DCS 40ED Guidescope — Compact ED Optics for Autoguiding
The Dark Clear Skies 40ED is a compact 40 mm guidescope for use with a separate astronomy guide camera. Its three-element ED optical design, carbon-fibre tube and helical focusing system provide a compact guiding assembly for an astrophotography rig.
Built around the guide camera
A guidescope lets a guide camera monitor stars while your guiding software sends tracking corrections to a compatible mount. The 40ED provides the optics and mounting interface; a guide camera and guiding control system are required separately.
The three-element (2+1) ED objective is designed to control colour aberration. A helical focuser allows fine focus adjustment, and the locking ring helps retain the selected position once stars are focused.
Camera connections and mounting
- T2 connection: M42 × 0.75 thread for a matching threaded camera connection or suitable adapter.
- 1.25-inch connection: supplied adapter for a compatible guide-camera nosepiece.
- Mounting: bracket and dovetail foot for a compatible finder shoe.
- Focus spacing: the supplied 10 mm T2 extension provides another spacing option; the correct arrangement depends on your camera’s sensor position.
Check the camera thread or nosepiece, available focus travel and finder-shoe fit before ordering. T2 is M42 × 0.75; it is not interchangeable with M42 × 1 photographic lens threads. A matching thread alone does not guarantee that every camera will reach focus.
Specifications
| Objective aperture | 40 mm |
|---|---|
| Optical design | Three-element ED, 2+1 arrangement |
| Tube | Carbon fibre |
| Focusing | Helical adjustment with locking ring |
| Camera interfaces | T2 (M42 × 0.75) and 1.25-inch adapter |
| Primary application | Autoguiding with a separate guide camera |
Getting the best from your setup
Mount the guidescope firmly, secure the camera and support its cables. Movement between the guidescope and main telescope can affect the final image even when the guiding graph looks good. Focus on stars, lock the adjustment gently and recheck focus before a session.
Suitability depends on your imaging focal length, guide-camera pixel size and the rigidity of the complete setup. Telescope aperture alone is not a reliable way to choose a guiding system. For setup and troubleshooting, see the PHD2 guiding manual.
What is included?
- DCS 40ED mini guidescope
- Mounting bracket and dovetail foot
- T2-to-1.25-inch adapter
- 10 mm T2 extension
- Dust caps
- Plastic storage case
Guide camera, mount and main telescope are sold separately.
Need help matching a camera?
Tell us your guide-camera model, main telescope and mounting arrangement so we can help check the connections and focus-spacing requirements.
