The ZWO Atmospheric Dispersion Corrector is used to reduce the effect of atmospheric dispersion on lunar and planetary images. When imaging objects lower in the sky, the various wavelengths of light are dispersed into a spectrum by the effect of the atmosphere. This can degrade image quality substantially. The ADC uses rotating prism to counteract the effect of atmospheric dispersion, resulting in much sharper images. The prisms can be tuned to eliminate dispersion based on the current altitude in the sky of the target.
The ZWO ADC uses high quality prisms made from H-K9L(Schott BK7 equivalent) glass. The surface accuracy of the prisms is λfirstname.lastname@example.org. The prisms use a deviation angle of 2°.