Tone Balls™ are spherical gray scale reflectances that can improve the consistency of your color balances. Tone Balls™ have the advantage of allowing you to choose an area on the ball where you believe multiple light sources overlap, balancing the set, unlike flat balance reference targets whose balance can change depending on which source the reflectance reflects most.
Tone Balls™, because of their spherical shape, will always transition, from highlight to shadow on each ball. Measuring the difference between the highlight of the white ball to the highlight of the black ball using a reflection densitometer will deliver a 1.5D measurement, the same as the industry standard MacBeth Colorchecker™. But because each ball has a high to low transition, the total density range of the three balls will usually exceed the range of the scene, an important consideration when validating balance from highlight to shadow.
Tone Balls™ should be placed in the scene in a place where the main and fill lights overlap. Take a reading from the ball where you think the surface area mimics the scene with respect to camera angle and direction of the main light. Using a Color Coded Meter Capture adjust the aperture for the most important reflectance in the scene (not for the Tone Balls™). Check the Tone Balls™ for neutrality; if the RGB values individual reports differ by more than two units when read 0-100 or .2 unit when read 0-10, you’ll need to perform a new Setup>Balance. If you are using a Capture Curve with color correction embedded, turn off Capture Curve for the Setup>Balance then turn it back on after the balance procedure.