White Balance Lightroom vs 'in-cmaera' which is right?

[davidedric]

Well, I was only musing late at night. Sadly, at least on CiC, my physics is way better than my photography (which may not be saying much). , and I'd certainly bow to Manfred on anything photographic!

But for the record, it is the surface temperature that mostly determines the effective temperature. From Wikipedia:

The sun, with an effective temperature of approximately 5800 °C,[13] is an approximately black body with an emission spectrum peaked in the central, yellow-green part of the visible spectrum, but with significant power in the ultraviolet as well.

Hey ho. Dr D. E. Stott, MA (Oxon), PhD

[Manfred M]

Well, I was only musing late at night. Sadly, at least on CiC, my physics is way better than my photography (which may not be saying much). , and I'd certainly bow to Manfred on anything photographic!

But for the record, it is the surface temperature that mostly determines the effective temperature. From Wikipedia:



Hey ho. Dr D. E. Stott, MA (Oxon), PhD

Thanks Dave - I looked up the article, so Rayleigh scattering is responsible for the blue colour of the sky. So the lower colour temperatures that we see are related to the sun acting like black body radiator, but the higher colour temperatures (15,000 - 27,000K) result from interactions with the (mainly) nitrogren and oxygen atoms in the atmosphere. I remember that this effect caused the polarization of the light, but the colour temperature link, I hand't tweaked to. Thanks for this; makes sense.

Just looking at your name, one of my first year physics profs was a Dr Stott. That was a few decades ago though...

[revi]

And you should soonish have a perfect occasion to see the effect as snow scenes very often have two clearly visible zones with different colour temperatures: sunny parts will be around 5 000 K, shadowed parts (lighted by scattered light from the sky) appear blueish (the 15 000 to 27 000 K you mentioned), and there is no way to 'correct' for this through a white balance correction ('correct' in quotes as I'm not sure you should automatically remove this kind of colour difference)

[davidedric]

Hi Remco,

Damit. How many times have I looked at photographs and just not realised that was what I was seeing. Thanks for pointing it out.

Just a quick scan through my photos found this (NOT for C&C, please) which surely illustrates the point!

[Manfred M]

Don't remind me. The white stuff is coming all too soon, blue shadows and all. I don't do as much winter photography as I would like, simply because a lot of the places I like photographing are inaccessible. Trudging through a metre of snow is not my idea of a good time.

[davidedric]

I'm sure the rest of CiC are getting bored with this but I'd forgotten where you are. We're almost ten degrees north of you - and hardly ever see the stuff

[Manfred M]

Unfortunately, no mild temperatures here, courtesy of the Gulf Stream. Average January low temperatures is around -16C / 3F, and it can certainly dip well below that termperature. We get an average of around 2.4 m / 94 inches of snowfall in an average winter, but with a few thaws here and there, we don't often see that much on the ground at any one time. I think we get the most snow of any of the large Canadian cities.