@salomaorocha wrote:
I have a Canon 5D mark II and a 100mm Macro IS USM. I use the flash MT-24EX and MR-14EXII. To obtain a correct white balance (using neutral gray card) with the MT-24 flash I have to shoot with 5800K. When I use the MR-14EXII flash, and using the temperature setting for the white balance, I can only get the right balance to a 6900K temperature. Why is there a so big difference between these two flahses?
Color temperature is at best a synthetic approximation to reality, since it assumes an idiosyncratic frequency distribution in the light source (originally that of a heated iron bar). Any given light source is practically guaranteed to have a frequency distribution different from the presumed standard, and different light sources will vary in different ways. Moreover, the human eye is not uniformly sensitive to different frequencies. And most modern light sources radiate at some combination of discrete frequencies that can produce odd results when combined. The best you can hope for is that the combination at your disposal can be sensibly corrected to something that appears plausible to the eye. Sometimes that's difficult to achieve.
Bob
Philadelphia, Pennsylvania USA
