Calibrating color meters

[Jayanth Mathavan]

Hi,

In my film school, we have three color meters. There are two Sekonic Prodigi Color C-500 and one Minolta Color Meter IIIF. But right now, all the three color meters are showing different color temperatures when measuring the same light source. The difference ranges around 300k to 500k from one color meter to another color meter. So am not sure which color meter is showing the correct color temperature. Can anyone please guide me on how to judge which the correctly working color meter. and also is there a way we can calibrate the color meter? please help.

 

Thanks and Regards

Jayanth

India

[Marcelo Ragone]

Hi Jayanth:

 

An absolute test of a color meter is using a black body. I never seen a real one, but I heard there are some at the meters factory. It may be others at some optics or physical department.

A more practical test is by using a naked, new, cinematography tungsten lamp. If the voltage is right the color temperature should be right. You may also verify it with a digital camera; (I guess) grey card should photograph grey using the tungsten white balance pre-set.

By the way, which color meter do you prefer, or consider best, Sekonic?, Minolta?

 

Thanks

Marcelo

Buenos Aires

Argentina