If you use a flatfield unit in front of your telescope instead of the RCU, that unit should not have a green-blue emission gap. Why? For calibration of the ThAr spectrum, the calibration script of MIDAS scans the flatfield spectrum to recognize as much spectral orders as possible. Order detection could fail with a non-uniform flatfield illumination. That depeds on your given unit.
Also important is the brightness of the flat unit in front of the telescope. It must be very bright to provide the same intensity level at the slit as the RCU which directly illuminates the slit of BACHES.
Also, please consider remote control of the calibration unit. This can only be accomplished by the RCU which contains a LAN female connector for connection to your local network. A fixed IP address can be assigned. You are able to control the RCU with any web browser, the web interface is implemented in the RCU. The standard calibration set with ThAr lamp only can not be controlled remotely!
We recommend the RCU to you, because we are sure that you will like the additional features as compared to the standard unit.
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|Usage||Professional use in astronomical / scientific research and university student education (astronomical internships). Suitable for advanced amateur astronomers, who already have experience in star spectroscopy|
|Spectral Resolution||average spectral resolution R = 18,000|
|Optimized Spectral range||392-800nm continuously (depending on sensor size)|
|Break-even value||10 mag. vis (50cm-telescope, S/N=20, 30min. exposure (see http://arxiv.org/abs/1406.2492)|
|Mechanical Design||Echelle-Spectrograph with high mechanical stability, FE designed, torsion deformation below 9μm at 180° rotation|
|Field size||optimized for sensor sizes ca. 15x10mm, 9μm Pixel (i.e. KAF-1603), usable with 7x4mm sensor sizes (i.e. ST-402) and DSLR‘s|
|Collimator aperture ratio||f/10|
|Optimized for focal ratio||optimized for 8" to 24" f/10 telescopes (full resolution from f/8 to f/12)|
|Adaptable to||CCD- and DSLR-cameras|
|Slit size||changeable 25 and 50μm slits. Slit length 125μm|
|Illumination||manual red LED for Slit-Focusing|
|Special Features||Including instruction for Spectra Callibration. solenoid switches between the light from the telescope and the ThAr calibrati on and fl atf ield lamp of the RCU|
|Guiding Port||with 1¼“-connection for eyepieces, video- or guiding cameras|
|Included Accessories||Standard: with ThAr lamp mounted on BACHES body (with separate power supply).
Professional with Remote Calibraion Unit (RCU) with built-in ThAr lamp and halogen fl atf ield lamp remotely controlled via web interface
|Optional Accessories||1.5x-barlow lense: to optimize ca. f/6.8-telescopes to f/10. Remote Calibration Unit (RCU) for professional callibration of Echelle Spectra|