Omegon Pro APO AP 71/490 – Compact Flat-Field Quadruplet Astrograph

The Omegon Pro APO AP 71/490 Quadruplet is a compact 71mm apochromatic refractor built around the needs of modern astrophotography. Its four-element ED optical system combines excellent colour correction with an integrated field corrector, giving you a flat imaging field without adding a separate field flattener to the optical train.

With a 490mm focal length, f/6.9 focal ratio and 44mm fully corrected field, this portable Pro APO is an excellent choice for capturing nebulae, star fields, open clusters and other wide-field deep-sky targets. The telescope is also capable of high-quality visual observation when required.

Four-Element ED Optics with Integrated Field Correction

At the heart of the Omegon Pro APO 71/490 is a sophisticated quadruplet ED optical system. Four optical elements work together to control chromatic aberration while producing the flat field required for high-quality astrophotography.

The integrated corrector provides a 44mm fully corrected imaging field. This simplifies the imaging train and removes the need to purchase, space and configure a separate field flattener.

All lens surfaces receive effective multi-coatings to reduce unwanted reflections and improve light transmission, helping produce crisp stars, strong contrast and naturally rendered colour.

Designed for Deep-Sky Astrophotography

The combination of 71mm aperture and 490mm focal length provides a highly useful field of view for deep-sky imaging. At f/6.9, the telescope offers a good balance between image scale, optical correction and portability.

It is particularly well suited to larger emission and reflection nebulae, open star clusters, rich Milky Way regions and wide-field compositions. The relatively short focal length also makes guiding less demanding than with a long focal-length imaging telescope.

• 71mm aperture
• 490mm focal length
• f/6.9 focal ratio
• Four-element quadruplet ED design
• Integrated field corrector
• 44mm fully corrected field
• Fully multi-coated optics
• Compact 373mm optical tube

2.5-Inch Precision Focuser

A capable astrograph needs a focuser that can accurately position modern imaging equipment. The Omegon 71/490 features a substantial 2.5-inch geared focuser with ball bearings for smooth, controlled movement.

The focuser can support accessories weighing up to approximately 4kg, making it suitable for cooled astronomy cameras and other imaging equipment. A 1:10 fine-focus reduction provides the precision required to reach critical focus.

Focus travel is 50mm, while a ring clamp provides secure attachment for compatible equipment.

Ready for Electronic Autofocusing

The focuser is compatible with several popular electronic focus motors without requiring additional adapters, making the telescope particularly attractive for automated astrophotography rigs.

• Omegon Pro Focus Motor Estia
• ZWO Electronic Automatic Focuser EAF N
• iOptron Electronic Automatic Focuser iEAF

Electronic focusing allows compatible astrophotography software to perform repeatable autofocus routines throughout an imaging session, helping compensate for focus changes caused by temperature variation.

360° Rotation for Precise Camera Framing

Finding the target is only part of creating a great astrophotograph. Camera orientation can be equally important, particularly when imaging elongated nebulae, galaxies or planning mosaics.

The 360° rotating focuser allows you to change camera orientation without rotating the optical tube or disturbing the telescope's position on the mount.

The 2-inch eyepiece adapter can also be removed to reveal an M64x0.75 female thread for compatible imaging configurations.

Compact, Lightweight and Portable

With an optical tube length of approximately 373mm and tube weight of around 3kg, the 71/490 is well suited to portable astrophotography.

The telescope includes tube rings and a Vixen-style dovetail rail for compatibility with a wide range of astronomy mounts. A Vixen/Sky-Watcher style finder base also provides a convenient mounting point for a finder or compact guidescope.

More Than an Imaging Telescope

Although optimised for astrophotography, the Omegon Pro APO 71/490 can also be used visually. Its colour-corrected refractor optics make it suitable for observing the Moon and planets as well as brighter nebulae, galaxies and star fields.

The compact optical tube can also be used for terrestrial and nature observation with suitable accessories.

Omegon Pro APO AP 71/490 Specifications

What's Included?

• Omegon Pro APO AP 71/490 Quadruplet OTA
• Integrated field corrector
• Tube clamps
• Vixen-style dovetail rail
• Dew shield
• Extension tubes
• 1.25-inch and 2-inch eyepiece adapters
• 45° 1.25-inch Amici prism
• 8mm eyepiece
• 20mm eyepiece

A Portable Flat-Field Astrograph for Modern Imaging

The Omegon Pro APO AP 71/490 Quadruplet brings together four-element ED optics, integrated field correction, a 44mm corrected field and precision focusing in a genuinely portable package.

For astrophotographers looking to build a compact deep-sky imaging rig without the complication of a separate field flattener, it offers an attractive combination of optical performance, portability and imaging-focused mechanics.

Available from Dark Clear Skies – UK astronomy equipment specialists.