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DayStar Quark GEMINI two-in-one combo for SCT and Mak - Chromosphere and Prominence

CHF 2'380

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DayStar Combo Gemini H-Alpha - For SCT, Mak and F/15-F/30 refractors

The Gemini Combo combines H-alpha filters Prominence and Chromosphere for instant switching via a side-mounted slider. Enjoy the best of both bandwidth options in a single tool, without hardware swapping or refocusing.

Presentation

The Gemini Combo allows :

Easily switch between Prominence (wide bandwidth) and Chromosphere (high contrast narrow bandwidth) like an optometric test.
Instant observation without filter exchange or refocusing.
Compatible with SCT, Maksutov and refractors via optional telecentric barlows (2.8x or 4.3x).
Lightweight, compact all-in-one device, eliminating the need for additional adapters.
Internal baffles for enhanced contrast and optimized 656 nm AR coatings.

Important: for SCT and Maksutov, a front-mount energy rejection filter (ERF) is mandatory to protect the optical tube and obtain optimum performance.

Technical specifications

Type	Gemini H-alpha Combo filter (Prominence + Chromosphere)
Compatibility	SCT, Maksutov, F/15-F/30 refractors
Eyepiece outlet	1.25″ standard, 1.25″ snout included + 2° off-axis adapter for ERF
Barlow / Optics	No integrated Barlow - 0 power, filter only. Optional telecentric barrows available.
Blocking filter	Integrated, 25 mm
Clear aperture	21 mm
Power supply	USB 5 V 1.5 A, incl. 90-240 V mains adapter
Tuning	Wheels for wing shift ±0.5 Å with notches every 0.1 Å; LED status: power, warming, ready, fault
Warranty	5 years
Supplied box	Hard case for protection and transport
Observation	Full disk up to ~1800 mm focal length; no aperture limitation, use with SCT and Maks off-axis ERF
Optional accessories	8h battery pack

Prominence versus Chromosphere

Criteria	Prominence	Chromosphere
Bandwidth FWHM	Wider (>0.6 Å) - brighter	Narrower (<0.5 Å) - better surface contrast
Filaments	Difficult to observe	Visible and detailed
Protuberances	Very shiny blade	Visible but less brilliant
Contrast	Less contrast, brightness priority	High contrast, ideal for chromospheric detail
Recommended use	Quick visual observation	Detailed observation and astrophotography

Important instructions for SCT / Maksutov

SCT: use an off-axis front-mount ERF with aperture reduction to protect the secondary mirror.
Maksutov: ERF front-mount mandatory to avoid overheating the optical tube.
Refractors F/15-F/30: insert the Combo Gemini directly into the bend, no additional adjustment required.