Doug Kerr
Well-known member
The ColorRight MAX is a combination of a white balance measurement diffuser and a reflective target. With respect to the latter functionality, about half the "target" area is said to very close to neutral, and is intended for normal white balance color correction control during raw image development (the target having been included in the actual shot or a calibration shot).
The other half is divided into six sectors with chromaticities that depart from neutral in the same general direction (blue-to-cyan) and by different amounts.
When developing a raw image file, by using one of these non-neutral sectors as the "white balance reference", we can force the color correction to not be a theoretically ideal one but rather one that gives an offset of all the chromaticities in the image from what they would be under a true white balance color correction, in the general direction of red-to-yellow and in any of six different amounts.
The object is to force skin tones to an arbitrary more red-to-yellow chromaticity that may be more artistic, more flattering, more pleasing, or more profitable that their rendering under theoretically ideal while balance color correction.
Of course, all other objects in the image will have their chromaticities shifted the same way, but the viewer is typically most sensitive to the chromaticity of skin and the incidental shifts are generally harmless.
We were interested to see what six specific "chromaticity offset vectors" the manufacturer had chosen for the ColorRight MAX's palette. We do not have a sample ColorRight MAX to measure, nor any data (authoritative or otherwise) on the reflective chromaticities of the six "offset" sectors.
So, as an interim step, we determined the chromaticity of those sectors as disclosed in the photographs of the unit on the manufacturer's Web page. In doing so, we assured that the "neutral" portion of the target was in fact close to chromatically neutral (it is supposed to be more neutral then Switzerland and lots more than God).
Here's the picture we used. You can see the sector numbering that is used for our results.
These might of course not be representative of actual typical product chromaticities.
In any case, based on those numbers (and remember, its been said that in this regard, numbers don't count anyway), we plotted the expected chromaticity offset to be produced by the use of each of the six target sectors on the familiar CIE du'dv' chromaticity chart. Here is the result:
To give some idea of "scale", very approximately, a chromaticity shift equal to one "tick" on this chart is about the smallest difference that can be observed in an A-B comparison.
Note that the offsets shown are not the departures of the six target sectors themselves from reflective neutrality, but rather the chromaticity offsets their use for reference would produce on the image (just the opposite in direction to the former).
Quite frankly, we feel that this is a rather peculiar distribution of available offsets (but of course we've looked at expensive palettes of face makeup and had the same feeling). I'm sure they were chosen through great thought and awareness of the needs of photographers.
The other half is divided into six sectors with chromaticities that depart from neutral in the same general direction (blue-to-cyan) and by different amounts.
When developing a raw image file, by using one of these non-neutral sectors as the "white balance reference", we can force the color correction to not be a theoretically ideal one but rather one that gives an offset of all the chromaticities in the image from what they would be under a true white balance color correction, in the general direction of red-to-yellow and in any of six different amounts.
The object is to force skin tones to an arbitrary more red-to-yellow chromaticity that may be more artistic, more flattering, more pleasing, or more profitable that their rendering under theoretically ideal while balance color correction.
Of course, all other objects in the image will have their chromaticities shifted the same way, but the viewer is typically most sensitive to the chromaticity of skin and the incidental shifts are generally harmless.
We were interested to see what six specific "chromaticity offset vectors" the manufacturer had chosen for the ColorRight MAX's palette. We do not have a sample ColorRight MAX to measure, nor any data (authoritative or otherwise) on the reflective chromaticities of the six "offset" sectors.
So, as an interim step, we determined the chromaticity of those sectors as disclosed in the photographs of the unit on the manufacturer's Web page. In doing so, we assured that the "neutral" portion of the target was in fact close to chromatically neutral (it is supposed to be more neutral then Switzerland and lots more than God).
Here's the picture we used. You can see the sector numbering that is used for our results.
These might of course not be representative of actual typical product chromaticities.
In any case, based on those numbers (and remember, its been said that in this regard, numbers don't count anyway), we plotted the expected chromaticity offset to be produced by the use of each of the six target sectors on the familiar CIE du'dv' chromaticity chart. Here is the result:
To give some idea of "scale", very approximately, a chromaticity shift equal to one "tick" on this chart is about the smallest difference that can be observed in an A-B comparison.
Note that the offsets shown are not the departures of the six target sectors themselves from reflective neutrality, but rather the chromaticity offsets their use for reference would produce on the image (just the opposite in direction to the former).
Quite frankly, we feel that this is a rather peculiar distribution of available offsets (but of course we've looked at expensive palettes of face makeup and had the same feeling). I'm sure they were chosen through great thought and awareness of the needs of photographers.
