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Piggybacking an Ultrastar C

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#1 roberjam


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Posted 20 February 2019 - 04:10 PM

Hi Folks,


     I recently purchased a Starlight Xpress Ultrastar color camera.  I am relatively new to AP, and I wanted to try various types of methods.  The Ultrastar manual said the following about attaching the camera to a standard camera lens:


"A simple way of using the Ultrastar C is to attach a suitable camera lens and ‘piggyback’ it on a driven
telescope. You may find it difficult to buy a suitable ‘C’ mount lens, as the Ultrastar C chip is too large
to be fully illuminated by the cheaper versions that are widely available. You need a lens that is
specified for 2/3 inch sensors and these tend to be expensive ‘machine vision’ lenses. A relatively
cheap option is to use an SLR lens with a C to T or Pentax thread adaptor tube. The old Asahi 55 mm
F1.8 SLR lenses can be bought for as little as 20 pounds on Ebay and work very well with the Ultrastar
C. The correct focal distance for these lenses is about 45 mm, so you will need a C to lens thread
adaptor of about 32 mm overall length to achieve focus. A typical adaptor for a T2 lens is the Kipon
KP-LA-C-T2 and there are versions for EOS, OM lenses etc. In this mode, the field is fairly wide and
is good for comet and large nebula pictures. It also makes a very nice electronic finder.


After reading this, I purchased an adapter to mount the Ultrastar onto a lens, but then I got to thinking how would I piggyback this configuration on a telescope (C8 or C14 for now)?  If I used rings, I'd probably have to find a small ring for the Ultrastar and another larger ring for the camera lens.  Thus, I'd have to probably buy two sets of rings.  Even with a small ring, then I'd probably need overly long screws to hold the Ultrastar which has a diameter of only 3.34cm.  There must be a better way to accomplish this....  Any ideas would be appreciated.


Best Wishes,



#2 descott12


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Posted 20 February 2019 - 04:46 PM

I piggybacked my new Lunt Solar scope on my Evo 8 using a small wedge on the Lunt and a wedge clamp attached to the Evo where a finder scope would attach..  This weight of this setup is way more than what you are trying to do so I think it will work.


I think the wedge has a standard bolt hole that you could use to attach to either the camera or the lens.



Edited by descott12, 20 February 2019 - 04:50 PM.

#3 DuncanM



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Posted 20 February 2019 - 05:08 PM

Some lenses have a 1/4 x 20 tripod socket mount and you can purchase a tripod style camera mount for your OTA such as:



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