[DonAndre]

Exposure time in studio setups with flash light do not really influence the result (I assume you're not doing some high-speed stunning freeze-action shots). The flash is just a tiny fraction of the exposure time, but is responsible for the whole exposure. So increasing or decreasing your exposure time does not really change anything. ISO is better be left at the base value. You should always have enough light to get a proper exposure even at base ISO.



The only thing that changes is aperture. You take some readings here and there with the light meter to see how much light will be received. Take a look at this video: http://layersmagazine.com/studio-photogr...meter.html