Product Overview The Askar 65PHQ 0.75x Full Frame Reducer is a dedicated reducer designed for the Askar 65PHQ astrograph. Its quadruplet optical design reduces the native 65PHQ optical system by 0.75x, changing the telescope to approximately f/4.8 with a reduced focal length of 312mm. This accessory is intended for deep-sky astrophotographers who want a wider field of view, faster imaging speed, and full-frame camera support while continuing to use the 65PHQ as the main telescope. Who Is This Product Best For? This reducer is best for Askar 65PHQ owners who want to make their imaging setup faster and wider. It is suitable for beginner, intermediate, and advanced astrophotographers using the 65PHQ for wide-field nebulae, Milky Way regions, large star fields, and portable deep-sky imaging rigs. Why Choose This Product? Dedicated reducer for the Askar 65PHQ astrograph. 0.75x reduction changes the 65PHQ from f/6.4 to approximately f/4.8. Reduces focal length to approximately 312mm for a wider field of view. Quadruplet reducer design supports full-frame astrophotography. Standard 55mm back focus works with many common astronomy camera setups. Built-in M48x0.75 2-inch filter thread supports convenient filter installation. Excellent option for faster imaging of large deep-sky objects. Recommended Uses Wide-field deep-sky imaging with the Askar 65PHQ Large nebula and star-field astrophotography Full-frame camera imaging with the 65PHQ Portable travel imaging rigs Shorter exposure imaging compared with the native f/6.4 65PHQ configuration Compatibility and Accessory Notes This reducer is designed specifically for the Askar 65PHQ. When installed on the 65PHQ, it provides a reduced focal ratio of approximately f/4.8 and a reduced focal length of approximately 312mm. The vendor specifies a 55mm back focus and includes a built-in M48x0.75 2-inch filter thread. Use appropriate camera adapters, spacers, filter drawers, and filters to maintain the required back focus. Cameras, filters, spacers, and the telescope OTA are sold separately unless explicitly included in a bundle. Important Limitations This is not a standalone telescope or imaging lens. It is specifically intended for the Askar 65PHQ and should not be assumed compatible with other telescopes. It is an astrophotography accessory, not a visual observing accessory. Correct 55mm back focus is required for best edge performance. It widens the field and reduces focal length, so it is not the right choice when more magnification or smaller-target image scale is needed. Frequently Asked Questions Is this reducer good for beginners? Yes, if the user already owns an Askar 65PHQ and is comfortable setting camera spacing. The 55mm back focus is common, but it still needs to be set accurately. What is it best used for? It is best used for wide-field deep-sky astrophotography with the Askar 65PHQ, especially large nebulae, star fields, and travel imaging setups. Is it for visual observing or astrophotography? This is an astrophotography accessory. It is not recommended for visual observing. What telescope is it compatible with? It is designed for the Askar 65PHQ astrograph. What camera spacing does it require? The required back focus is 55mm. Does it support full-frame cameras? Yes. The vendor identifies it as a full-frame reducer for the 65PHQ. Does it accept filters? Yes. It includes a built-in M48x0.75 2-inch filter thread. When should it not be recommended? Do not recommend it to users who do not own a 65PHQ, need a visual accessory, or want to keep the longest possible focal length for smaller objects. Our Recommendation Ontario Telescope recommends the Askar 65PHQ 0.75x Full Frame Reducer for 65PHQ owners who want a faster, wider imaging system for large deep-sky targets. It solves the problem of making the 65PHQ more efficient for wide-field imaging while maintaining a dedicated optical match. Use the native 65PHQ configuration instead when maximum focal length is preferred. Optical Diagram Reports The following vendor-supplied graphics provide reducer specifications and optical information for the Askar 65PHQ imaging setup.
