X-Rite White Balance Card vs Passport White Balance Card
Hello, ... Anyone have the X-Rite White Balance Card ( mini or full size) and perhaps the Color Checker Passport also? ...
If you do ... What color are they ?
Reason I ask is ... the Passport White Balance card is "greyish" while the cards themselves are white (overly white).
Why the difference? ... Should a white balance card be "greyish" or "white" ?
Thanks in advance
Visit my Nikonians gallery.
Visit my Flickr page.
#1. "RE: X-Rite White Balance Card vs Passport White Balance Card" | In response to Reply # 0Fovea Nikonian since 26th Sep 2002Tue 31-Jan-12 12:06 PM
Welcome to Nikonians!
I have the whibal white balance gray card and the colorchecker passport that came with the i1Profiler
I have never used a white, X-Rite white balance card; therefore I cannot comment about it, but the passport which I have and rarely use is a 24 colour target designed to be used with the x-rite software.
Now to your main question....
>>Should a white balance card be "greyish" or "white" ?
The short answer is, it really doesn't matter as long as it is NEUTRAL.
The only function of a white balance card is to provide a reference point to the software to judge the colour temperature of the light.
A neutral surface, meaning a surface designed to reflect equal amounts of red green and blue from a NEUTRAL light source is ideal for this purpose because.
1. it can be used as a generic target on multiple programs without depending on a particular sophisticated software to achieve white balance
2. Sensitivity to changes in light amount would be minimal with a neutral target.
If you put red gels on all your lights and make an image of a white balance card, and then click on the image of the card in your software to correct colour balance; the software, knowing this surface is designed to reflect equal amounts of red green and blue light from a NEUTRAL light source, cuts the extra red your gels have added and equalize the RGB components and makes card look gray/white again. By doing that it makes the entire scene appear to have been photographed with a neutral light source
Therefore a neutral grey (equal rgb values) or a white card that can reflect equal amounts of RGB components can be used as a white balance card.
#2. "RE: X-Rite White Balance Card vs Passport White Balance Card" | In response to Reply # 0walkerr Nikonian since 05th May 2002Tue 31-Jan-12 12:15 PM | edited Tue 31-Jan-12 12:16 PM by walkerr
If you're placing the card in a shot and then adjusting the white balance later in a raw processor, you're better off with a grey card. A white card is more likely to be either close to the high end of your camera's dynamic range or beyond it. You can work around that, but a grey card is less likely to have this problem. My vote would be for a grey card, whether a Passport or a Whibal. Either of those works well as a grey card. The Passport will also enable you to generate custom color profiles for use in Adobe raw converters or create slightly warm or cool white balance settings. It costs more, though.