I possess two Canon DSLRs and two Sony mirrorless compact system cameras. The big full frame Canon I find too heavy to carry around, and, outdoors, I tend to use the Sony most of the time. However I have a small collection of good Canon lenses that might be useful on the smaller camera. You can buy cheap adapters to fit Canon lenses to Sony cameras, but they do not allow adjustment of the lens aperture, auto focus, or in lens image stabilisation. Alternatively you can spend rather a lot of cash and buy a top of the range adapter, e.g. Metabones, which will give full electronic contact between camera and lens. I don't think that I will be making that much use of my Canon lenses on the Sony, as carrying heavy full frame lenses rather defeats the purpose of using a lightweight compact camera. However I would like to make occasional use of them, possibly in connection with a tripod, and the lens that I would particularly like to fit is my Sigma APO 100-300 f4 . I used t...