Starfield Optics 2.5" Adjustable 0.8x Reducer.

  Optimize Your Astrophotography with Starfield Optics 2.5" Adjustable 0.8x Reducer Effortless Back Focus Adjustment: Designed for easy setting of back focus to 55mm, with an adjustment scale of 14.87mm for precision. Adapter-Free Solution: Eliminates the need for multiple adapters, even when using additional accessories like filter wheels and rotators. Fine Tuning Made Simple: Allows for minor adjustments to achieve perfect focus and image quality. Universal Compatibility: Direct attachment to telescope focusers, with potential use on various telescope models (larger than 102mm) with the appropriate adapter. Comprehensive Focuser Calculations: Provides specific back focus requirements for different telescope models (e.g., 102mm/f/7 - 69.87mm, 155mm/f/8 - 62.57mm). Ease of Installation: Includes a 1.5mm Allen key for loosening and attaching the reducer to the focuser. Internal Filter Integration: Designed to accommodate filters within the reducer, enhancing astrophotography capabilities. Specifications Design: Corrector and reducer tailored for refractor telescopes. Telescope Connection: Features an M63x1 external thread for telescope attachment. Camera Connection: Equipped with an M48x0.75 external thread for camera compatibility. Reduction Factor: Offers a 0.8x reduction capability. Lens Composition: Includes 3 lenses, one of which is an ED (Extra-low Dispersion) element. Coating: Benefits from multi-layer coating and internal blackening for improved image quality. Working Distance: Provides a variable and adjustable working distance. Adjustment Range: Features a 0-17 mm stepless adjustment range for precise positioning. Suitability: Compatible with refractor telescopes ranging from 102 mm to 155 mm in aperture and equipped with 2.5" focusers.