ZWO Atmospheric Dispersion CorrectorZWO ADC is voted as HOT SKY PRODUCT 2017 by SKY&TELESCOPE magazine! ZWO Atmospheric Dispersion Corrector is used to reduce the effect of atmospheric dispersion on lunar and planetary images. The prisms are the center of the ADC Material: H K9L(Schott BK7) Surface Accuracy: 10@632. 8nm Deviation Angle: 2 Manufactured with a UV friendly AR coating Martin Lewis tells you what an ADC is and why do we need it? How to use it? Here is a review of ZWOs ADC by