Sevunscope Advanced 250/1250

The large-aperture modular telescope, scalable and designed to go even further

The Sevunscope Advanced 250 f/5 is a configuration oriented toward longer focal lengths, designed for demanding astronomers who want to combine large aperture with increased comfort at high magnifications, while benefiting from the modularity inherent to the Sevun system. With a 1250 mm focal length, this model offers excellent exploration capabilities for planetary, lunar, and bright deep-sky observation within an advanced mechanical platform.

The idea behind the Advanced platform

Instead of enclosing the optics in a sheet-metal tube, we developed an open platform made of aeronautical-grade aluminum incorporating a telescopic mechanism. This architecture makes it possible to extend the platform to accommodate extended focal lengths, while ensuring a high level of mechanical rigidity. The platform provides the structure, while the modules carry the optics.

What this changes in the field

Controlled transport : The telescope remains fully dismountable and transportable, despite a more substantial structure linked to the telescopic mechanism. This deliberate compromise makes it possible to access long focal lengths without the constraints of a bulky tube.

Thermal equilibrium : The open structure allows the mirrors to reach thermal equilibrium naturally and quickly, limiting internal turbulence and promoting stable images at high magnifications.

Durable design : The use of aluminum combined with high-performance Nylon components (SLS 3D printing) guarantees a rigid and long-lasting instrument. Each unit is assembled and inspected by hand in our workshop. The mechanical structure is guaranteed for life.

A reliable optical system (GSO)

The 250 f/5 configuration at 1250 mm combines the light-gathering power of a large aperture with an optimal compromise for detailed planetary observation while remaining highly capable on deep-sky targets. Equipped with a 62 mm secondary mirror and a 2" rack-and-pinion focuser (with 1.25" adapter), it ensures generous field coverage and excellent stability for imaging trains.

An investment for your lifetime as an astronomer

The key strength of the Sevun system lies in its modularity. As your practice evolves, so does your instrument. With the Advanced platform, you retain your mechanical base and can evolve your optical configuration toward other focal lengths or apertures without calling your initial investment into question.

Technical Specifications

Magnification capabilities

Useful minimum : 35×
Resolving : 250×
Recommended maximum : 500×

Package contents

The instrument is delivered complete, ready for use on your mount :

Advanced platform : Aluminum structure with integrated telescopic mechanism (6.8 kg).
250 / 1250 optical kit : Primary and secondary modules.
Light protection : Shroud and six pultruded carbon support rods.
Focusing system : 2" rack-and-pinion focuser (with 1.25" reducer).
Included accessories : 6×30 illuminated finder, collimation laser.
UWA 68° eyepiece pair : 9 mm and 20 mm for full immersion from the first night.

System scalability

The Advanced platform is designed to accompany your progression. The chassis remains the same; only the optics evolve. For reference, here is the total weight (ready to use) :

150 mm configuration : 10.5 kg
200 mm configuration : 12.1 kg
250 mm configuration : 15.6 kg