CHF 1'619
In stock with supplier
L'Askar 131F Flat-Field is a large-diameter apochromatic refractor designed for demanding astrophotographers looking for advanced deep-sky performance. With its 131 mm, its focal length of 983 mm and its focal ratio of f/7.5, It offers an ideal combination of resolution, optical correction and Full Frame compatibility.
Thanks to its design self-correcting APO quadruplet, Askar 131F delivers fine, homogeneous stars across the entire field, without the need for additional flatteners or complex backfocus calculations. This approach considerably simplifies set-up while guaranteeing professional image quality.
The Askar 131F was developed for astronomers wishing to capture deep-sky objects with greater detail and resolution than with more compact scopes.
With a focal length of almost 1 metre, it provides particularly good sampling for :
The image circle of 44 mm provides native compatibility with Full Frame sensors, while maintaining excellent optical performance right down to the corners.
The optical system is based on a formula quadruplet APO air-spaced including :
This design effectively reduces chromatic aberration and improves overall image contrast.
The tube also incorporates optimized internal diaphragms to limit stray reflections and maximize the quality of the photographic field.
The built-in corrector makes it extremely easy to use:
The Askar 131F is supplied with several photographic adapters for excellent compatibility with modern equipment:
This compatibility facilitates integration with :
The mechanical design limits bending and promotes precise optical alignment, essential for modern large-format sensors.
Askar 131F is equipped with a sturdy eyepiece holder 3-inch Rack & Pinion, designed to support heavy light trains while maintaining excellent stability.
This focuser includes :
This design facilitates the extremely precise focusing required for high-resolution astrophotography.
The Askar 131F benefits from top-of-the-range CNC manufacturing with a particularly meticulous finish. The tube retains the elegant visual identity of the F series, with its blue and white finish.
The retractable mist guard improves transportability despite the instrument's large diameter.
The bezel also includes :
This configuration allows easy installation of :
With its 131 mm diameter and 983 mm focal length, the Askar 131F is a truly advanced astrophotography platform capable of accompanying high-end setups.
It is ideal for users who want to :
| Features | Value |
|---|---|
| Optical type | Quadruplet APO air-spaced with ED glass |
| Opening | 131 mm |
| Focal length | 983 mm |
| Focus report | f/7.5 |
| Image circle | 44 mm Full Frame |
| Field corrector | Integrated |
| Lens holder | 3″ Rack & Pinion double speed |
| Gearbox | 1:10 |
| Rotation | 360° graduated |
| Focuser stroke | 30 mm |
| Minimum length | 878 mm |
| Maximum length | 1026 mm |
| Net weight | 7.9 kg |
| Weight with collars and dovetail | 9.4 kg |
| Rear threads | M78, M54, M48 |
| Sensor compatibility | Up to Full Frame |
| Dovetail | Losmandy 300 mm |
| Adapters included | M48x0.75, M54x0.75, 2″ filter thread |
The Askar 131F is a particularly interesting solution for astrophotographers looking for a high-performance Full Frame refractor with greater resolution and light-gathering capacity.
Its modern optical formula, integrated corrector, robust mechanics and advanced compatibility make it an ideal platform for serious astrophotographic setups.
Whether you're photographing detailed galaxies, complex nebulae or building a durable, scalable imaging setup, the Askar 131F is an extremely consistent, high-performance telescope.
