White Balance Meter

White Balance Meter Reading - when are they going to come out one or

embedded inside a cameara?

It would be nice that I have a dial knob on my camera for my white-

balance, which range from 1000K to 10000K, and a white balance meter

tell me when they are correct... Just like light meter reading. The

Auto WB, cloud WB, etc tell me nothing about the current temperature

in K or if my white balance reading is correct.

 

It is nice that I can use my Custom WB, but it is a pain in a butt

everytime I have to custom it whenever changing indoor to outdoor

and vice versa or when lighting change. It would be nice to just

dial a knob for WB and set to certain temperature and you done or a

spot meter for White Balance or Current Temperature reading.

 

I guess I have to wait another 5 Years for it.

Hi Kelvin, I'm not sure when a camera will have it, but a hand-held color temperature meter (measured in "kelvins"!) is very expensive - much moreso than a light meter. If your camera supports it, you can shoot RAW and adjust your WB settings there, after the shot. Good luck!

wb meter @ $700 or $900 (B/H).

Kelvin,

 

Colour meters are available, as has already been explained. They are all incident meters - none of them are reflective. There are reflective devices (colourimeters, reflection densitometers) but they are normally used for measuring the colour properties of a surface, not the colour properties of a source of illumination.

 

The colour of light cannot be described solely by a colour temperature (call it yellow-blue balance) - though that works for light from incandescent sources. If you also want to be able to cope with fluorescent sources, you need a second variable - call it the green-magenta balance. So to take the reading from a colour meter and apply it to your camera you would need either two adjustments on the camera, or one adjustment for temperature and CC filters for the green-magenta balance.

 

Doing a manual white balance on a white, grey or coloured card isn't so bad in comparison.

 

There's a plentiful supply of Minolta Colormeter IIs on eBay for a couple of hundred US dollars, if you are interested.

 

Best, Helen

Wow, essentially the same question on on two different forums on the same day.

 

There's a big differnce between white balance and color temperature. Color temperature is a single quantity, expressed in Kelvin.

 

White balance is two (or possibly more, but usually two) quantities. It's usually expressed as gain of red and blue (relative to green, which is assumed to be "neutral" or without gain). Cameras don't compute a single color temperature when they do "preset" white balance or auto white balance, or even when you set the white balance to fluorescent. Instead, they use separate red and blue gains. This produces greater color accuracy than you can have with simple color temperature settings.

 

A Kelvin color temperature can be converted to a white balance setting (one number becomes two). But you can't always go the other way around. If your light source has a definite "color temperature", such as sunlight or incandescent light or flash, and you use a camera's "preset white balance" feature to get a white balance from a "white card" or "gray card" or ExpoDisc or "Pringles" lid, the red and blue gain the camera computes can probably be converted back into a color temperature (although no camera currently on the market does this).

 

But if the light source doesn't have a proper color temperature, like fluorescent light or sky light or light that's reflected off the painted walls of a room or filtered through curtains, then you cannot compute a color temperature from the camera's red and green compensation numbers.