Color Meter Weirdness

[Michael Panfeld]

Hi: I recently acquired a Sekonic C-500 color meter. I sent it off to have the sensor replaced and recalibrated (there was a recall of earlier serial #'s). I was excited to test it out against my trusty Milonta Color Meter II (which was also recently calibrated).

 

The Sekonic has two modes: film and digital. Its supposed to be some fancy new 4-sensor arrangement for use with digital camera sensors.

 

For the sun, tungsten and HMI light sources, the two meters tracked fairly well together. That is in measuring both color temp and green/magenta shifts. Didn't matter much if I had the Sekonic in film or digital mode for these three light sources.

 

However, for LED and fluoro sources, there were huge gaps when using the Sekonic's digital mode. I have an LED panel that measured 5600K and no green shift on the Sekonic in digital mode, but mesured huge green shifts and around 8,400K in the Sekonic film mode. This large discrepancy was pretty much confirmed with the Minolta, although the latter had slightly different readings.

 

1) So my first question is can someone explain a bit more about the "digital" mode on the Sekonic meter? I am looking for something beyond the company's literature and marketing materials (which are usually what is copied and pasted into blog reviews, etc).

 

2) Is this meter's digital mode (or some similarly-configured meter) how light manufacturers are getting away with claiming 5600K color temps and minimal green that turns out to not be true when you get the products? I'll note that I have returned LED fixtures and CFL & 55 watt fluoro lamps becuase they registered 8,000K and very green on the Minolta meter (which was before I got the Sekonic).

 

3) Finally, what do these readings, and the meters two modes mean for a cinematographer, a colorist, and someone just trying to buy and use lighting gear in today's fast-changing marketplace?

 

Thanks