Askar 0.75x Reducer for 91F
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Vai al moduloAskar 0.75x Reducer for 91F – Imaging Optimization and Field Correction
The Askar 0.75x Reducer for the 91F telescope is designed to significantly enhance astrophotography performance. It reduces the focal ratio from f/6.7 to f/5, bringing the focal length down to 455 mm. This results in a wider field of view and faster exposure times, ideal for capturing faint deep-sky objects such as nebulae, star clusters and fast-moving targets.
Triplet Optical Design with Integrated Field Correction
The triplet optical system provides effective field curvature correction, ensuring sharp stars across the frame. Supporting a 44 mm image circle, the reducer is fully compatible with full-frame sensors. Its CNC-machined aluminium body ensures mechanical precision and durability.
Compatibility and Thread Interfaces
The reducer offers a backfocus distance of 55 mm from the M48 thread. It includes a rear M59x1 thread and supports 2" filters. With the supplied adapters, it integrates easily into a variety of imaging setups.
Technical Specifications
| Specification | Value |
|---|---|
| Compatibility | Askar 91F |
| Resulting Focal Ratio | f/5 |
| Resulting Focal Length | 455 mm |
| Optical Design | Triplet |
| Backfocus | 55 mm (from M48 thread) |
| Rear Thread | M59x1 |
| Filter Compatibility | M48x0.75 (2" filters) |
| Included Adapters | M54x0.75, M48x0.75 |
| Supported Image Circle | 44 mm (full-frame) |
| Weight | 0.3 kg |
| Construction | CNC-machined aluminium with threaded caps |
Ideal for Wide-Field Astrophotography
The Askar 0.75x Reducer transforms the 91F into a high-performance wide-field imaging instrument, increasing speed and enhancing the ability to capture extended deep-sky structures with clarity.