FS7: Changeing color temp in 5 minutes

P

Publimix

Veteran
I can't delete this post which is a pity, reading at your own risk.

Today we had a cloudy day in the Netherlands, one minute sunny, and after a blink-of-an-eye, cloudy.

In five minutes I made 16 'white balances'

- one official white-balance card ('digital white balance' according the manufacturer, what that means is not sure, on or off?)
- one sheet of white plastic
- one sheet of copying paper (staples 80 gr/m2)
- one sheet of 120 gr/m2 luxury printing paper.


Here are the results:
[TABLE="width: 500"]
[TR]
[TD]'digital'[/TD]
[TD]cheap copy[/TD]
[TD]plastic[/TD]
[TD]luxe print[/TD]
[/TR]
[TR]
[TD]6400[/TD]
[TD]7100[/TD]
[TD]6400[/TD]
[TD]7500[/TD]
[/TR]
[TR]
[TD]6900[/TD]
[TD]7400[/TD]
[TD]6800[/TD]
[TD]8100[/TD]
[/TR]
[TR]
[TD]6600[/TD]
[TD]7000[/TD]
[TD]6600[/TD]
[TD]8000
[/TD]
[/TR]
[TR]
[TD]6500[/TD]
[TD]6900
[/TD]
[TD]6500[/TD]
[TD]7800[/TD]
[/TR]
[/TABLE]

One can say that the difference in colour-temperature can change about 600K, within a few minutes, the 'digital' sheet max 500K, the cheap copy 500K, plastic sheet 400K, luxe print 600K.

Normally I use only one sheet, the 'digital' one I bought, but even then the colour temperature fluctuated. (While it didn't fluctuate much on-the-eye).

The fluctuation on a windy, cloudy day, is about 9,2%, so there will be an error-margin of (at least) 9,2%.
 
Last edited:
I'm not really sure what you're testing here. What are you trying to determine? That sunlight and clouds shift white balance? That's something that's well known, that shaded areas are more blue. This is the reason why many DSLRs have a "shade" white balance preset.

But maybe I'm missing something here.
 
Yes you are right, the test was for fun to compare different white materials. What surprised me was not the shift but the speed and the percentage (which in this case was barely noticeable by the naked eye).

Next test: how to expose exactly 62% white zebra in slog3 when the light changes so fast. Exploiting the limits of the camera and the operator :-)
 
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