Dark Clear Skies · SVBONY
SVBONY SV193 0.8× Reducer / Field Flattener for SV503 80ED
The SVBONY SV193 W9152B is the 0.8× reducer and field flattener matched to the SV503 80ED f/7. It reduces the image scale and corrects field curvature, helping you frame wider deep-sky targets with a compatible camera.
What changes in your images
At the nominal reduction factor, the telescope’s 560mm focal length becomes approximately 448mm and f/7 becomes f/5.6. These are calculated values. The same camera covers a wider field, while each target occupies fewer pixels than it does at the native focal length.
The matched flattener addresses the telescope’s curved focal surface. Accurate spacing and alignment still matter, particularly when assessing stars near the corners. Exposure time also depends on sky brightness, camera settings, filters and the target.
Choose the exact telescope version
Select this W9152B version for the SV503 80ED. Other SV193 reducers and flatteners are designed for different telescopes; the model family name or a matching thread alone does not establish optical compatibility.
Build the 55mm camera spacing
Measure the specified 55mm from the reducer’s camera-side reference shoulder to the sensor plane. Add the camera’s sensor recess and every adapter, drawer, filter wheel or guider behind the reducer. A camera-specific bayonet adapter may be needed for a DSLR or mirrorless body.
Assemble the imaging train securely, focus on a star field and inspect both the centre and corners. Filter glass and the rest of the optical train can affect the optimum spacing; follow the corrector guidance and make small, controlled adjustments where needed.
Optics and mechanical setup
Fully multi-coated optical surfaces help control reflections, while the metal housing supports a rigid imaging connection. Support heavier camera trains and check that no threaded component bottoms out before its shoulder seats correctly. Take appropriate flat frames for the completed setup.
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Technical specifications
| Specification | Details |
|---|---|
| Model / SKU | SV193 / W9152B |
| Matched telescope | SV503 80ED f/7 |
| Optical factor | 0.8× |
| Calculated focal length | 448mm from 560mm at nominal 0.8× |
| Calculated focal ratio | f/5.6 from f/7 |
| Nominal camera back focus | 55mm |
| Connection | 2-inch barrel; M48 × 0.75 camera thread |
| Lens coatings | Fully multi-coated |
| Optical construction | Three elements in two groups |
| Lens edges | Blackened |
| Manufacturer-listed net weight | 164g |
What's included
One SV193 W9152B reducer / field flattener. Telescope, camera, camera-specific adapter, filter holder and application-specific spacers are separate items.