Color temperature will shift about 80K per stop on any light light that uses voltage regulation for power control. Power is adjusted on these lights by sliders, knobs or buttons (like on a TV remote), and are pretty much standard on most mono lights like Alien Bees, White Lightning, Profoto, Elinchrom, Photogenic, etc.. Some mono lights and many pack and head systems will use capacitor switching for power control. This leads to no color shift, but less fine adjustments in power. Often, if the capacitor switching is used, it will be accompanied by voltage regulation for the finer control. This method is used in Zeus, some WLX series lights, and many others.
Einstein, however, is a different breed of light, using IGBT control. With this implementation, we can keep the fine power control and keep the color temperature constant.
However, with any light of any color, the color temperature will change based on the modifier. So, even with "perfect" color from the flash, the color temperature will still have potential for being different.
Changes in color temperature can be bad for catalog or very high end work where color accuracy is a must. But, color temperature is never consistent in real life, either.
Einsteins are great, and better than the Bees for more than just color consistency. However, the Bees are perfectly fine if proper white balancing steps are performed before and/or after the session.
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