ZWO 1.25" Atmospheric Dispersion Corrector for Planetary Observing and Imaging

Atmospheric dispersion is caused when light enters our atmosphere, naturally bending it and delivering the individual colors in the visible light spectrum at different angles.   Telescopes and cameras exaggerate this phenomenon making some colors more apparent than others which is often undesirable when viewing or capturing night sky images.  This is especially so when viewing or imaging bright objects like the Moon or planets, through heavy atmospheric conditions.  This cannot be avoided without the use of a corrective lens like the ZWO Atomospheric Dispersion Corrector, even if shooting in monochrome with LRGB filters you'll experience dispersion in the luminance frame.  

By employing a pair of prisms, the ZWO ADC can be manually adjusted to correct atmospheric dispersion until all colors in the spectrum are aligned to create white light at the focal plane.  Extend your viewing and imaging time by avoiding unwanted color fringing when objects are near the horizon!    Consisting of three components the corrective prism and adjusting levers are housed in the main body of the corrector.  The overlapping adjustment levers allow for a wide range of movement and a 1.25" barrel adapter on either end of the prism allow you to easily adapt to your telescope and camera with standard 1.25" adapters.  Optimized for use with high focal ratios, if you are working with a fast telescope, use a Barlow lens to extend the effective focal length.  

To ensure precision adjustments, there is a locking screw and scale marked on the body. Made to exacting standards, the H-K9L Schott BK7 prisms have a 2 degree deviation angle, produced to tenth wave accuracy.   With AR coatings on all optical surfaces, transmission is greater than 98%.