I too use the Alpha1 and FE 200-600. I shoot full manual because I have not been successful with auto ISO picking the right exposure under common (for me) circumstances, e.g., strong backlighting or a sunlit bird on a shadowed background. I have to admit that I did the experiments shortly after buying the combination, and I was not as experienced with it at the time. Do you have some wisdom/secret you could disclose about shooting auto ISO?