|
Hi Niv,
My first design was guess work, and it was too long for my 12" Saxon f5 dob to get into focus using the 1.25" poly pipe, and so I took the 2" to 1.25" adapter out of the telescope draw tube. I could then get most of the camera into the tube so that the ccd was only about 5cm further out from the end of the draw tube. So the photo showing the camera in the telescope did not actually allow it to come into focus being that far out. In general a camera will need to be closer than an eyepiece, so I remade the camera allowing the ccd to be only a few cm past the end of the draw tube. I figured that since I have both a 35mm and a 50mm extension tube then this was the most flexible solution. I have only tried my new shorter web-cam on a friends Skywatcher ED80, and without any extension tubes it came into focus with only 1 or 2 cm free travel with the draw tube almost all the way in. So make the camera body as short as you can.
Cheers Tim.
|