Author Topic: acquired a celestron ci700 (losmandy g11)  (Read 202 times)

John Pierce

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acquired a celestron ci700 (losmandy g11)
« on: March 23, 2017, 02:04:02 PM »
so I just acquired a rather nice CI700 equatorial mount, this was a celestron branded 'cheapened' version of the Losmandy G11...   its a beast.  has alt and dec slo-mo motors but no goto.









I initially was thinking of using it for unguided piggyback as I don't really have a suitable scope for it, but now I'm wondering if I couldn't rebuild my Coulter 10" F/4.5 ... use one of Mark's Astrogoods alloy tubes, a better focuser than I now have, shorten up the tube enough that I can achieve focus with my DSLR (the secondary on the coulter is huge).  I have already replaced the coulter's primary mirror cell with one of Mark's creations, and the secondary spider with a curved vane spider from 1800destiny. 

http://www.astrogoods.com/atmparts.shtml

am I nuts for thinking this is a good idea?   the mount is rated for 60 lbs of instruments, 100 lbs total.   Celestron sold it with  C11 and C14 telescopes on it :-O


John Pierce

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Re: acquired a celestron ci700 (losmandy g11)
« Reply #1 on: March 23, 2017, 04:55:39 PM »
hmmm, said coulter has a 65mm (minor axis) secondary, so rough calculations suggest that with a 12" OD tube, plus focuser minimum height plus the 44mm flange distance of a EOS DSLR, I'd only get a 16mm diameter image circle before the image starts to darken significantly.    not good enough for an APS-C DSLR!! (which has a 28mm or so image circle)