Orion 10" Newtonian

Orion 10" Newtonian on CGE mount is my strictly imaging setup. I have been inspired by outstanding images of Hap Griffin while searching for my secondary OTA for deep sky imaging. The initial setup included:

  • Orion 10" Newtonian OTACelestron CGE mount - sitting on Omega-2 pier

  • Celestron C80ED guiding scope

  • Parallax 12" OTA rings for mounting the Newtonian

  • Two Losmandy  14" dovetails (one for 10" OTA and the other for C80ED),

  • Losmandy 108mm finder rings for mounting C80ED

  • Orion AccuFocus for Newtonian

  • Orion AccuFocus for C80ED

  • Baader MPCC coma corrector (required for coma correction)

The setup weights around 48 lb what is just right for the CGE mount, at least based on my CGE1400 experience. I have an Orion collimating laser that I originally bought for Antares XT10 Dobsonian, and it seems to be working well, here as well. I also use barlowed laser collimator that I got for Obsession, which seems to be a bit more precise.

Original focuser that comes with the OTA (Orion 2" Crayford focuser) is too high to come in focus with a DSLR or QHY8 cameras using Baader MPCC, there is not enough in-travel. I have replaced it with 2" Orion Low-Profile Dual Speed Crayford Focuser. This is much shorter and sturdier focuser, with an extendable tube allowing for both low-profile, and regular configurations. It fits right in the same place as the regular focuser, so there is no need to drill or modify the OTA. It allowed me to focus both a Canon 40D and QHY8, and finally I was able to start imaging. Pictures below show Orion Low-Profile Crayford with QHY8, the scope is set up for guiding through piggybacked C80ED.

The problems started when I tried to add more hardware on the camera side - Astronomik filter drawer, off-axis guider with guiding camera etc. My regular imaging camera changed to Canon T2i with filters removed, which is heavier than QHY8. The weight become too much for this focuser to handle and it wasn't able to keep focus in configurations where the camera was hanging below OTA or was sitting right on the top of it. I decided to upgrade to one of the heavy duty Crayford focusers capable of handling heavy imaging equipment. I decided to buy JMI Event Horizon EV-1nM since I have good experience with other JMI products. Unfortunately EV-1 base is very different from Orion focusers, the screw holes fall just on the edge of the big focuser hole in the tube. The only way was to add two pieces of black .25in plastic to fit one inside and one outside the tube, and drill screw holes through them instead. As a positive side effect, this plastic-metal-plastic sandwich makes the focuser mounting very rigid. I heated the plastic (above the kitchen range) and curved it such that it fited snugly on 10" tube. Then I drilled big hole for focuser tube, 4 holes for focuser mounting and 4 holes for screws attaching plastic to the OTA. I had to drill 4 screw holes in OTA as well, to secure the plastic. It sounds complicated, but in reality it is not, the whole procedure took just one afternoon. The screws on the inside OTA were painted with black matt metal paint to avoid reflections. For more about imaging with Orion 10" please see "Imaging with O10" section.