Observe two different views of the Sun with your compatible telescope: the Quark Gemini switches between the chromosphere and the prominences without changing filters. Built-in 4.2× telecentric eyepiece; F/4 to F/8 refractors are recommended; protective filters must be adapted to the instrument.
CHF 2'380.00incl. Swiss VAT
Will be ordered for you
Timeframe: 10 days to 3 weeks
Estimated shipping: Between November 21 and 26, 2026
Turn your refractor into a safe, portable solar telescope. The QUARK Gemini is a true "two-in-one". It simultaneously contains Prominence and Chromosphere with an instant switchover from one to the other, without changing eyepieces or refocusing.
Amateur astronomers and teachers can demonstrate the differences between the surface and prominences one after another, while astrophotographers can quickly capture comparative images.
The QUARK Gemini is an all-in-one H-alpha eyepiece for refractors (ideally F/4 to F/8), combining a 4.2× telecentric Barlow lens optimized for 656 nm and two switchable Fabry-Pérot filters for the prominence and chromosphere. Includes 1.25″ and 2″ slip-on adapters, USB power supply, tuning control, and built-in protection.
An achromatic, ED, apochromatic, or Petzval-compatible eyepiece can serve as the foundation of your solar setup. The Gemini, with its built-in telecentric lens, is primarily designed for F/4 to F/8 refractors. Switching between its two filters allows you to compare details of the chromosphere and prominences using the same instrument.
Mechanical compatibility alone is not enough: the diameter, focal ratio, and energy rejection must be verified with the DayStar Official Compatibility Checker. For an SCT or a Maksutov, see the entry for the Gemini Combo and its installation requirements. Each configuration must comply with the DayStar instructions.
Visit DayStar Solar Accessories allow you to adapt the connection to the eyepiece or camera: 1.25-inch or 2-inch connectors, T- or C-mounts, and adapters, depending on the model. Thread compatibility, focus extension, and focus must be checked for each combination. Accessories are sold separately.
In astrophotography, a DayStar tilt adapter can help reduce Newton's rings. The results depend on the camera and the settings; see the Manufacturer's installation instructions to choose the right adapter.
DayStar has been developing solar equipment for over 50 years. Whether for an introductory course, an educational activity, or an imaging program, Contact Deep Space Astronomy Please provide the model of your instrument, your camera (if applicable), and your lenses: we'll help you choose a suitable setup and provide a quote.
| Type | Eyepiece H-alpha Gemini - switchable double standard |
|---|---|
| Models | Prominence & Chromosphere integrated, slide-action |
| Integrated Barlow | 4.2× telecentric, optimized for 656 nm |
| Clear aperture | 22 mm |
| Blocking filter | 12 mm integrated |
| Eyepiece outlet | Standard 1.25″; 1.25″ and 2″ snouts included |
| Power supply | USB 5 V 2 A. 90-240 VAC mains adapter included |
| Control | Two tuning knobs with a resolution of +/-0.5 Å and graduations every 0.1 Å, status LED |
| Warranty | 5 years |
| Optimum use | Refractors f/4–f/8; full disk up to ~450 mm focal length |
| Consumption | Low - compatible with optional 8h battery pack |
| Criteria | Prominence | Chromosphere |
|---|---|---|
| Bandwidth FWHM | Wider → brighter | Narrower → better surface contrast |
| Filaments (on disc) | Difficult to see | Visible and detailed |
| Protuberances | Very bright, with a limb | Visible, but less brilliant |
| Detail contrast | Less contrast, brightness priority | High - ideal for chromospheric detail |
| Recommended use | Rapid visual observation of protuberances | Astrophotography and detailed surface observation |
With Gemini, you can instantly switch between them as needed without changing equipment.
Yes—just slide the side arm to switch between them instantly.
Yes, but only with a complete and validated solar power setup that includes the power output required for your instrument, and in accordance with the manufacturer's instructions.
