Jorge. I still own two Canon EOS 5D Mark 1's, With the exception of the Sonnar T* FE 35mm f/2,8, all of the other lenses have a ZE Mount and fit straight on the 5D. The 5D's are worth nothing these days so I am keeping both of them. If necessary, one can be cannabilised for spare parts later on. They sill are capable of taking excellent images. I thought of trading in my Sony Alpha 7R Mark 1 but the secondhand value is so poor that I have not bothered. The Sony Alpha 7R Mark II has 5 Axis Image Stabilisation and a lower vibration Shutter, but most of my images are shot from a tripod so that IS would not be enough on its own for me to take that large a financial hit. My gut feeling is that Sony cameras will be like Japanse Hi-Fi, worth next to nothing after 12 months. Resale value is so poor. Steve