Gearbox 0.7x FRA600

Askar 3" F3.9 0.7x Reducer for FRA600 - Optimize your Astrophotography

The Askar reducer 3 inches F3.9 0.7x is designed specifically for the FRA600 astrograph, optimizing its capabilities for astrophotography and visual observation. Featuring a 4-element optical design, this reducer reduces the focal ratio and increases the field of view, meeting the needs of astrophotographers looking for increased brightness and speed when capturing large-scale celestial objects. This model is compatible with full-frame sensors, ensuring full image coverage without vignetting.

Askar 3-inch F3.9 0.7x gearbox specifications

• Focal ratio reduction : The 0.7x reduction factor enables the focal ratio of the astrograph to be changed from f/5.6 to f/3.9, increasing brightness for shorter exposure times.
• Reduced focal length : The focal length is reduced to 420 mm, ideal for deep-sky shots and the observation of large stellar fields.
• Lens design : 4-element system optimized for sharp, aberration-free images, maximizing the quality of every shot.
• Back focus : The rear focal length is an industry-standard 55 mm, ensuring compatibility with a wide range of astrophotography accessories.
• Full-frame compatibility : Designed to work perfectly with full-frame sensors, eliminating vignetting and guaranteeing uniform image quality.

Dimensions and Technical Design

• Outside diameter : 84 mm, offering a stable, solid structure for use with large equipment.
• Total length : 76 mm, for compact mounting without cluttering the configuration.
• Front thread : M90*1 female, for secure connection to the FRA600 astrograph.
• Rear thread : M48*0.75, suitable for 2" filters for extended astrophotography possibilities and easy filter installation.

Benefits for users

This reducer is ideal for users looking to optimize their FRA600 astrograph for deep-sky astrophotography. Reduced exposure time and increased field of view enable faster, more effective capture of celestial objects. The integrated M48*0.75 thread facilitates the addition of 2" filters, making this reducer versatile for a variety of astronomical applications.