Omegon Pro APO AP 66/400 ED Apochromatic Refractor
The Omegon Pro APO AP 66/400 ED is a compact, high-quality apochromatic refractor designed for advanced visual observers, astrophotographers and nature enthusiasts who want excellent optical performance in a highly portable package.
With a 66mm aperture, 400mm focal length and f/6.1 focal ratio, this compact ED doublet is particularly well suited to wide-field astronomy, travel imaging and terrestrial observation.
A new improved Power Linear focuser combines the smooth action of a Crayford design with an additional rack-and-pinion guide rail, providing the rigidity and fine control required for cameras, larger eyepieces and high-magnification observing.
Compact 66mm ED Apochromatic Optics
The telescope uses a 66mm doublet ED objective designed to provide excellent colour correction and high image contrast.
Compared with a conventional achromatic refractor, the ED optical system reduces visible chromatic aberration, helping stars, planets and terrestrial subjects appear cleaner and more naturally coloured.
The manufacturer specifically positions the 66/400 ED APO as a high-quality compact instrument capable of maintaining very good colour correction even at magnifications around 100x.
400mm Focal Length for Wide-Field Astronomy
The 400mm focal length gives the telescope a relatively wide field of view, making it particularly useful for larger star fields, open clusters, brighter nebulae and other extended celestial targets.
At f/6.1, the Pro APO 66/400 is also well suited to astrophotography where a compact, relatively fast refractor can be advantageous.
The supplied specifications give a resolving capacity of 1.74 arcseconds, limiting magnitude of 10.9, light-gathering capacity of 90 and maximum useful magnification of 130x.
Power Linear Focuser with 1:10 Fine Focus
The improved Power Linear focuser is based on the Crayford principle but also incorporates a rack-and-pinion guide rail.
This hybrid approach is designed to provide both smooth focusing and increased mechanical stability when supporting heavier accessories such as cameras, diagonal mirrors or larger eyepieces.
A 1:10 fine-focus reduction allows very small adjustments when critical focus is required, particularly useful for astrophotography and high-magnification observing.
The focuser accepts 2-inch accessories, and the specification also confirms that the focuser is rotatable.
Suitable for Astrophotography
The combination of compact size, ED optics, 400mm focal length and precision focuser makes the Omegon 66/400 particularly suitable for portable astrophotography.
Its short focal length is useful for imaging larger targets and star fields, while the 1:10 fine focuser provides the control needed when reaching critical camera focus.
The formal specification rates the telescope as very good for astrophotography.
Visual Astronomy
Despite its compact dimensions, the Pro APO 66/400 can also provide rewarding visual observations.
The Moon and brighter planets are suitable targets, while the relatively wide field of view makes the telescope particularly enjoyable for scanning rich star fields, open clusters and larger deep-sky objects.
A suitable diagonal and eyepiece are required for visual observing and are not listed as included with this OTA.
Nature Observation and Telephoto Use
The compact ED refractor can also be used for terrestrial nature observation. Fine details in wildlife and distant landscapes benefit from the colour correction and contrast of the ED objective.
The 400mm focal length also allows the optical tube to function as a telephoto optical system when connected to suitable photographic equipment.
A 1/4-inch photographic connection allows the telescope to be fitted to compatible photo tripods, making it useful as a lightweight spotting or photography instrument when travelling.