DNG Profiles - Color Chart Illuminant

[X-Re]

I've been using a set of Camera Calibration adjustments determined by Thomas Fors' script, like a lot of folks. I understand that I can continue to use the old profile for my cameras in LR 2.0, and the calibration settings I've already got will work fine with those profiles.

If I were to move to the new beta DNG profiles, and wanted to normalize the profiles to my camera via the color chart option... how accurate do the illuminant color temperatures need to be in order to take advantage of a dual illuminant profile? I don't have a color meter, unfortunately  If I were to, say, illuminate a chart evenly using strobes (which are really closer to 5500-5800), and then use the modeling lights on the strobes (tungsten, but unsure of exact temp), is that going to be close enough into the ballpark to be usable?

Another way of putting it, I guess, is how close to the specified illuminant temps is close enough? Is it hyper-critical, or is there some "fudgeability"

[madmanchan]

For daylight, there's a lot of leeway. So you what you're trying to do should be fine.

For tungsten, very little room to fudge. A standard household incandescent should be close enough.

[X-Re]

The modeling lights on my strobes actually are normal incandescent bulbs, so...

I posted this on the Adobe forum, too - if I hear anything different, I'll post it back here...

[madmanchan]

Well a normal household bulb is about 2850 K and spectrally very close to illuminant A. I very much doubt that your modeling strobes are like this if they're in the 5k to 6k range.

BTW, if you're shooting under a fixed condition, which it seems like you're trying to do, then you're better off just using Tutorial 5 of the PE documentation and creating a single-illuminant profile. (You wouldn't gain anything in this case by using dual-illuminant profile.)

[X-Re]

Well a normal household bulb is about 2850 K and spectrally very close to illuminant A. I very much doubt that your modeling strobes are like this if they're in the 5k to 6k range.

     The STROBE is 5k to 6k. The MODELING LIGHT is a normal household 100W light bulb.  http://alienbees.com/b800.html - I can switch from one to the other simply by turning off the Pocket Wizard on my camera, switch to Av mode on the camera, and then expose for the modeling light. Generally, it has the same light coverage as the strobe, just not as bright (and obviously a different color temperature).

BTW, if you're shooting under a fixed condition, which it seems like you're trying to do, then you're better off just using Tutorial 5 of the PE documentation and creating a single-illuminant profile. (You wouldn't gain anything in this case by using dual-illuminant profile.)
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     I'm not shooting in fixed conditions - nor am I trying to build a profile for a fixed condition. Tutorial 5 would obviously be the right answer for that. I'm interested in having one profile that I can use for the vast majority of situations - similar to how the previous (ie, currently non-beta) profiles worked w/ tweaking via Camera Calibration.