Baader Triband-SCT - multi-purpose telescope based on SC, for sun + deep sky 11 inch SCT

Triband SCT - Versatile telescopes for professional applications
Based on the proven Schmidt-Cassegrain (SC) telescopes, the Triband SCs with Triband ERF-coated Schmidt plate were developed. They are the ideal basis both for detailed H-alpha solar observation with large aperture and for narrow-band deep-sky photography.

With large aperture on the sun
The triband coating is an energy protection filter for solar observation that does not impair deep-sky suitability. Heat shields prevent the tube from heating up.
The triband coating is an energy protection filter for solar observation that does not impair deep-sky suitability. Heat shields prevent the tube from heating up.
It is a widespread myth that small telescopes are sufficient for observing the sun because high magnifications are not possible during the day.

The now widely used, nice little H-alpha and CaK telescopes are good for a quick look at the sun and to see it completely; but to resolve fine details, you need aperture and focal length for those moments when the seeing conditions are perfect.

The Baader Triband SCT's have the energy protection filter necessary for the CaK and H-alpha filters of SolarSpectrum already integrated into the Schmidt plate. The costs for an energy protection filter, which would be truly "astronomical" for apertures between 8 and 11 inches, are eliminated. Thanks to the triband coating, the telescope remains fully usable for narrow-band photography despite being designed for solar observation!

The special triband ERF Schmidt plate of the Triband-SCT has the following transmission ranges: 380 to 400 nm, 480 to 515 nm and 630 to 680 nm.
In addition, it is blocked in the UV range (below 380 nm) and in the IR range (above 680 nm) to prevent both short-wave radiation and heat generation.

The triband Schmidt plate is blocked in particular in the IR range up to 1450 nm and thus prevents the tube from heating up. An additional large and precisely polished energy protection filter is therefore not required, and the optical precision of the Schmidt plate is fully maintained.

Additional, rear-ventilated heat shields at the front of the tube and in front of the secondary mirror effectively reduce the absorption of radiant heat by the tube. This allows you to use the full resolution that is possible at your observation site. With videography, extremely high-resolution detailed images of the sun are possible. But in three passbands - not just in H-alpha. You can observe the sun in H-alpha or CaK light with a SolarSpectrum filter as well as in the continuum with a Herschel wedge or an ASTF filter.

The new system is also visually impressive - in moments of good seeing, you will see the sun more breathtakingly than ever before.

TriBand pre-filter for narrow-band observations
A triband SCT consists of a Schmidt-Cassegrain optic with tube and triband ERF-coated Schmidt plate as well as ventilated heat shields for the tube edge and secondary mirror (with neodymium magnet mounts). The transmission windows are designed for calcium K, continuum (incl. H-beta and O III), H-alpha, S II, i.e. similar to a UHC filter, and allow the use of additional narrowband filters.

Depending on the application, you may need additional accessories:
H-alpha:
Solar Spectrum H-alpha filter, TZ-3 telecentric and TK0.4 or TK0.7 telecompressor. A D-ERF filter is not additionally required.

CaK:
Solar Spectrum CaK filter, K-Line filter plus pre-filter for solar observation in calcium light

Continuum:
Safety Cool-Ceramic Herschel wedge and suitable narrow band filters if necessary.

Deep-Sky (not for solar observation!):
Deep-sky filters depending on the type of application (RGB / H-beta / O-III / H-alpha / S-II)

Solar observation in H-alpha light
SolarSpectrum filters for H-alpha or CaK can be connected directly
The Triband-SC were developed for the SolarSpectrum H-alpha filters. The energy protection filter integrated in the Schmidt plate eliminates the need for an additional D-ERF. The SolarSpectrum filters require the 2" Research Grade TZ-3 Telecentric System (3x focal length) (#2459257 , € 445,-) to perform best at f/30; with the Research Grade H-alpha 0.4x Telecompressor 2" for Solar Spectrum (#2459260 , € 366,-) with 16mm corrected field of view you can almost reach the original focal length of the telescope again and can work with lower magnifications both visually and photographically.

Solar observation in calcium light
In addition to the transmission window between 630 and 680 nm for H-alpha observation, the energy protection filter has a second window between 380 and 400 nm, in dark blue/UV. It allows the use of SolarSpectrum CaK filters without an additional energy protection filter.

In addition, the Baader Calcium GEN-II 1¼" (#2961590 , € 285,-) can be used, but only in conjunction with another pre-filter such as a Baader Cool-Ceramic Safety Herschel Prism 2" Mark II Photo (#2956510P , € 645,-) or AstroSolar Photo Film ND 3.8 (also available as ready-mounted BDSF: OD 3.8 Baader Digital Solar Filter 200mm (#2459376 , € 157.91)).

Solar observation in continuum (white light)
With a Herschel wedge or an ASTF front filter, white light observation with large aperture and resolution is possible
With a Herschel wedge or an ASTF front filter, white light observation with large aperture and resolution is possible
Solar observation in white light is possible with a Baader Cool-Ceramic Safety Herschel Prism 2" Mark II Photo (#2956510P , € 645,-) or a temperature-compensating ASTF front filter made of Astrosolar foil. The sun appears slightly light green. For increased contrast we recommend a red filter such as H-alpha 2" bandpass filter (20nm) (#2961853 , € 165,-) to reduce the influence of seeing, alternatively the narrower band O-III 2" Super-G filter (9nm) - CMOS optimized (#2961551 , € 165,-) .

Note on observing the sun
Please note that a device in the performance class of a triband SCT is not a grab-and-go telescope: Smaller telescopes with less magnification show nice images even in poor seeing conditions, but a high-end telescope that pushes the limits of what is technically possible also requires a suitable observation site. Make sure that the surroundings do not cause any air turbulence - only then can you exploit the telescope's full potential!

Deep-sky narrow-band observation + narrow-band photography
The popular Celestron Schmidt-Cassegrains, a system that has been tried and tested in the night sky for decades, form the basis. Therefore, they are also compatible with all accessories for Schmidt-Cassegrains - from filter drawers such as the UFC to focusers such as the Baader Diamond SteelTrack with optional motorized focuser or the Celestron focusing motor #821160 to reducers.

In contrast to pure H-alpha telescopes, the Triband-SCT can also be used at night: the filter coating allows CaK, H-Beta, O-III, H-alpha and S-II to pass through, so that the telescope can also be fully used for narrowband or Ultra UHC photography - whether originally with f/10, with a reducer or even with the HyperStar system at f/2. In addition, UV filters ( U-Venus filter 2" (350nm) (#2458291 , € 334,-) ) and IR pass filters ( IR pass filter 2" (685nm) (#2458386 , € 143,-) ) can be used with highly surprising image contrast. The SC optical system proves to be corrected over a much wider spectral range than the best apochromat.