C1's three White Balance Tools

[nilo]

The white balance tool lets you simply, pick on the image. But there is also the Auto function and the Auto mode (from the "Mode" drop down list). Each will yield very different results, in temp and tint (I am talking about RAW from a 5d2, with generic C1 ICC Profile and standard film curve, tethered studio portraits with and without strobes, just natural north light).

I am not satisfied with the different X-rite gray cards, they all give me too warm and reddish results. the "digital gray Kard" is not better, and Expo-disc is useless for this. Also, depending on where on the card you click, it gives radically different results. Question #1 is there serious comparison/tests available for gray cards.

The closest I can get (comparing a carefully calibrated screen and a print to reality) is by using the CROP tool to select the most of the gray card and than use the Auto "Mode". My second question is what do you do to get correct white balance with c1?

thank you

kind regards

nino

[Jack Varney]

I use a whibal card. If the white card is not blown out (i.e. no 255 values for either R,G or B) I use it or the light gray card. If the result is not satisfactory I adjust the white balance slider.

[nilo]

I use a whibal card. If the white card is not blown out (i.e. no 255 values for either R,G or B) I use it or the light gray card. If the result is not satisfactory I adjust the white balance slider.

that's exactly what I do, and I suspect that's what most of us do. Only did you notice big differences depending on where you click? I get quite noticeable differences.

[Jack Varney]

Assuming even illumination on the card, I get very close readings from anywhere on the card (within 25 to 50 K.). If the white card is blown out I use the light gray one.

[nilo]

Thank you jack for your replies.

In my experience it varies a bit more, and usually the result is not quite neutral to my eyes. Most of the times I find it a bit red. Evidently, I would not use any neutral result as is in most of the cases, especially not when I do portraits, which is what we do here. But I like to have a visual reference.

As I did not get so many answers, I reposted this question in the equipment section of the LL-forum (http://www.luminous-landscape.com/forum/index.php?topic=47189.0). Bart van der Wolf suggested BabelColor's white target to me. I'm very pleased by the results I got after the first day. What a difference!

regards
nino