DeltaOptical 0.5x 2″ Focal Reducer
This focal reducer has a 0.5x reduction ratio. It halves the effective focal length of your telescope and doubles the field of view at the same time. For astrophotographers using small sensors, this means better use of the chip and shorter exposure times. A focal reducer for astrophotography of this type is a proven solution when you want to capture large objects without having to stitch multiple images together.
Metal barrel with M48x0.75 threads
The metal barrel carries M48x0.75 threads on both ends. It fits neatly into standard filter and adapter systems. The 2″ barrel diameter ensures compatibility with common focusers and telescope draw-tubes. 2″ fitting with M48x0.75 threads keeps your optical train simple - no extra adapters needed.
Key specifications
| Parameter |
Value |
| Reduction ratio |
0.5x |
| Barrel diameter |
2″ |
| Thread (both ends) |
M48x0.75 |
| Body material |
Metal |
Who is this focal reducer for?
- Astrophotographers who want a wider field of view without changing their telescope
- Anyone shooting with a small camera sensor and wanting to use the full chip area
- Observers who want to capture large deep-sky objects in a single frame
- Users with a 2″ focuser looking for a straightforward optical train
Why use a focal reducer?
A focal reducer shortens the effective focal length of your telescope. This gives you a wider field of view and a faster focal ratio. A faster focal ratio means shorter exposure times, which is important when photographing faint deep-sky objects. You can image large targets such as the Andromeda Galaxy or the Pleiades in a single shot, without the need for complex mosaics.
Compatibility
The 2″ barrel fits most standard telescope focusers. The M48x0.75 threads on both ends make it easy to attach filters or additional adapters directly - no step rings required in most setups.
