ADC Correctors for Lunar and Planetary Observing
ADC correctors for sharper planetary images
When Jupiter, Saturn, Mars or Venus are low above the horizon, Earth’s atmosphere has a noticeable effect on visual observing and imaging. As the light passes through the atmosphere, different colours are refracted by different amounts. Bright planetary edges can then show coloured fringes and fine detail may look less clear.
An ADC (Atmospheric Dispersion Corrector) corrects this atmospheric dispersion. It brings the red, green and blue colour channels closer together so that planetary discs appear more natural and detailed. An ADC can make a decisive difference, especially in high-resolution planetary imaging with an astronomy camera. The improvement can often be seen directly during visual observing as well.
What an ADC can – and cannot – do
An ADC does not remove atmospheric turbulence and it cannot replace good seeing. It corrects the colour error caused by the atmosphere acting like a prism. When the general conditions are reasonably steady, this can reveal more detail and significantly reduce coloured fringes around bright objects. This is particularly helpful when a planet is not high in the sky.
How to use the corrector
The ADC is placed between the telescope and the eyepiece, or between the telescope and a planetary camera. For effective correction, it must be aligned according to the altitude of the target. The lower the planet is above the horizon, the stronger the atmospheric dispersion and the more important the correct adjustment. In an imaging setup, the connection, optical path length, clear aperture and available back focus should also match the existing accessories.
For lunar and planetary observing
ADC correctors are especially useful for high-resolution observing and imaging of the Moon and planets. On Jupiter, cloud bands and the Great Red Spot can appear clearer; on Mars, surface details can be easier to capture; and on Saturn, both the rings and the planetary disc benefit from cleaner colour rendition. Venus and other bright objects can also show fewer distracting colour fringes.
This category includes correctors such as the Omegon ADC Atmospheric Dispersion Corrector and other solutions for correcting atmospheric dispersion. If you are unsure which ADC suits your telescope, eyepiece or planetary camera, we will be happy to advise you.
