rainer725

Just a question for clarification: I'm using an external light meter. For example, if the light meter measures F2.8, ISO 1600, 180°, how do I have to correct it? Is F2.8 + 1 2/3 stops correct (resulting in F4 2/3, ISO 1600, 180°), or would it be acceptable to just decrease the ISO by 2 steps (resulting in F2.8, ISO 400, 180°, with a slight underexposure)?