White Balance and Sekonic C-500

[Mark Paulson]

After reading the following post: http://luminous-landscape.com/forum/index....st&p=368682 , I was wondering if anyone out there has been using the Sekonic for white balancing their cameras. It would seem that on the Nikon D3 (maybe most cameras) you could dial in the temp in K and use the white balance function of the camera to adjust the green/magenta axis in the white balance fine adjustment to match the suggested color compensation value from the Sekonic. Anyone have any experience with doing this?

Thanks,
Mark

[digitaldog]

If you shoot raw, the WB is meaningless. The K values express a range, not an exact color. Every raw processor uses different math and processing to produce the same results. In a nutshell, I don’t see how this would be useful for raw shooters. Film had a very fixed rendering thus using such a meter, and assuming the recipe for compensation filters worked, that was then a useful instrument. Not so much today.

Now if you could get true spectral color info, and then somehow build an on the fly profile (DNG profile ideally for many), such an instrument could be quite useful.

[BJNY]

If you shoot raw, the WB is meaningless. The K values express a range, not an exact color. Every raw processor uses different math and processing to produce the same results. In a nutshell, I don’t see how this would be useful for raw shooters. Film had a very fixed rendering thus using such a meter, and assuming the recipe for compensation filters worked, that was then a useful instrument. Not so much today.

Now if you could get true spectral color info, and then somehow build an on the fly profile (DNG profile ideally for many), such an instrument could be quite useful.

Mark,

I think it's smart and very useful to dial in the Kelvin on the DSLR.
This way, at least the JPGs out of the camera are closer to neutral/desired balance.
The RAWs are also closer in case the client or retoucher doesn't use your same workflow
where the neutral balance setting resides in sidecar file as in C1 or Lightroom.

Also, when tethered there's an instant where the color could be [way] off/wrong
before the capture software applies the correction.
Why not avoid that dance altogether, and the inevitable question from the client or creative?

[Mark Paulson]

Mark,

I think it's smart and very useful to dial in the Kelvin on the DSLR.
This way, at least the JPGs out of the camera are closer to neutral/desired balance.
The RAWs are also closer in case the client or retoucher doesn't use your same workflow
where the neutral balance setting resides in sidecar file as in C1 or Lightroom.

Also, when tethered there's an instant where the color could be [way] off/wrong
before the capture software applies the correction.
Why not avoid that dance altogether, and the inevitable question from the client or creative?

Definitely a good point. What I'm still wondering if you can use the Green/Magenta axis to some how corresond to the CC value suggested by the C-500 when the  500 is set for digital.

[davidbicho]

Also very interested in CC to Tint-conversion. The Adobe Camera Raw-application has a Tint range from -150 to +150. This graph shows the CC from 380 to 700 (if I read it right)...


(http://en.wikipedia.org/wiki/Color_correction)

Shouldn't be to hard to Google, but I have failed so far...

Any one? CC to Tint?

[Iliah]

> If you shoot raw, the WB is meaningless.

Not meaningless if one uses filters or adjusts lights.

> Every raw processor uses different math and processing to produce the same results

Ahm... different math, same result... interesting perspective. There are two methods of white balance in use, one by Adobe and one by everyone else.

> I don’t see how this would be useful for raw shooters.

That is probably because you underestimate the implications of underexposure of the red channel in the daylight, or the blue channel under halogen lights.

[Iliah]

> This graph shows the CC from 380 to 700

Those are wavelengths, in nanometers (nm). Generally (approximately) it is considered that colour temperature is adjusted on "b" axis (blue to yellow) of Lab, but the tint is "a" axis (green to magenta). The scale of tint is not standardized, but one can use degrees, as in Lab space chromatic adaptation is basically rotation.