Gearbox 0.7x FRA400/500

Askar F3.9 0.7x Full-Frame gearbox for FRA400 - Specifications and features

Le réducteur Askar F3.9 0.7x est conçu pour optimiser les performances de l’astrographe FRA400, en réduisant sa longueur focale d’origine de 400 mm tout en abaissant le rapport focal pour des expositions plus courtes et un champ de vision plus large. Ce modèle est parfaitement compatible avec les capteurs full-frame, permettant une couverture d’image étendue sans vignettage et répondant aux exigences de la plupart des astrophotographes en ciel profond.

Caractéristiques du réducteur Askar F3.9 0.7x

• Focal ratio reduction : The 0.7x reduction factor reduces the focal ratio from f/5.6 to f/3.9, increasing brightness and speed for capturing celestial objects with shorter exposures.
• Reduced focal length : The focal length is shortened to 280 mm, ideal for fast capture and a wide field of view, especially for diffuse objects such as nebulae and star clusters.
• Back focus : The rear focal length is a standard 55 mm, ensuring compatibility with a wide range of accessories and astrophotography cameras.
• Full-frame compatibility : This reducer is optimized for full-frame sensors, offering even coverage and vignetting-free images.

Dimensions and technical design

• Outside diameter : 72 mm, offering a robust and stable construction for astrophotography configurations.
• Total length : 63 mm, with a compact design that facilitates mounting on FRA400 systems.
• Front thread : M61*1, providing a stable and secure connection to the FRA400 astrograph.
• Rear thread : M48*0.75, designed to accommodate 2" filters directly, making filter installation quick and easy for users.

Benefits for astrophotographers

By reducing exposure time and increasing field of view, this reducer is ideal for astrophotographers wishing to capture high-quality deep-sky images. The ability to add 2" filters via the built-in M48*0.75 thread facilitates observations of nebulae and other celestial objects requiring specialized filters.