Description
Starfield Adjustable 1.0x Field Flattener — 80–155mm Refractors
The Starfield 1.0x Adjustable Flattener is built for refractor astrophotography when you want sharper stars toward the edges without changing the telescope’s focal length. The adjustable design makes it easier to achieve the correct back spacing—even when your imaging train includes accessories such as filter wheels and rotators.
Why adjustable matters: Set the adjustment for your telescope, lock it in, and if fine-tuning is needed, it’s done with a small twist—rather than rebuilding your imaging train with spacer rings.
Manual (Recommended)
For the complete step-by-step setup and spacing workflow, use the official PDF manual: Starfield Reducer & Flattener Manual (PDF) .
Compatibility & Target Settings (As Listed)
This flattener is designed for refractor telescopes ranging from 80mm to 155mm. Use the table below to find your telescope class and the corresponding target setting.
| Telescope | Target setting (mm) |
|---|---|
| 80mm / f/6 | 81.2 |
| 90mm / f/6 | 82.5 |
| 102mm / f/7 | 75.3 |
| 115mm / f/7 | 73.0 |
| 130mm / f/7 | 69.7 |
| 140mm / f/6.5 | 68.0 |
| 155mm / f/8 | 57.0 |
Tip: If your imaging train changes (new camera, added rotator, filter wheel, etc.), re-check spacing using the manual.
Installation Summary (Quick)
The flattener attaches directly to Starfield telescope focusers using the locking ring system described on the product page.
- Using a 1.5mm Allen key, loosen the three screws about a half turn.
- Unscrew and remove the lock (locking ring).
- Thread the flattener onto the focuser.
- Set spacing using the official manual: Open the manual (PDF) .
Key Product Notes
- 1.0x correction: improves field flatness without reducing focal length.
- Adjustment-based spacing: set the required adjustment for your telescope; fine-tune with a small twist if needed.
- Accessory-friendly: intended to help you reach required spacing even with filter wheels and rotators.
- Filter note (as listed): filters can be added inside the unit.
FAQ
What does a field flattener do?
A flattener corrects field curvature so stars remain sharper toward the edges of your image—especially noticeable with larger sensors.
Does this change my focal length?
No—this is a 1.0x flattener, so it is intended to keep your telescope’s focal length while improving edge performance.
How do I set the spacing?
Use the official manual for the full spacing workflow: Starfield Reducer & Flattener Manual (PDF) .
Can I use it with a filter wheel and rotator?
Yes—the product description specifically calls out accessories such as filter wheels and rotators as part of the intended use.
What telescope sizes is it designed for?
The product is designed for refractor telescopes from 80mm to 155mm (see the target settings table above).