ZWO ADC (Atmospheric Dispersion Corrector) - T2 and 1.25" connection

When light from stars passes through the Earth's atmosphere, it is refracted into the colors. This phenomenon is called atmospheric dispersion. This operation results in that the light is split into its components, similar to a prism. This leads to some unpleasant effects, where eg Planets can be seen with a blue upper edge and a lower edge of red in the telescope.

To counter this you need such a corrector system.

Used for this purpose prisms which refract the incident light so that the previously split colors are combined again.