Tuesday, 17 May 2011 | Piotr
I had C8 for some time (around a year). It weights less than a 150/750 SW Newtonian, and is quite compact. I used it primarily for planetary/lunar imaging with DMK21 and DSI III Pro cameras (lunar and some deep sky). It's the most mobile big aperture scope ever made
As you focus the primary mirror moves so for fine focusing in planetary/lunar imaging you need a motorised crayford or a crayford focuser with suitable focus motor. For deep sky imaging a Bahtinov mask will do (for planetary the planet is to big, but on Jupiter one of the moons will be ok). I used JMI motorised crayford and fine-focus with it using the live view from the camera (but you can't look on from a short distance - around 1m or less - more when you have bigger scale).
Deep sky imaging - you will probably want the f/6.3 reducer. I use it with Celestron Radial Guider (OAG guider), BS Astro manual filter wheel (like Atik) and DSI III Pro camera. DMK21 was the guider. The scale at bin 1 is still very big, so efficient guiding is required (I used sub-second exposures and low-power corrections - PHD, HEQ5 SynScan).
Cooling is rather quick. Can't provide any numbers, but 30-45 minutes were ok at summer, spring. In winter 1-1.5 hour would do I guess. I did not need a cooler.
Eyepieces: Erfle based eyepieces work very nicely. They are economical wide-field eyepieces that when used with f/10 SCTs don't have any noticeable issues with field correction. William Optics SWAN eyepieces are similar.