Optical tube Newton Astrograph ARTESKY ARTEC 250 EZ F/4.5 compatible with ASIAIR

Newton Astrograph ARTESKY ARTEC 250 EZ F/4.5 ASIAIR compatible astrograph optical tube

The ARTEC series introduces a modern and innovative approach to telescope manufacturing, considering the astrograph not as an isolated component, but as an integral part of a complex astrophotographic acquisition system.

The project, conceived by Stefano Seveso, founder of Artesky, and developed together with engineer Flavio Simeone, was launched in 2011. It was designed specifically for demanding astrophotographers looking for stable collimation, exceptional optical quality and consistent image performance.

Over the years, the ARTEC series has undergone continuous development and refinement, both in design and production, with a clear focus on adopting state-of-the-art engineering techniques.

The ARTEC 250 is a Newtonian astrograph with an aperture of 250 mm, manufactured entirely in Italy by skilled technicians. It is an excellent addition to the ARTEC range, offering a highly refined and robust instrument.

With a native focal ratio of f/4.0, the system incorporates a quartz parabolic primary mirror, coated with aluminum for a reflectivity of over 95%. The secondary mirror receives the same treatment.

Its generous dimensions make it ideal for fixed observatories or for expert astrophotographers on the move looking for dark skies and long-term stability. Thanks to its precise mechanics, collimation holds up better than typical Cassegrain systems of the same diameter.

Optical quality and coma correction

Each optical assembly is selected to ensure the overall accuracy of the telescope:

• Reflectivity > 95 %
• Correction of λ/8 or better
• Strehl's ratio ≥ 0.95

The quartz conical primary mirror ensures optimal thermal behavior, minimizing lateral shifts and optimizing cooling time.

The included 1.14x coma corrector provides a focal length of 1140 mm (f/4.56) and a fully illuminated 44 mm field, ideal for full-frame sensors.

Mechanical and cooling details

Three quiet 12V fans speed up the cooling of the mirror. All mounting screws are made of 316 stainless steel, hand-polished for corrosion resistance and attractive appearance.

Each unit is thoroughly tested prior to delivery to ensure compliance with Artesky's quality standards.

Precision mechanics and materials

Using advanced design software, each mechanical part is manufactured from CNC-milled 6061 aluminum and laser-cut components. The result is a rigid, stable, easy-to-use system that maintains collimation over long sessions.

All mechanical parts are made from lightweight aluminum, steel and bronze. The secondary support, laser-cut for maximum rigidity, ensures easy alignment. A special anodizing treatment protects against the weather.

High-performance optics: quartz mirrors, superior coatings

• Optical design: Classic Newtonian
• Primary mirror diameter: 255 mm (conical quartz)
• Secondary mirror diameter: 100 mm
• Native focal ratio: f/4.0 (f/4.56 with coma corrector)
• Focal length: 1,000 mm (1,140 mm with coma corrector)
• Coma corrector included: 1.14x, resulting in f/4.5
• Mirror material: High-quality quartz with >95% reflectivity
• Optical correction: λ/8 or better
• Strehl ratio: ≥ 0.95
• Linear obscuration: 30%
• Fully illuminated field: 44 m

The conical primary mirror ensures excellent thermal stability and eliminates lateral shifts. This design reduces thermal mass while maintaining mechanical rigidity, crucial for long exposure imaging.

100% solid carbon fiber tube

Chosen not only for its weight, but also for its structural rigidity and thermal stability, the carbon fiber tube is manufactured by an Italian company specializing in aerospace-grade materials.

It is autoclave-treated, with a matte finish on the outside and a blackened interior coating with anti-dust and anti-reflective coating. Its roughened interior reduces moisture retention.

Items included

• ARTEC 250EZ carbon astrograph, optimized for harmonic mounts
• Precision machined tubular rings and aluminum struts
• Dovetail bar Losmandy
• 3" Prodigy electronic microfocuser (compatible with ASIAIR)
• M54x0.75 thread R.O.A.S. system
• 4" optical train tilter
• 1.14x coma corrector
• Reinforced cardboard packaging

why choose the ARTEC 200EZ?

• Designed and manufactured entirely in Italy
• Premium quartz optics with high reflectivity and λ/8 correction
• Mechanical design optimized for thermal stability and rigidity
• ASIAIR compatible focuser and full modularity
• Lightweight yet rugged: ideal for harmonic mounts and portable imaging
• Each unit is individually tested and collimated by Artesky technicians

Technical Specifications

• 
  Optical assembly: Newtonian astrograph
• Diameter: 250 mm
• Primary mirror diameter: 255 mm
• Secondary mirror diameter: 100 mm
• Focal length: 1,000 mm - 1,140 mm with coma corrector 1.14x
• Focal Ratio: F/4.0 - F/4.56 with 1.14x Coma Corrector
• Mirror material: Quartz
• Linear obstruction: 30
• Illuminated field: 100 % 44 mm
• Dimensions: 921 L x 310 W x 480 H
• Weight: 19.7 kg
• Tube Material: High-end carbon fiber
• Mechanical material: 6061 aluminum

Optical tube Newton Astrograph ARTESKY ARTEC 250 EZ F/4.5 compatible with ASIAIR