A:AnswerEven with stabilization, I was advised to use a tripod. This reduces minor focus errors made with our eye and holding the camera in hand. A small error gets wider the farther away your subject is. A quarter inch up close can be a foot at 50 yards / 150 feet.
A:AnswerYou need a lens mount adaptor so the lens to fit any E0S model. The lens mount adaptor I have for my E0S R6 description says;
Canon - EF-EOS R5, EOS R6, EOS R and EOS RP Lens Mount Adapter.