Askar F3.9 Full Frame Reducer for FRA600

Product Overview

The Askar F3.9 Full Frame Reducer for FRA600 is the dedicated focal reducer for the Askar FRA600 astrograph. It reduces the native 600mm f/5.6 system to a faster 420mm f/3.9 imaging configuration, making the FRA600 better suited to wide-field deep-sky imaging and shorter exposure times.

Who Is This Product Best For?

This reducer is best for FRA600 owners who want a faster optical system, a wider field of view, and full-frame imaging support for large nebulae, star fields, and extended deep-sky targets.

Why Choose This Product?

• Dedicated reducer for the Askar FRA600.
• 0.7x reduction changes the FRA600 to 420mm at f/3.9.
• Designed for full-frame imaging with the FRA600.
• Standard 55mm back focus for common astronomy camera setups.
• M48 connection with internal 2-inch filter thread support.

Recommended Uses

• Faster wide-field deep-sky imaging with the FRA600.
• Large nebulae, star fields, and extended objects.
• Full-frame camera setups when correctly spaced.
• Imaging configurations where shorter exposure times are desired.

Compatibility and Accessory Notes

This reducer is designed for the Askar FRA600. It provides a 0.7x reduction factor and should be spaced to the specified 55mm back focus from the camera side. It includes an internal M48x0.75 thread for standard 2-inch mounted filters.

Important Limitations

• Designed for the FRA600; do not assume compatibility with other telescopes.
• Requires correct 55mm camera spacing for best optical performance.
• Primarily an astrophotography accessory and not recommended for visual observing.
• The FRA600 telescope, camera, adapters, and filters are not included.

Frequently Asked Questions

Is this good for beginners?

It is straightforward for FRA600 owners who understand camera spacing, but a beginner should confirm their adapter stack reaches the required 55mm back focus.

What is it best used for?

It is best used for wide-field deep-sky imaging with the FRA600 at a faster f/3.9 focal ratio.

Does it work with full-frame cameras?

Yes, it is intended as a full-frame reducer for the FRA600 when the imaging train is configured correctly.

Does it require additional accessories?

Most setups will need the correct camera adapter or spacer combination to achieve 55mm back focus.

Our Recommendation

Ontario Telescope recommends this reducer for FRA600 imagers who want a faster, wider-field configuration. Choose it for nebulae and large deep-sky objects; stay native at 600mm when you want a narrower field or more image scale.