I have a Canon EOS Rebel camera, and a Meade ETX90 telescope. I have been able to take nice photos, through the telescope without any problem. I purchased a canon teleconverter, and tried to double the focal length that way. However, I get an error message in the camera screen. It is a "bc" error code, and according to Canon, normally is for low battery. However, in this case, it means that I am using a third-party lens, namely the telescope. If anyone out there has been able to get around this problem, please let me know!