The Baader Triband Solar SCT's are available in apertures of 8", 9¼" and 11".
The telescope features a Celestron Schmidt Cassegrain optical tube assembly (C9.25) with Triband ERF (energy rejection filter) coated Schmidt corrector plate and includes rear ventilated heat shields (with Neodymium-magnetic holders) to keep the tube and secondary mirror cool.
The transmission windows of the ERF are designed for Calcium-K, Continuum (incl H-beta and O III), H-alpha and S II. This Triband-coated Schmidt corrector plate reflects more than 90 percent of the incoming light, so no additional ERF is required. The large aperture of the Triband SCT range offers high resolution for solar observing or imaging.
The Triband SCT on its own is not a complete Solar telescope. To permit this the following additional components are required (for H-Alpha use);
H-alpha Filter: For optimum performance we recommend use with a Solar Spectrum H-alpha filter. These are available in a range of bandpass and etalon sizes. For purely imaging applications we advise the Solar Observer 1 as this has an etalon suitable for use with typical high frame rate cameras. For visual use a filter with a larger etalon should be selected. Please call us for details.
Telecentric: A rear mounted H-Alpha filter should operate at F30. The Baader TZ-3 telecentric system provides an optimum match for this telescope, maximising contrast.
Optionally you can also add
Telecompressor / Reducer: To match the Baader range of Telecentrics and fit directly into the Solar Spectrum filter, we offer 0.4x and 0.7x Telecompressors (Reducers). These have a corrected filed and are primarily design for imaging. They can be used visually but you will see a vignetted area within the field of view of the eyepiece.
Telecompressors are useful for either increasing the available field of view or for improving image quality during poor seeing.
The 0.4x Telecompressor may also be used as a 0.3x by adjusting its back focus distance to the sensor. By using both the 0.4x and 0.7x Telescompressors with this telescope, the following focal lengths can be achieved;
| 9.25" Triband with TZ-3 |
7050mm |
| TZ-3 plus 0.7x Telecompressor |
4935mm |
| TZ-3 plus 0.4x Telecompressor |
2820mm |
| TZ-3 plus 0.4x with back focus for 0.3x |
2115mm |
The Triband SCT also has windows in its ERF at the continuum band (480 - 515 nm) and the CaK band (380 - 400 nm). For use at these wavelengths the following additional items are required;
Continuum: Any 2" Herschel Wedge can be used. We recommend either the Baader 2" Cool Ceramic Safety Wedge or the 2" APM Herschel Wedge. For optimum results the Wedge should be used with a Continuum Filter. The Wedge is used without the TZ-3 in place.
Calcium-K: For simple K Line images a Herschel Wedge can be used together with the Baader K Line filter in place of the Continuum. This will provide images of the different nature of the Chromosphere at this wavelength. Note that this filter is 1.25" only and is therefore mounted on the nose of the camera. For maximum detail and also for capturing prominences in Calcium K, a Solar Spectrum CaK-filter is recommended. These are built to order, price on application. Use with the Solar Spectrum filter requires the TZ-3 which is designed to work with CaK in addition to H-Alpha.
Getting the best from a High Resolution Solar Telescope
A High Resolution Solar Telescope can provide outstanding images of our nearest star. However its additional aperture can highlight poor seeing. To ensure you get the most from your Triband SCT we recommend its use with the Airylab Solar Scintillation Monitor (SSM). This is a device that monitors seeing quality, and if used together with Airylabs Genika Software (supplied free with all Mono Point Grey (now FLIR) cameras), it will trigger capture of images at the optimum seeing level. This saves a lot of time and can almost gaurantee the quality of the images you will capture.
Other uses
Thanks to its Triband filter, the Triband SCT can be used for conventional Deep Sky Imaging and planetary imaging including the Baader U filter for imaging of Venus. All our standard correctors offered for the Celestron C Models (not Edge) are compatible with the Triband SCT.
Specification
OPTICAL DESIGN : Schmidt Cassegrain
APERTURE : 234.95 mm (9.25 in)
FOCAL LENGTH : 2350 mm (93 in)
FOCAL RATIO : 10
OPTICAL TUBE : Aluminum
OPTICAL COATINGS : StarBright XLT
SECONDARY MIRROR OBSTRUCTION : 3.35 in (85mm)
SECONDARY MIRROR OBSTRUCTION BY AREA : 13 %
SECONDARY MIRROR OBSTRUCTION BY DIAMETER : 36 %
OTA Length 22 in (559mm)
OTA Weight 20 lb (9.07 kg)
