Canon Community

Hi Folks,  So I have a Canon 7D and a 70-200mm EF lens. I got givena 1.4X EF extender. Question. What's the overall focal length? is it 1.6 (crop factor) X 1.4 (extender) x 70 (at low end) = ~157mm (or 448mm at high end) or is it 98mm at low end 'cro...

Hi, The autofocus will not work whatever lens I attach to my 7D. On a 70-200mm I hear I whiring noise in the camera and a weak sounding of the lens focusing.  The contacts are clean. I've reset all the camera settings. I can manually shoot and the ph...