einstein, Bour and the Great Debate About the Nature of Reality; Icon Books; London; p14 and Chapter 1.