Guest
In this video I show the build process of my Celestron Triple RASA11 Astrograph. This 350kg telescope consists of three Celestron RASA11 v1 Telescopes, each with 620mm focal length and fast f2.2 on an Italian 10micron GM3000HPS Observatory grade mount, permanently installed in my backyard Observatory. I show the different stages of this setup, starting with the installation of the huge 10micron mount and the 120kg octagonal steel pier, through the different telescope installations to the final stage with three RASA11 Astrographs. My garden observatory here in the Ruhr area in Germany is in a light-polluted Bortle 7 zone where you can only see the brightest stars in the sky. In order to do astrophotography there and to be able to take pictures of fainter objects, you need fast optics and very long exposure times to be able to suppress the background noise of the sky background as effectively as possible. The fast RASA optics help with this. In addition, my goal was to have to change filters as rarely as possible. Due to the construction of the RASA Astrographs, you cannot use an electronic filter wheel, but have to change the filters manually. This is very time-consuming with R,G,B, Ha, OII, SII and Clear filters. With three RASAs, the effort is much less, especially since one of the RASAs is equipped with a ZWO ASI2600MC on-shot colour camera. Thus, per 8h night, I can collect a total of 8h colour data and 2x8h monochrome data, i.e. 24h total exposure time. With this set-up I can take the Bortle 7 challenge! For more info and astro images please visit my website: More astro videos can be found on my Youtube channel Music by State Azure, Greg Foat and Rodney Holmes
