xiichakras

Thanks for the reply Micheal, I'll give that a shot the next clear night I get! Thanks again

I have an Orion 8" f8 Ritchey-Chretien telescope and I'm trying to figure out the correct extension spacing from the back of my RC telescope while using a focal reducer. I'm using a TS optics 2" ccd47 .67x focal reducer and the stated distance from sensor of camera to the reducer is between 70-90mm with 85mm being the preferred or ideal distance. I've got the spacing to 82.78mm distance from the sensor and I'm curious if this distance is supposed to be "subtracted" from the back focus of the telescope with the extension rings? The telescope came with one 2 inch and two 1 inch extensions for back focus from the telescope, should I use just one 1 inch extension ring, or no extension rings and just attach the focuser straight to the back of the telescope, or a specific combination? I've included an image to help explain my question. The left side is the telescopes manual image train examples and on the right side is a representation of my question. Also when attaching the camera with the 82mm extension tubes and the focal reducer together would you insert the whole setup inside the focuser until the camera is flush with the focuser, or merely insert just the reducer in the focuser and tighten it down that way? (which im assuming is the correct way based on images I've seen with different setups) Telescope: Orion 8" f/8 Ritchey-Chretien Astrograph (1600mm focal length) Camera: Altair Hypercam 183c pro Camera specs: Sensor size 1" (15.86mm diagonal) Pixel Size 2.4um Resolution 5440 x 3648